swamp_script_parser/
lib.rs

1/*
2 * Copyright (c) Peter Bjorklund. All rights reserved. https://github.com/swamp/script
3 * Licensed under the MIT License. See LICENSE in the project root for license information.
4 */
5pub mod prelude;
6
7use pest::error::{Error, ErrorVariant, InputLocation};
8use pest::iterators::Pair;
9use pest::{Parser, Position};
10use pest_derive::Parser;
11use std::iter::Peekable;
12use std::str::Chars;
13use swamp_script_ast::{
14    AssignmentOperatorKind, BinaryOperatorKind, CompoundOperator, CompoundOperatorKind,
15    EnumVariantLiteral, ExpressionKind, FieldExpression, FieldName, ForPattern, ForVar,
16    ImportItems, IterableExpression, LocalConstantIdentifier,
17    LocalTypeIdentifierWithOptionalTypeVariables, Mod, NamedStructDef, PatternElement,
18    QualifiedIdentifier, RangeMode, SpanWithoutFileId, StructTypeField, TypeForParameter,
19    TypeVariable, VariableBinding, prelude::*,
20};
21use swamp_script_ast::{Function, WhenBinding};
22use swamp_script_ast::{LiteralKind, MutableOrImmutableExpression};
23use swamp_script_ast::{Postfix, PostfixChain};
24use tracing::error;
25
26pub struct ParseResult<'a> {
27    #[allow(dead_code)]
28    script: String, // Pairs are referencing the script
29    pairs: pest::iterators::Pairs<'a, Rule>,
30}
31
32pub struct GeneralError {
33    pub description: String,
34}
35
36#[derive(Debug)]
37pub enum SpecificError {
38    CouldNotMoveDown,
39    CouldNotMoveRight,
40    General(String),
41    ExpectingTypeIdentifier,
42    ExpectingInnerPair,
43    UnexpectedTypeRule,
44    ExpectedTypeIdentifier(String),
45    ExpectedLocalTypeIdentifier(String),
46    UnexpectedRuleInParseScript(String),
47    ExpectedControlStatement(String),
48    ExpectedStatement(String),
49    ExpectedIfOrElse(String),
50    MissingFunctionSignature,
51    MissingFunctionBody,
52    ExpectedStatementBlock,
53    ExpectedFunctionDefinition,
54    ExpectedParameter,
55    ExpectedImplItem,
56    ExpectedMemberSignature,
57    ExpectedBlockInWhileLoop,
58    UnexpectedExpressionType(String),
59    UnexpectedAccessType(String),
60    UnknownAssignmentOperator(String),
61    CompoundOperatorCanNotContainMut,
62    InvalidAssignmentTarget,
63    CompoundOperatorCanNotHaveMultipleVariables,
64    ExpectedExpressionAfterPrefixOperator,
65    UnknownOperator(String),
66    UnexpectedPostfixOperator,
67    UnexpectedUnaryOperator(String),
68    InvalidMemberCall,
69    UnknownMatchType,
70    UnexpectedElementInPatternList,
71    InvalidPrecisionValue,
72    InvalidPrecisionType,
73    ExpectedTypeIdentifierAfterPath,
74    UnexpectedPatternListElement(String),
75    MustHaveAtLeastOneArm,
76    UnexpectedMatchArmRule(String),
77    UnknownEnumVariant(String),
78    UnknownLiteral,
79    UnknownPrimary(String),
80    InvalidFormatSpecifier,
81    UnexpectedVariantField,
82    MutOnlyForVariables,
83    UnexpectedTokenInFunctionCall,
84    ExpectedExpressionInInterpolation,
85    UnexpectedRuleInInterpolation,
86    ExpectedForPattern,
87    ExpectedBlock,
88    InvalidForPattern,
89    UnexpectedRuleInElse(String),
90    ExpectedLocationExpression,
91    ExpectedImportPath,
92    ExpectedIdentifier,
93    ExpectedIdentifierAfterPath,
94    ExpectedFieldOrRest,
95    UnknownEscapeCharacter(char),
96    UnfinishedEscapeSequence,
97    InvalidUnicodeEscape,
98    InvalidHexEscape,
99    InvalidUtf8Sequence,
100    MissingTypeName,
101    UnknownTerm(String),
102    UnknownExpr(String),
103    UnexpectedTokenInMutableExpression,
104}
105
106#[derive(Debug)]
107pub struct ParseError {
108    pub span: SpanWithoutFileId,
109    pub specific: SpecificError,
110}
111
112#[derive(Parser)]
113#[grammar = "grammar.pest"]
114pub struct ScriptParser;
115
116pub const UNKNOWN_FILE_ID: u16 = 0xffff;
117
118pub struct AstParser;
119
120impl From<Error<Rule>> for ParseError {
121    fn from(value: Error<Rule>) -> Self {
122        let span = match value.location {
123            InputLocation::Pos(pos) => SpanWithoutFileId {
124                offset: pos as u32,
125                length: 1,
126            },
127            InputLocation::Span((start, end)) => SpanWithoutFileId {
128                offset: start as u32,
129                length: (end - start) as u16,
130            },
131        };
132        Self {
133            span,
134            specific: SpecificError::General(value.variant.to_string()),
135        }
136    }
137}
138
139impl AstParser {
140    fn next_pair<'a>(
141        pairs: &mut impl Iterator<Item = Pair<'a, Rule>>,
142    ) -> Result<Pair<'a, Rule>, ParseError> {
143        Ok(pairs.next().ok_or_else(|| {
144            Error::new_from_pos(
145                ErrorVariant::CustomError {
146                    message: "Expected more tokens".into(),
147                },
148                Position::from_start(""),
149            )
150        })?)
151    }
152
153    fn expect_next<'a>(
154        pairs: &mut impl Iterator<Item = Pair<'a, Rule>>,
155        expected_rule: Rule,
156    ) -> Result<Pair<'a, Rule>, ParseError> {
157        let pair = Self::next_pair(pairs)?;
158        if pair.as_rule() != expected_rule {
159            return Err(Error::new_from_span(
160                ErrorVariant::CustomError {
161                    message: format!("Expected {:?}, found {:?}", expected_rule, pair.as_rule()),
162                },
163                pair.as_span(),
164            ))?;
165        }
166        Ok(pair)
167    }
168
169    fn expect_identifier_next<'a>(
170        &self,
171        pairs: &mut impl Iterator<Item = Pair<'a, Rule>>,
172    ) -> Result<LocalIdentifier, ParseError> {
173        let pair = Self::expect_next(pairs, Rule::identifier)?;
174        Ok(LocalIdentifier::new(self.to_node(&pair)))
175    }
176
177    fn expect_function_identifier_next<'a>(
178        &self,
179        pairs: &mut impl Iterator<Item = Pair<'a, Rule>>,
180    ) -> Result<LocalIdentifier, ParseError> {
181        let pair = Self::expect_next(pairs, Rule::function_identifier)?;
182        Ok(LocalIdentifier::new(self.to_node(&pair)))
183    }
184
185    fn expect_constant_identifier_next<'a>(
186        &self,
187        pairs: &mut impl Iterator<Item = Pair<'a, Rule>>,
188    ) -> Result<LocalConstantIdentifier, ParseError> {
189        let pair = Self::expect_next(pairs, Rule::constant_identifier)?;
190        Ok(LocalConstantIdentifier(self.to_node(&pair)))
191    }
192
193    fn _expect_variable_next<'a>(
194        &self,
195        pairs: &mut impl Iterator<Item = Pair<'a, Rule>>,
196    ) -> Result<Variable, ParseError> {
197        let identifier = self.expect_identifier_next(pairs)?;
198        Ok(Variable {
199            name: identifier.0,
200            is_mutable: None,
201        })
202    }
203
204    fn expect_field_label_next<'a>(
205        &self,
206        pairs: &mut impl Iterator<Item = Pair<'a, Rule>>,
207    ) -> Result<FieldName, ParseError> {
208        let field_label_pair = Self::expect_next(pairs, Rule::field_label)?;
209        let mut inner = field_label_pair.clone().into_inner();
210        let ident_pair = inner.next().ok_or_else(|| {
211            self.create_error_pair(SpecificError::ExpectedIdentifier, &field_label_pair)
212        })?;
213
214        Ok(FieldName(self.to_node(&ident_pair)))
215    }
216
217    fn parse_dot_identifier<'a>(&self, pair: &Pair<Rule>) -> Result<FieldName, ParseError> {
218        assert_eq!(pair.as_rule(), Rule::dot_identifier);
219        let mut inner = pair.clone().into_inner();
220        let ident_pair = inner
221            .next()
222            .ok_or_else(|| self.create_error_pair(SpecificError::ExpectedIdentifier, &pair))?;
223
224        Ok(FieldName(self.to_node(&ident_pair)))
225    }
226
227    fn expect_local_type_identifier_next<'a>(
228        &self,
229        pairs: &mut impl Iterator<Item = Pair<'a, Rule>>,
230    ) -> Result<LocalTypeIdentifier, ParseError> {
231        let pair = Self::expect_next(pairs, Rule::type_identifier)?;
232        Ok(LocalTypeIdentifier::new(self.to_node(&pair)))
233    }
234
235    /*
236    fn expect_qualified_type_identifier_next<'a>(
237        &self,
238        inner_pairs: &mut impl Iterator<Item = Pair<'a, Rule>>,
239    ) -> Result<QualifiedTypeIdentifier, ParseError> {
240        let first = Self::next_pair(inner_pairs)?;
241        match first.as_rule() {
242            Rule::module_segments => {
243                let module_path = self.parse_module_segments(first.clone());
244                let type_id = inner_pairs.next().ok_or_else(|| {
245                    self.create_error_pair(SpecificError::ExpectedTypeIdentifierAfterPath, &first)
246                })?;
247
248                let type_identifier = self.parse_local_type_identifier(&type_id)?;
249                Ok(QualifiedTypeIdentifier::new(type_identifier, module_path))
250            }
251            Rule::type_identifier => Ok(QualifiedTypeIdentifier::new(
252                LocalTypeIdentifier(self.to_node(&first)),
253                Vec::new(),
254            )),
255            _ => Err(self.create_error_pair(
256                SpecificError::ExpectedTypeIdentifier(Self::pair_to_rule(&first)),
257                &first,
258            )),
259        }
260    }
261
262     */
263
264    fn convert_into_iterator<'a>(pair: &'a Pair<'a, Rule>) -> impl Iterator<Item = Pair<'a, Rule>> {
265        pair.clone().into_inner()
266    }
267
268    fn create_error_pair(&self, kind: SpecificError, pair: &Pair<Rule>) -> ParseError {
269        ParseError {
270            span: self.to_span(pair.as_span()),
271            specific: kind,
272        }
273    }
274
275    fn to_err(kind: SpecificError, pair: &Pair<Rule>) -> ParseError {
276        ParseError {
277            span: Self::span(pair.as_span()),
278            specific: kind,
279        }
280    }
281
282    fn next_inner_pair<'a>(&self, pair: &Pair<'a, Rule>) -> Result<Pair<'a, Rule>, ParseError> {
283        let _span = pair.as_span();
284        pair.clone()
285            .into_inner()
286            .next()
287            .ok_or_else(move || self.create_error_pair(SpecificError::ExpectingInnerPair, pair))
288    }
289
290    pub fn parse(rule: Rule, raw_script: &str) -> Result<ParseResult<'static>, ParseError> {
291        let pairs = unsafe {
292            std::mem::transmute::<pest::iterators::Pairs<'_, Rule>, pest::iterators::Pairs<'_, Rule>>(
293                ScriptParser::parse(rule, raw_script)?,
294            )
295        };
296        Ok(ParseResult {
297            script: raw_script.to_string(),
298            pairs,
299        })
300    }
301
302    pub fn parse_module(&self, raw_script: &str) -> Result<Module, ParseError> {
303        let result = Self::parse(Rule::program, raw_script)?;
304
305        let mut pairs = result.pairs;
306
307        let program_pair = Self::next_pair(&mut pairs)?;
308
309        let mut expressions = Vec::new();
310        let mut definitions = Vec::new();
311        for pair in Self::convert_into_iterator(&program_pair) {
312            match pair.as_rule() {
313                Rule::definition => {
314                    let def = self.parse_definition(&pair)?;
315                    definitions.push(def);
316                }
317                Rule::expression => {
318                    let expr = self.parse_expression(&pair)?;
319                    expressions.push(expr);
320                }
321                Rule::EOI => {} // End of Input - do nothing
322                _ => {
323                    return Err(self.create_error_pair(
324                        SpecificError::UnexpectedRuleInParseScript(Self::pair_to_rule(&pair)),
325                        &pair,
326                    ));
327                }
328            }
329        }
330
331        let maybe_expression = match expressions.len() {
332            0 => None,
333            1 => Some(expressions.into_iter().next().unwrap()),
334            _ => Some(Expression {
335                kind: ExpressionKind::Block(expressions),
336                node: Node {
337                    span: SpanWithoutFileId::default(),
338                },
339            }),
340        };
341
342        Ok(Module::new(definitions, maybe_expression))
343    }
344
345    fn parse_definition(&self, pair: &Pair<Rule>) -> Result<Definition, ParseError> {
346        let inner_pair = self.next_inner_pair(pair)?;
347        match inner_pair.as_rule() {
348            Rule::impl_def => self.parse_impl_def(&inner_pair),
349            Rule::const_def => self.parse_const_definition(&inner_pair),
350            Rule::struct_def => self.parse_struct_def(&inner_pair),
351            Rule::type_def => self.parse_type_def(&inner_pair),
352            Rule::function_def => self.parse_function_def(&inner_pair),
353            Rule::use_def => self.parse_use(&inner_pair),
354            Rule::mod_def => self.parse_mod(&inner_pair),
355            Rule::enum_def => self.parse_enum_def(&inner_pair),
356            _ => todo!(),
357        }
358    }
359
360    fn parse_const_definition(&self, pair: &Pair<Rule>) -> Result<Definition, ParseError> {
361        Ok(Definition::Constant(self.parse_const_info(pair)?))
362    }
363
364    fn parse_const_info(&self, pair: &Pair<Rule>) -> Result<ConstantInfo, ParseError> {
365        let mut inner = Self::convert_into_iterator(pair);
366        let constant_identifier = self.expect_constant_identifier_next(&mut inner)?;
367        let expr_pair = Self::next_pair(&mut inner)?;
368        let expression = self.parse_expression(&expr_pair)?;
369
370        Ok(ConstantInfo {
371            constant_identifier,
372            expression: Box::new(expression),
373        })
374    }
375
376    fn module_path_and_items(
377        &self,
378        pair: &Pair<Rule>,
379    ) -> Result<(Vec<Node>, ImportItems), ParseError> {
380        let mut inner = Self::convert_into_iterator(pair);
381        let import_path = Self::next_pair(&mut inner)?;
382
383        let mut segments = Vec::new();
384        for pair in import_path.into_inner() {
385            segments.push(self.to_node(&pair));
386        }
387
388        let items = match inner.next() {
389            Some(found_rule) => match found_rule.as_rule() {
390                Rule::all_imports => ImportItems::All,
391                Rule::import_list => {
392                    let mut imported_items = Vec::new();
393                    for list_item in found_rule.into_inner() {
394                        let item = Self::next_pair(&mut list_item.into_inner())?;
395
396                        let import_item = match item.as_rule() {
397                            Rule::identifier => {
398                                ImportItem::Identifier(LocalIdentifier::new(self.to_node(&item)))
399                            }
400                            Rule::type_identifier => {
401                                ImportItem::Type(LocalTypeIdentifier::new(self.to_node(&item)))
402                            }
403                            _ => {
404                                return Err(self
405                                    .create_error_pair(SpecificError::ExpectedIdentifier, &item));
406                            }
407                        };
408
409                        imported_items.push(import_item);
410                    }
411                    if imported_items.is_empty() {
412                        ImportItems::Nothing
413                    } else {
414                        ImportItems::Items(imported_items)
415                    }
416                }
417                _ => panic!("was not all_imports or import_list"),
418            },
419            None => ImportItems::Nothing,
420        };
421
422        Ok((segments, items))
423    }
424
425    fn parse_use(&self, pair: &Pair<Rule>) -> Result<Definition, ParseError> {
426        let (segments, items) = self.module_path_and_items(&pair)?;
427
428        Ok(Definition::Use(Use {
429            module_path: ModulePath(segments),
430            items,
431        }))
432    }
433
434    fn parse_mod(&self, pair: &Pair<Rule>) -> Result<Definition, ParseError> {
435        let (segments, items) = self.module_path_and_items(&pair)?;
436
437        Ok(Definition::Mod(Mod {
438            module_path: ModulePath(segments),
439            items,
440        }))
441    }
442
443    fn pair_to_rule(rule: &Pair<Rule>) -> String {
444        format!("{:?}", rule.as_rule())
445    }
446
447    fn parse_block(&self, block_pair: &Pair<Rule>) -> Result<Expression, ParseError> {
448        if block_pair.as_rule() != Rule::block {
449            return Err(self.create_error_pair(SpecificError::ExpectedBlock, block_pair));
450        }
451
452        let mut expressions = Vec::new();
453
454        for pair in Self::convert_into_iterator(block_pair) {
455            if pair.as_rule() != Rule::expression {
456                return Err(self.create_error_pair(
457                    SpecificError::UnexpectedRuleInParseScript(format!(
458                        "Expected expression_in_block, got: {:?}",
459                        pair.as_rule()
460                    )),
461                    block_pair,
462                ));
463            }
464
465            match pair.as_rule() {
466                Rule::expression => {
467                    let expr = self.parse_expression(&pair)?;
468                    expressions.push(expr);
469                }
470                _ => {
471                    return Err(self.create_error_pair(
472                        SpecificError::UnexpectedRuleInParseScript(format!(
473                            "Unexpected rule in parse_block: {:?}",
474                            pair.as_rule()
475                        )),
476                        &pair,
477                    ));
478                }
479            }
480        }
481
482        let block_expr = self.create_expr(ExpressionKind::Block(expressions), block_pair);
483        Ok(block_expr)
484    }
485
486    fn parse_with_expr(&self, pair: &Pair<Rule>) -> Result<Expression, ParseError> {
487        let mut inner = Self::convert_into_iterator(pair);
488        let binding_list_pair = inner.next().expect("variable list missing");
489        let binding_list = self.parse_variable_binding_list(&binding_list_pair)?;
490
491        let expr_pair = inner.next().expect("block missing");
492        let expr = self.parse_expression(&expr_pair)?;
493
494        let with_expr = self.create_expr(ExpressionKind::With(binding_list, Box::from(expr)), pair);
495        Ok(with_expr)
496    }
497
498    fn parse_when_expr(&self, pair: &Pair<Rule>) -> Result<Expression, ParseError> {
499        let mut inner = Self::convert_into_iterator(pair);
500        let binding_list =
501            self.parse_when_variable_binding_list(&inner.next().expect("variable list missing"))?;
502        let expr = self.parse_expression(&inner.next().expect("block missing"))?;
503
504        let next = inner.next();
505        let else_expr = if let Some(found_else) = next {
506            Some(Box::new(self.parse_expression(&found_else)?))
507        } else {
508            None
509        };
510
511        Ok(self.create_expr(
512            ExpressionKind::When(binding_list, Box::from(expr), else_expr),
513            pair,
514        ))
515    }
516
517    fn parse_variable_binding_list(
518        &self,
519        pair: &Pair<Rule>,
520    ) -> Result<Vec<VariableBinding>, ParseError> {
521        let inner = Self::convert_into_iterator(pair);
522        let mut bindings = Vec::new();
523
524        // Each item in inner will be a variable_binding
525        for binding_pair in inner {
526            if binding_pair.as_rule() == Rule::variable_binding {
527                bindings.push(self.parse_variable_binding(&binding_pair)?);
528            }
529        }
530
531        Ok(bindings)
532    }
533
534    fn parse_variable_binding(&self, pair: &Pair<Rule>) -> Result<VariableBinding, ParseError> {
535        let mut inner = Self::convert_into_iterator(pair);
536
537        let variable = self.parse_variable_item(&inner.next().expect("variable missing"))?;
538
539        let expression = match inner.next() {
540            Some(expr_pair) => self.parse_mutable_or_immutable_expression(&expr_pair)?,
541            _ => MutableOrImmutableExpression {
542                expression: self
543                    .create_expr(ExpressionKind::VariableReference(variable.clone()), pair),
544                is_mutable: None,
545            },
546        };
547
548        Ok(VariableBinding {
549            variable,
550            expression,
551        })
552    }
553
554    fn parse_when_variable_binding(&self, pair: &Pair<Rule>) -> Result<WhenBinding, ParseError> {
555        let mut inner = Self::convert_into_iterator(pair);
556
557        let variable = self.parse_variable_item(&inner.next().expect("variable missing"))?;
558
559        let expression = match inner.next() {
560            Some(expr_pair) => Some(self.parse_mutable_or_immutable_expression(&expr_pair)?),
561            _ => None,
562        };
563
564        Ok(WhenBinding {
565            variable,
566            expression,
567        })
568    }
569
570    fn parse_when_variable_binding_list(
571        &self,
572        pair: &Pair<Rule>,
573    ) -> Result<Vec<WhenBinding>, ParseError> {
574        let inner = Self::convert_into_iterator(pair);
575        let mut bindings = Vec::new();
576
577        // Each item in inner will be a variable_binding
578        for binding_pair in inner {
579            if binding_pair.as_rule() == Rule::variable_when_binding {
580                bindings.push(self.parse_when_variable_binding(&binding_pair)?);
581            }
582        }
583
584        Ok(bindings)
585    }
586
587    fn parse_if_expression(&self, pair: &Pair<Rule>) -> Result<Expression, ParseError> {
588        let mut inner = Self::convert_into_iterator(pair);
589        let condition = self.parse_expression(&Self::next_pair(&mut inner)?)?;
590        let then_branch = self.parse_expression(&Self::next_pair(&mut inner)?)?;
591        let else_branch = inner
592            .next()
593            .map(|p| {
594                match p.as_rule() {
595                    Rule::if_expr => self.parse_if_expression(&p), // Recursively handle `else if`
596                    _ => self.parse_expression(&p),                // Inline or block `else`
597                }
598            })
599            .transpose()?;
600
601        Ok(self.create_expr(
602            ExpressionKind::If(
603                Box::new(condition),
604                Box::new(then_branch),
605                else_branch.map(Box::new),
606            ),
607            pair,
608        ))
609    }
610
611    #[allow(clippy::too_many_lines)]
612    fn parse_postfix_expression(&self, pair: &Pair<Rule>) -> Result<Expression, ParseError> {
613        assert_eq!(pair.as_rule(), Rule::postfix);
614        let mut inner = pair.clone().into_inner();
615
616        let primary_pair = inner.next().ok_or_else(|| {
617            self.create_error_pair(SpecificError::UnexpectedPostfixOperator, pair)
618        })?;
619        let start_expr = self.parse_term(&primary_pair)?;
620        //info!(?start_expr, "start");
621        let mut postfixes = Vec::new();
622        if inner.len() == 0 {
623            return Ok(start_expr);
624        }
625
626        for op_pair in inner.clone() {
627            //info!(rule=?op_pair.as_rule(), "..continuing chain");
628            match op_pair.as_rule() {
629                Rule::postfix_op => {
630                    let mut sub_inner = op_pair.clone().into_inner();
631                    let child = sub_inner.next().ok_or_else(|| {
632                        self.create_error_pair(SpecificError::UnexpectedPostfixOperator, &op_pair)
633                    })?;
634
635                    match child.as_rule() {
636                        Rule::unwrap_postfix => {
637                            postfixes.push(Postfix::OptionUnwrap(self.to_node(&op_pair)));
638                        }
639
640                        Rule::none_coalesce_postfix => {
641                            let mut postfix_inner = Self::convert_into_iterator(&child);
642                            let expr_pair = postfix_inner.next().expect("must have following");
643                            let default_expression = self.parse_expression(&expr_pair)?;
644                            postfixes.push(Postfix::NoneCoalesce(default_expression));
645                        }
646
647                        Rule::function_call_postfix => {
648                            let args = self.parse_function_call_postfix(&child)?;
649                            let node = self.to_node(&op_pair);
650                            postfixes.push(Postfix::FunctionCall(node, args));
651                        }
652
653                        Rule::member_call_postfix => {
654                            let mut inner = child.into_inner();
655
656                            let member_access = Self::next_pair(&mut inner)?;
657                            assert_eq!(member_access.as_rule(), Rule::member_access_postfix);
658                            let mut ma_inner = member_access.into_inner();
659                            let dot_id = Self::next_pair(&mut ma_inner)?;
660                            let member_identifier = self.parse_dot_identifier(&dot_id)?;
661
662                            let args_pair = Self::next_pair(&mut inner)?;
663                            let args = self.parse_function_call_arguments(&args_pair)?;
664
665                            postfixes.push(Postfix::MemberCall(member_identifier.0, args));
666                        }
667
668                        Rule::member_access_postfix => {
669                            let mut inner = child.into_inner();
670                            let dot_id = Self::next_pair(&mut inner)?;
671                            let identifier = self.parse_dot_identifier(&dot_id)?;
672                            postfixes.push(Postfix::FieldAccess(identifier.0));
673                        }
674
675                        Rule::subscript_postfix => {
676                            let mut arr_inner = child.clone().into_inner();
677                            let index_pair = arr_inner.next().ok_or_else(|| {
678                                self.create_error_pair(
679                                    SpecificError::UnexpectedPostfixOperator,
680                                    &child,
681                                )
682                            })?;
683                            let index_expr = self.parse_expression(&index_pair)?;
684                            postfixes.push(Postfix::Subscript(index_expr));
685                        }
686
687                        _ => {
688                            return Err(self.create_error_pair(
689                                SpecificError::UnexpectedPostfixOperator,
690                                &child,
691                            ));
692                        }
693                    }
694                }
695                _ => {
696                    return Err(
697                        self.create_error_pair(SpecificError::UnexpectedPostfixOperator, &op_pair)
698                    );
699                }
700            }
701        }
702
703        Ok(self.create_expr(
704            ExpressionKind::PostfixChain(PostfixChain {
705                base: Box::from(start_expr),
706                postfixes: postfixes,
707            }),
708            pair,
709        ))
710    }
711
712    fn parse_type_def(&self, pair: &Pair<Rule>) -> Result<Definition, ParseError> {
713        let mut inner = Self::convert_into_iterator(pair);
714        let alias_name = self.expect_local_type_identifier_next(&mut inner)?;
715        let referenced_type = self.parse_type(inner.next().expect("should work"))?;
716
717        let alias_type = AliasType {
718            identifier: alias_name,
719            referenced_type,
720        };
721
722        Ok(Definition::AliasDef(alias_type))
723    }
724
725    fn parse_struct_type_field(&self, pair: &Pair<Rule>) -> Result<StructTypeField, ParseError> {
726        assert_eq!(pair.as_rule(), Rule::struct_type_field);
727
728        let mut field_inner = Self::convert_into_iterator(&pair);
729        let field_name = self.expect_field_label_next(&mut field_inner)?;
730        let field_type = self.parse_type(Self::next_pair(&mut field_inner)?)?;
731        let struct_type_field = StructTypeField {
732            field_name,
733            field_type,
734        };
735
736        Ok(struct_type_field)
737    }
738
739    fn parse_struct_type_fields(
740        &self,
741        pair: &Pair<Rule>,
742    ) -> Result<Vec<StructTypeField>, ParseError> {
743        assert_eq!(pair.as_rule(), Rule::struct_type_fields);
744        let mut fields = Vec::new();
745        for field_def in Self::convert_into_iterator(pair) {
746            let anonymous_struct_field = self.parse_struct_type_field(&field_def)?;
747
748            fields.push(anonymous_struct_field);
749        }
750        Ok(fields)
751    }
752
753    fn parse_struct_type(&self, pair: &Pair<Rule>) -> Result<AnonymousStructType, ParseError> {
754        assert_eq!(pair.as_rule(), Rule::struct_type);
755        let fields = Self::right_alternative(pair)?;
756        let fields = self.parse_struct_type_fields(&fields)?;
757        let struct_type = AnonymousStructType::new(fields);
758        Ok(struct_type)
759    }
760
761    fn parse_tuple_type_elements(&self, pair: &Pair<Rule>) -> Result<Vec<Type>, ParseError> {
762        assert_eq!(pair.as_rule(), Rule::tuple_type);
763        let mut types = Vec::new();
764        for type_pair in pair.clone().into_inner() {
765            let type_value = self.parse_type(type_pair)?;
766            types.push(type_value);
767        }
768        Ok(types)
769    }
770
771    fn parse_struct_def(&self, pair: &Pair<Rule>) -> Result<Definition, ParseError> {
772        let mut inner = Self::convert_into_iterator(pair).peekable();
773
774        let name_with_optional_type_params =
775            self.parse_local_type_identifier_with_optional_type_variables(&inner.next().unwrap())?;
776
777        // struct_type is optional
778        // it is valid syntax to just do:
779        // `struct SomeStruct`
780        let struct_type_pair_option = inner.next();
781        let struct_type_result = match struct_type_pair_option {
782            Some(struct_type_pair) => Some(self.parse_struct_type(&struct_type_pair)?),
783            None => None,
784        };
785
786        let struct_type = struct_type_result.map_or_else(
787            || AnonymousStructType::new(vec![]),
788            |found_result| found_result,
789        );
790
791        Ok(Definition::NamedStructDef(NamedStructDef {
792            identifier: name_with_optional_type_params,
793            struct_type,
794        }))
795    }
796
797    fn parse_function_def(&self, pair: &Pair<Rule>) -> Result<Definition, ParseError> {
798        let function_pair = self.next_inner_pair(pair)?;
799
800        match function_pair.as_rule() {
801            Rule::normal_function => {
802                let mut inner = function_pair.clone().into_inner();
803                let signature_pair = inner.next().ok_or_else(|| {
804                    self.create_error_pair(SpecificError::MissingFunctionSignature, &function_pair)
805                })?;
806
807                let signature = self.parse_function_signature(&signature_pair)?;
808
809                let body = self.parse_block(&inner.next().ok_or_else(|| {
810                    self.create_error_pair(SpecificError::MissingFunctionBody, &function_pair)
811                })?)?;
812
813                Ok(Definition::FunctionDef(Function::Internal(
814                    FunctionWithBody {
815                        declaration: signature,
816                        body,
817                    },
818                )))
819            }
820            Rule::external_function => {
821                let signature_pair =
822                    function_pair.clone().into_inner().next().ok_or_else(|| {
823                        self.create_error_pair(
824                            SpecificError::MissingFunctionSignature,
825                            &function_pair,
826                        )
827                    })?;
828
829                let signature = self.parse_function_signature(&signature_pair)?;
830                Ok(Definition::FunctionDef(Function::External(signature)))
831            }
832            _ => {
833                Err(self
834                    .create_error_pair(SpecificError::ExpectedFunctionDefinition, &function_pair))
835            }
836        }
837    }
838    fn parse_function_signature(
839        &self,
840        pair: &Pair<Rule>,
841    ) -> Result<FunctionDeclaration, ParseError> {
842        if pair.as_rule() != Rule::function_signature {
843            return Err(self.create_error_pair(SpecificError::MissingFunctionSignature, pair));
844        }
845
846        let mut inner = pair.clone().into_inner();
847
848        let function_name = self.expect_function_identifier_next(&mut inner)?;
849
850        let next_token = inner.next();
851        let (parameters, return_type) = match next_token {
852            Some(token) if token.as_rule() == Rule::parameter_list => {
853                let params = self.parse_parameters(&token)?;
854
855                let ret_type = if let Some(return_type_pair) = inner.next() {
856                    Some(self.parse_return_type(&return_type_pair)?)
857                } else {
858                    None
859                };
860
861                (params, ret_type)
862            }
863
864            Some(token) if token.as_rule() == Rule::return_type => {
865                (Vec::new(), Some(self.parse_return_type(&token)?))
866            }
867            _ => (Vec::new(), None),
868        };
869
870        Ok(FunctionDeclaration {
871            name: function_name.0,
872            params: parameters,
873            self_parameter: None,
874            return_type,
875        })
876    }
877
878    fn parse_return_type(&self, pair: &Pair<Rule>) -> Result<Type, ParseError> {
879        let inner_pair = self.next_inner_pair(pair)?;
880        self.parse_type(inner_pair)
881    }
882
883    pub fn parse_parameters(&self, pair: &Pair<Rule>) -> Result<Vec<Parameter>, ParseError> {
884        let mut parameters = Vec::new();
885
886        for param_pair in Self::convert_into_iterator(pair) {
887            match param_pair.as_rule() {
888                Rule::parameter => {
889                    let mut iterator = Self::convert_into_iterator(&param_pair);
890                    let may_mut_pair = iterator.next().unwrap();
891                    let var = self.parse_maybe_mut_identifier(&may_mut_pair)?;
892                    let type_pair = iterator.next().unwrap();
893                    let param_type = self.parse_type(type_pair.clone())?;
894
895                    parameters.push(Parameter {
896                        variable: var,
897                        param_type,
898                    });
899                }
900                Rule::self_parameter => {
901                    panic!("should have been handled before parsing parameters")
902                }
903                _ => {
904                    return Err(
905                        self.create_error_pair(SpecificError::ExpectedParameter, &param_pair)
906                    );
907                }
908            }
909        }
910
911        Ok(parameters)
912    }
913
914    fn parse_impl_def(&self, pair: &Pair<Rule>) -> Result<Definition, ParseError> {
915        let mut inner = Self::convert_into_iterator(pair);
916        let name_with_optional_type_params =
917            self.parse_local_type_identifier_with_optional_type_variables(&inner.next().unwrap())?;
918
919        let mut functions = Vec::new();
920
921        for item_pair in inner {
922            if item_pair.as_rule() == Rule::impl_item {
923                let inner_item = self.next_inner_pair(&item_pair)?;
924                match inner_item.as_rule() {
925                    Rule::external_member_function => {
926                        let inner_inner_item = self.next_inner_pair(&inner_item)?;
927                        let signature = self.parse_member_signature(&inner_inner_item)?;
928                        functions.push(Function::External(signature));
929                    }
930                    Rule::normal_member_function => {
931                        let function_data = self.parse_member_data(&inner_item)?;
932                        functions.push(Function::Internal(function_data));
933                    }
934                    _ => {
935                        return Err(
936                            self.create_error_pair(SpecificError::ExpectedImplItem, &inner_item)
937                        );
938                    }
939                }
940            }
941        }
942
943        Ok(Definition::ImplDef(
944            name_with_optional_type_params,
945            functions,
946        ))
947    }
948
949    fn parse_member_signature(&self, pair: &Pair<Rule>) -> Result<FunctionDeclaration, ParseError> {
950        assert_eq!(pair.as_rule(), Rule::member_signature);
951
952        let mut inner = pair.clone().into_inner();
953
954        let name = self.expect_function_identifier_next(&mut inner)?;
955
956        let mut parameters = Vec::new();
957        let mut self_parameter = None;
958        let mut return_type = None;
959
960        for next_pair in inner {
961            match next_pair.as_rule() {
962                Rule::self_parameter => {
963                    let mut mut_keyword_node = None;
964                    let mut self_node = None;
965
966                    for pair in next_pair.into_inner() {
967                        match pair.as_rule() {
968                            Rule::mut_keyword => {
969                                mut_keyword_node = Some(self.to_node(&pair));
970                            }
971                            Rule::self_identifier => {
972                                self_node = Some(self.to_node(&pair));
973                            }
974                            _ => unreachable!("Unexpected rule in self_parameter"),
975                        }
976                    }
977
978                    self_parameter = Some(SelfParameter {
979                        is_mutable: mut_keyword_node,
980                        self_node: self_node.expect("self node must exist"),
981                    });
982                }
983                Rule::parameter_list => {
984                    parameters = self.parse_parameters(&next_pair)?;
985                }
986                Rule::return_type => {
987                    return_type = Some(self.parse_return_type(&next_pair)?);
988                }
989                _ => {}
990            }
991        }
992
993        Ok(FunctionDeclaration {
994            name: name.0,
995            params: parameters,
996            self_parameter,
997            return_type,
998        })
999    }
1000
1001    fn parse_member_data(&self, pair: &Pair<Rule>) -> Result<FunctionWithBody, ParseError> {
1002        if pair.as_rule() != Rule::normal_member_function {
1003            return Err(self.create_error_pair(SpecificError::ExpectedMemberSignature, pair));
1004        }
1005
1006        let mut inner = Self::convert_into_iterator(pair);
1007
1008        let signature_pair = Self::next_pair(&mut inner)?;
1009        let signature = self.parse_member_signature(&signature_pair)?;
1010
1011        let block_pair = Self::next_pair(&mut inner)?;
1012        let body = self.parse_block(&block_pair)?;
1013
1014        Ok(FunctionWithBody {
1015            declaration: signature,
1016            body,
1017        })
1018    }
1019
1020    fn parse_for_loop(&self, pair: &Pair<Rule>) -> Result<Expression, ParseError> {
1021        let mut inner = Self::convert_into_iterator(pair);
1022
1023        let pattern_pair = Self::next_pair(&mut inner)?;
1024        if pattern_pair.as_rule() != Rule::for_pattern {
1025            return Err(self.create_error_pair(SpecificError::ExpectedForPattern, &pattern_pair));
1026        }
1027
1028        let inner_pattern = self.next_inner_pair(&pattern_pair)?;
1029        let pattern = match inner_pattern.as_rule() {
1030            Rule::maybe_mut_identifier => {
1031                let mut inner_iter = inner_pattern.clone().into_inner();
1032                let is_mutable = inner_iter
1033                    .peek()
1034                    .map_or(false, |p| p.as_rule() == Rule::mut_keyword);
1035
1036                let is_mut = if is_mutable {
1037                    let mut_node = self.to_node(&inner_iter.next().unwrap());
1038                    Some(mut_node)
1039                } else {
1040                    None
1041                };
1042
1043                let identifier = if is_mutable {
1044                    self.expect_identifier_next(&mut inner_iter)?.0
1045                } else {
1046                    self.to_node(&inner_pattern)
1047                };
1048
1049                ForPattern::Single(ForVar { identifier, is_mut })
1050            }
1051            Rule::for_pair => {
1052                let mut vars = Self::convert_into_iterator(&inner_pattern);
1053
1054                // Parse first variable in the pair
1055                let first_var_pair = Self::next_pair(&mut vars)?;
1056                let mut first_inner_iter = first_var_pair.clone().into_inner();
1057                let first_is_mut = if first_inner_iter
1058                    .peek()
1059                    .map_or(false, |p| p.as_rule() == Rule::mut_keyword)
1060                {
1061                    Some(self.to_node(&first_inner_iter.next().unwrap()))
1062                } else {
1063                    None
1064                };
1065
1066                let first_identifier = if first_is_mut.is_some() {
1067                    self.expect_identifier_next(&mut first_inner_iter)?.0
1068                } else {
1069                    self.to_node(&first_var_pair)
1070                };
1071
1072                // Parse second variable in the pair
1073                let second_var_pair = Self::next_pair(&mut vars)?;
1074                let mut second_inner_iter = second_var_pair.clone().into_inner();
1075                let second_is_mut = if second_inner_iter
1076                    .peek()
1077                    .map_or(false, |p| p.as_rule() == Rule::mut_keyword)
1078                {
1079                    Some(self.to_node(&second_inner_iter.next().unwrap()))
1080                } else {
1081                    None
1082                };
1083
1084                let second_identifier = if second_is_mut.is_some() {
1085                    self.expect_identifier_next(&mut second_inner_iter)?.0
1086                } else {
1087                    self.to_node(&second_var_pair)
1088                };
1089
1090                ForPattern::Pair(
1091                    ForVar {
1092                        identifier: first_identifier,
1093                        is_mut: first_is_mut,
1094                    },
1095                    ForVar {
1096                        identifier: second_identifier,
1097                        is_mut: second_is_mut,
1098                    },
1099                )
1100            }
1101            _ => {
1102                return Err(
1103                    self.create_error_pair(SpecificError::InvalidForPattern, &inner_pattern)
1104                );
1105            }
1106        };
1107
1108        let next_pair = Self::next_pair(&mut inner)?;
1109        let iterable_expression = self.parse_mutable_or_immutable_expression(&next_pair)?;
1110
1111        let mut_expression = IterableExpression {
1112            expression: Box::new(iterable_expression),
1113        };
1114
1115        let body = self.parse_expression(&Self::next_pair(&mut inner)?)?;
1116
1117        // Return the ForLoop statement with MutExpression
1118        Ok(self.create_expr(
1119            ExpressionKind::ForLoop(pattern, mut_expression, None, Box::from(body)),
1120            pair,
1121        ))
1122    }
1123
1124    fn parse_while_loop(&self, pair: &Pair<Rule>) -> Result<Expression, ParseError> {
1125        let mut inner = Self::convert_into_iterator(pair);
1126
1127        let condition = self.parse_expression(&Self::next_pair(&mut inner)?)?;
1128
1129        let body = self.parse_expression(&Self::next_pair(&mut inner)?)?;
1130
1131        Ok(self.create_expr(
1132            ExpressionKind::WhileLoop(Box::from(condition), Box::from(body)),
1133            pair,
1134        ))
1135    }
1136
1137    fn parse_expression(&self, pair: &Pair<Rule>) -> Result<Expression, ParseError> {
1138        let sub = &Self::right_alternative(pair)?;
1139        match sub.as_rule() {
1140            Rule::expression => {
1141                let inner = self.next_inner_pair(sub)?;
1142
1143                self.parse_expression(&inner)
1144            }
1145
1146            Rule::qualified_identifier => Ok(self.create_expr(
1147                ExpressionKind::VariableReference(Variable::new(self.to_node(sub), None)),
1148                sub,
1149            )),
1150            Rule::block => self.parse_block(sub),
1151
1152            Rule::assignment => self.parse_assignment_expression(sub),
1153            Rule::destructuring_assignment => self.parse_destructuring_assignment(sub),
1154            Rule::variable_definition => self.parse_variable_definition(sub),
1155
1156            Rule::addition => self.parse_addition(sub),
1157            Rule::range => self.parse_range(sub),
1158            Rule::logical => self.parse_logical(sub),
1159            Rule::comparison => self.parse_comparison(sub),
1160            Rule::multiplication => self.parse_multiplication(sub),
1161
1162            Rule::prefix => self.parse_prefix(sub),
1163
1164            Rule::match_expr => self.parse_match_expr(sub),
1165            Rule::map_literal => self.parse_map_literal(sub),
1166            Rule::array_literal => self.parse_array_literal(sub),
1167            Rule::guard_expr => self.parse_guard_expr_list(sub),
1168            Rule::with_expr => self.parse_with_expr(sub),
1169            Rule::when_expr => self.parse_when_expr(sub),
1170            Rule::if_expr => self.parse_if_expression(sub),
1171            Rule::for_loop => self.parse_for_loop(sub),
1172            Rule::while_loop => self.parse_while_loop(sub),
1173
1174            //            Rule::expression | Rule::literal => self.parse_expr(pair),
1175            Rule::prefix_op | Rule::op_neg | Rule::op_not => {
1176                let op = self.parse_unary_operator(sub)?;
1177                let expr = self.parse_postfix_expression(&self.next_inner_pair(sub)?)?;
1178                Ok(self.create_expr(ExpressionKind::UnaryOp(op, Box::new(expr)), sub))
1179            }
1180
1181            //Rule::mut_expression => self.parse_mutable_or_immutable_expression(pair),
1182            Rule::postfix => self.parse_postfix_expression(sub),
1183            _ => Err(self.create_error_pair(
1184                SpecificError::UnexpectedExpressionType(Self::pair_to_rule(sub)),
1185                sub,
1186            )),
1187        }
1188    }
1189
1190    fn parse_variable_list(&self, pair: &Pair<Rule>) -> Result<Vec<Variable>, ParseError> {
1191        let mut variables = Vec::new();
1192        for item_pair in pair.clone().into_inner() {
1193            if item_pair.as_rule() == Rule::variable_item {
1194                variables.push(self.parse_variable_item(&item_pair)?);
1195            }
1196        }
1197        Ok(variables)
1198    }
1199
1200    fn parse_maybe_mut_identifier(&self, pair: &Pair<Rule>) -> Result<Variable, ParseError> {
1201        assert_eq!(pair.as_rule(), Rule::maybe_mut_identifier);
1202        let mut inner = pair.clone().into_inner();
1203        let mut_node = if let Some(peeked) = inner.peek() {
1204            if peeked.as_rule() == Rule::mut_keyword {
1205                // Convert 'mut' to a Node
1206                let node = self.to_node(&peeked);
1207                inner.next(); // consume the 'mut' token
1208                Some(node)
1209            } else {
1210                None
1211            }
1212        } else {
1213            None
1214        };
1215
1216        let name_pair = inner.next().ok_or_else(|| {
1217            self.create_error_pair(
1218                SpecificError::UnexpectedRuleInParseScript(
1219                    "Expected identifier in variable_item".into(),
1220                ),
1221                pair,
1222            )
1223        })?;
1224
1225        if name_pair.as_rule() != Rule::identifier {
1226            return Err(self.create_error_pair(
1227                SpecificError::UnexpectedRuleInParseScript(format!(
1228                    "Expected identifier, found {:?}",
1229                    name_pair.as_rule()
1230                )),
1231                &name_pair,
1232            ));
1233        }
1234
1235        let variable = Variable {
1236            name: self.to_node(&name_pair),
1237            is_mutable: mut_node,
1238        };
1239
1240        Ok(variable)
1241    }
1242
1243    fn parse_variable_item(&self, pair: &Pair<Rule>) -> Result<Variable, ParseError> {
1244        assert_eq!(pair.as_rule(), Rule::variable_item);
1245        let mut inner = pair.clone().into_inner();
1246        self.parse_maybe_mut_identifier(&inner.next().unwrap())
1247    }
1248
1249    fn parse_assignment_expression(&self, pair: &Pair<Rule>) -> Result<Expression, ParseError> {
1250        let mut iterator = pair.clone().into_inner();
1251        let lhs_logical =
1252            self.parse_logical(&iterator.next().expect("parse_assignment_expression"))?;
1253        if let Some(assignment_op_pair) = iterator.peek().clone() {
1254            iterator.next();
1255            let assignment_op = self.parse_assignment_op(&assignment_op_pair)?;
1256            let rhs_expr = self.parse_expression(&iterator.next().unwrap())?;
1257            let kind = match assignment_op {
1258                AssignmentOperatorKind::Assign => {
1259                    ExpressionKind::Assignment(Box::new(lhs_logical), Box::from(rhs_expr))
1260                }
1261                AssignmentOperatorKind::Compound(compound) => {
1262                    let op = CompoundOperator {
1263                        node: Self::node_ex(&assignment_op_pair),
1264                        kind: compound,
1265                    };
1266                    ExpressionKind::CompoundAssignment(
1267                        Box::from(lhs_logical),
1268                        op,
1269                        Box::from(rhs_expr),
1270                    )
1271                }
1272            };
1273
1274            Ok(self.create_expr(kind, &pair))
1275        } else {
1276            Ok(lhs_logical)
1277        }
1278    }
1279
1280    fn parse_assignment_op(&self, pair: &Pair<Rule>) -> Result<AssignmentOperatorKind, ParseError> {
1281        assert_eq!(pair.as_rule(), Rule::assign_op);
1282        let sub = Self::right_alternative(pair)?;
1283        let op = match sub.as_rule() {
1284            Rule::compound_assign_op => {
1285                AssignmentOperatorKind::Compound(Self::parse_compound_assign_op(&sub)?)
1286            }
1287            Rule::normal_assign_op => AssignmentOperatorKind::Assign,
1288            _ => {
1289                return Err(Self::to_err(
1290                    SpecificError::UnknownAssignmentOperator("strange".to_string()),
1291                    &sub,
1292                ));
1293            }
1294        };
1295
1296        Ok(op)
1297    }
1298
1299    #[allow(clippy::too_many_lines)]
1300    fn parse_destructuring_assignment(&self, pair: &Pair<Rule>) -> Result<Expression, ParseError> {
1301        assert_eq!(pair.as_rule(), Rule::destructuring_assignment);
1302        let mut inner = pair.clone().into_inner();
1303
1304        let var_list_pair = inner.next().ok_or_else(|| {
1305            self.create_error_pair(
1306                SpecificError::UnexpectedRuleInParseScript("missing variable_list".to_string()),
1307                pair,
1308            )
1309        })?;
1310
1311        let variables = self.parse_variable_list(&var_list_pair)?;
1312
1313        let rhs_pair = inner.next().ok_or_else(|| {
1314            self.create_error_pair(
1315                SpecificError::UnexpectedRuleInParseScript("missing RHS expression".to_string()),
1316                pair,
1317            )
1318        })?;
1319        let rhs_expr = self.parse_expression(&rhs_pair)?;
1320
1321        Ok(self.create_expr(
1322            ExpressionKind::DestructuringAssignment(variables, Box::new(rhs_expr)),
1323            &rhs_pair,
1324        ))
1325    }
1326
1327    fn right_alternative<'a>(pair: &Pair<'a, Rule>) -> Result<Pair<'a, Rule>, ParseError> {
1328        pair.clone()
1329            .into_inner()
1330            .next()
1331            .ok_or_else(|| Self::to_err(SpecificError::CouldNotMoveRight, &pair))
1332    }
1333
1334    pub fn parse_compound_assign_op(
1335        op_pair: &Pair<Rule>,
1336    ) -> Result<CompoundOperatorKind, ParseError> {
1337        assert_eq!(op_pair.as_rule(), Rule::compound_assign_op);
1338
1339        let kind = match Self::right_alternative(&op_pair)?.as_rule() {
1340            Rule::add_assign_op => CompoundOperatorKind::Add,
1341            Rule::sub_assign_op => CompoundOperatorKind::Sub,
1342            Rule::mul_assign_op => CompoundOperatorKind::Mul,
1343            Rule::div_assign_op => CompoundOperatorKind::Div,
1344            Rule::modulo_assign_op => CompoundOperatorKind::Modulo,
1345            _ => {
1346                return Err(Self::to_err(
1347                    SpecificError::UnknownOperator(format!(
1348                        "Found unexpected operator rule: {:?}",
1349                        op_pair.as_rule()
1350                    )),
1351                    &op_pair,
1352                ));
1353            }
1354        };
1355
1356        Ok(kind)
1357    }
1358
1359    #[allow(clippy::too_many_lines)]
1360    fn parse_variable_definition(&self, pair: &Pair<Rule>) -> Result<Expression, ParseError> {
1361        let mut inner = pair.clone().into_inner();
1362        let variable_item = Self::next_pair(&mut inner)?;
1363        let found_var = self.parse_variable_item(&variable_item)?;
1364
1365        let maybe_annotation = if let Some(peeked) = inner.peek() {
1366            if peeked.as_rule() == Rule::type_coerce {
1367                let type_coerce_pair = inner.next().unwrap();
1368                let mut type_inner = type_coerce_pair.clone().into_inner();
1369                let type_name_pair = type_inner.next().ok_or_else(|| {
1370                    self.create_error_pair(SpecificError::MissingTypeName, &type_coerce_pair)
1371                })?;
1372                Some(self.parse_type(type_name_pair)?)
1373            } else {
1374                None
1375            }
1376        } else {
1377            None
1378        };
1379
1380        let rhs_expr = self.parse_mutable_or_immutable_expression(&Self::next_pair(&mut inner)?)?;
1381
1382        if maybe_annotation.is_some() || found_var.is_mutable.is_some() {
1383            Ok(self.create_expr(
1384                ExpressionKind::VariableDefinition(
1385                    found_var,
1386                    maybe_annotation,
1387                    Box::from(rhs_expr),
1388                ),
1389                pair,
1390            ))
1391        } else {
1392            Ok(self.create_expr(
1393                ExpressionKind::VariableAssignment(found_var, Box::from(rhs_expr)),
1394                pair,
1395            ))
1396        }
1397    }
1398    fn parse_prefix(&self, pair: &Pair<Rule>) -> Result<Expression, ParseError> {
1399        assert_eq!(pair.as_rule(), Rule::prefix);
1400        let _span = pair.as_span();
1401        let inner = Self::convert_into_iterator(pair);
1402        let mut expr = None;
1403        let mut prefix_ops = Vec::new();
1404
1405        for part in inner {
1406            match part.as_rule() {
1407                Rule::prefix_op | Rule::op_neg | Rule::op_not => {
1408                    let op = self.parse_unary_operator(&part)?;
1409                    prefix_ops.push(op);
1410                }
1411                _ => {
1412                    expr = Some(self.parse_postfix_expression(&part)?);
1413                    break;
1414                }
1415            }
1416        }
1417
1418        let mut final_expr = expr.ok_or_else(|| {
1419            self.create_error_pair(SpecificError::ExpectedExpressionAfterPrefixOperator, pair)
1420        })?;
1421
1422        for op in prefix_ops.into_iter().rev() {
1423            final_expr = self.create_expr(ExpressionKind::UnaryOp(op, Box::new(final_expr)), pair);
1424        }
1425
1426        Ok(final_expr)
1427    }
1428
1429    fn parse_binary_operator(&self, pair: &Pair<Rule>) -> Result<BinaryOperator, ParseError> {
1430        let op = match pair.as_rule() {
1431            Rule::prefix_op => self.next_inner_pair(pair)?,
1432            _ => pair.clone(),
1433        };
1434
1435        let kind = match op.as_rule() {
1436            Rule::op_add => BinaryOperatorKind::Add,
1437            Rule::op_sub => BinaryOperatorKind::Subtract,
1438            Rule::op_mul => BinaryOperatorKind::Multiply,
1439            Rule::op_div => BinaryOperatorKind::Divide,
1440            Rule::op_mod => BinaryOperatorKind::Modulo,
1441            Rule::op_eq => BinaryOperatorKind::Equal,
1442            Rule::op_neq => BinaryOperatorKind::NotEqual,
1443            Rule::op_lt => BinaryOperatorKind::LessThan,
1444            Rule::op_lte => BinaryOperatorKind::LessEqual,
1445            Rule::op_gt => BinaryOperatorKind::GreaterThan,
1446            Rule::op_gte => BinaryOperatorKind::GreaterEqual,
1447            Rule::op_and => BinaryOperatorKind::LogicalAnd,
1448            Rule::op_or => BinaryOperatorKind::LogicalOr,
1449            _ => {
1450                panic!("unknown operator")
1451            }
1452        };
1453
1454        Ok(BinaryOperator {
1455            kind,
1456            node: self.to_node(pair),
1457        })
1458    }
1459
1460    fn parse_unary_operator(&self, pair: &Pair<Rule>) -> Result<UnaryOperator, ParseError> {
1461        let op = match pair.as_rule() {
1462            Rule::prefix_op => &self.next_inner_pair(pair)?,
1463            _ => pair,
1464        };
1465
1466        let node = self.to_node(op);
1467        match op.as_rule() {
1468            Rule::op_neg => Ok(UnaryOperator::Negate(node)),
1469            Rule::op_not => Ok(UnaryOperator::Not(node)),
1470            _ => Err(self.create_error_pair(
1471                SpecificError::UnexpectedUnaryOperator(Self::pair_to_rule(op)),
1472                op,
1473            )),
1474        }
1475    }
1476
1477    fn parse_module_segments(&self, pair: Pair<Rule>) -> Vec<Node> {
1478        pair.into_inner()
1479            .filter_map(|segment| {
1480                if segment.as_rule() == Rule::identifier {
1481                    Some(self.to_node(&segment))
1482                } else {
1483                    None
1484                }
1485            })
1486            .collect()
1487    }
1488
1489    fn parse_qualified_type_identifier(
1490        &self,
1491        pair: &Pair<Rule>,
1492    ) -> Result<QualifiedTypeIdentifier, ParseError> {
1493        let mut inner_pairs = pair.clone().into_inner();
1494        let mut generic_types = Vec::new();
1495
1496        let first = inner_pairs.next().ok_or_else(|| {
1497            self.create_error_pair(
1498                SpecificError::ExpectedTypeIdentifier(Self::pair_to_rule(pair)),
1499                pair,
1500            )
1501        })?;
1502
1503        match first.as_rule() {
1504            Rule::module_segments => {
1505                let module_path = self.parse_module_segments(first.clone());
1506                let type_id = inner_pairs.next().ok_or_else(|| {
1507                    self.create_error_pair(SpecificError::ExpectedTypeIdentifierAfterPath, &first)
1508                })?;
1509
1510                let type_identifier = self.parse_local_type_identifier(&type_id)?;
1511
1512                // TODO: Maybe loop and check for generic params
1513                if let Some(generic_params) = inner_pairs.next() {
1514                    if generic_params.as_rule() == Rule::generic_params {
1515                        generic_types = self.parse_generic_params(&generic_params)?;
1516                    }
1517                }
1518
1519                Ok(QualifiedTypeIdentifier::new_with_generics(
1520                    type_identifier,
1521                    module_path,
1522                    generic_types,
1523                ))
1524            }
1525            Rule::type_identifier => {
1526                let type_identifier = LocalTypeIdentifier(self.to_node(&first));
1527
1528                // TODO: Maybe loop and check for generic params
1529                if let Some(generic_params) = inner_pairs.next() {
1530                    if generic_params.as_rule() == Rule::generic_params {
1531                        generic_types = self.parse_generic_params(&generic_params)?;
1532                    }
1533                }
1534
1535                Ok(QualifiedTypeIdentifier::new_with_generics(
1536                    type_identifier,
1537                    Vec::new(),
1538                    generic_types,
1539                ))
1540            }
1541            _ => Err(self.create_error_pair(
1542                SpecificError::ExpectedTypeIdentifier(Self::pair_to_rule(&first)),
1543                &first,
1544            )),
1545        }
1546    }
1547
1548    fn parse_qualified_identifier(
1549        &self,
1550        pair: &Pair<Rule>,
1551    ) -> Result<QualifiedIdentifier, ParseError> {
1552        let mut inner_pairs = pair.clone().into_inner();
1553        let mut generic_types = Vec::new();
1554
1555        let first = inner_pairs
1556            .next()
1557            .ok_or_else(|| self.create_error_pair(SpecificError::ExpectedIdentifier, pair))?;
1558
1559        match first.as_rule() {
1560            Rule::module_segments => {
1561                let module_path = self.parse_module_segments(first.clone());
1562                let id = inner_pairs.next().ok_or_else(|| {
1563                    self.create_error_pair(SpecificError::ExpectedIdentifierAfterPath, &first)
1564                })?;
1565
1566                let identifier = self.to_node(&id);
1567
1568                // TODO: Maybe loop and check for generic params
1569                if let Some(generic_params) = inner_pairs.next() {
1570                    if generic_params.as_rule() == Rule::generic_params {
1571                        generic_types = self.parse_generic_params(&generic_params)?;
1572                    }
1573                }
1574
1575                Ok(QualifiedIdentifier::new_with_generics(
1576                    identifier,
1577                    module_path,
1578                    generic_types,
1579                ))
1580            }
1581            Rule::identifier => {
1582                let type_identifier = self.to_node(&first);
1583
1584                // TODO: Maybe loop and check for generic params
1585                if let Some(generic_params) = inner_pairs.next() {
1586                    if generic_params.as_rule() == Rule::generic_params {
1587                        generic_types = self.parse_generic_params(&generic_params)?;
1588                    }
1589                }
1590
1591                Ok(QualifiedIdentifier::new_with_generics(
1592                    type_identifier,
1593                    Vec::new(),
1594                    generic_types,
1595                ))
1596            }
1597            _ => Err(self.create_error_pair(SpecificError::ExpectedIdentifier, &first)),
1598        }
1599    }
1600
1601    fn parse_qualified_identifier_expression(
1602        &self,
1603        pair: &Pair<Rule>,
1604    ) -> Result<Expression, ParseError> {
1605        let qualified_identifier = self.parse_qualified_identifier(pair)?;
1606        Ok(self.create_expr(
1607            ExpressionKind::IdentifierReference(qualified_identifier),
1608            pair,
1609        ))
1610    }
1611
1612    fn parse_generic_params(&self, pair: &Pair<Rule>) -> Result<Vec<Type>, ParseError> {
1613        let inner_pairs = pair.clone().into_inner();
1614        let mut generic_types = Vec::new();
1615
1616        for type_pair in inner_pairs {
1617            if type_pair.as_rule() == Rule::type_name {
1618                generic_types.push(self.parse_type(type_pair)?);
1619            }
1620        }
1621
1622        Ok(generic_types)
1623    }
1624
1625    fn parse_local_type_identifier_node(&self, pair: &Pair<Rule>) -> Result<Node, ParseError> {
1626        if pair.as_rule() != Rule::type_identifier {
1627            return Err(self.create_error_pair(
1628                SpecificError::ExpectedTypeIdentifier(format!("{:?}", pair.as_rule())),
1629                pair,
1630            ));
1631        }
1632        Ok(self.to_node(pair))
1633    }
1634
1635    fn parse_generic_type_variables(
1636        &self,
1637        pair: &Pair<Rule>,
1638    ) -> Result<Vec<TypeVariable>, ParseError> {
1639        assert_eq!(pair.as_rule(), Rule::generic_type_params);
1640        let mut type_params = Vec::new();
1641        for type_identifier_pair in Self::convert_into_iterator(pair) {
1642            if type_identifier_pair.as_rule() == Rule::type_identifier {
1643                type_params.push(TypeVariable(
1644                    self.parse_local_type_identifier_node(&type_identifier_pair)?,
1645                ));
1646            } else {
1647                panic!("internal error generic type params")
1648            }
1649        }
1650        Ok(type_params)
1651    }
1652
1653    fn parse_local_type_identifier_with_optional_type_variables(
1654        &self,
1655        pair: &Pair<Rule>,
1656    ) -> Result<LocalTypeIdentifierWithOptionalTypeVariables, ParseError> {
1657        assert_eq!(pair.as_rule(), Rule::type_identifier_optional_type_params);
1658
1659        let mut inner = pair.clone().into_inner();
1660        let name = self.expect_local_type_identifier_next(&mut inner)?;
1661
1662        let type_variables = if let Some(generic_params_pair) = inner.peek() {
1663            // Peek to see if generic params exist
1664            if generic_params_pair.as_rule() == Rule::generic_type_params {
1665                let generic_params_pair = inner.next().unwrap(); // Consume the generic_type_params pair
1666                self.parse_generic_type_variables(&generic_params_pair)?
1667            } else {
1668                Vec::new()
1669            }
1670        } else {
1671            Vec::new()
1672        };
1673
1674        Ok(LocalTypeIdentifierWithOptionalTypeVariables {
1675            name: name.0,
1676            type_variables,
1677        })
1678    }
1679
1680    fn parse_struct_fields_expressions<'a>(
1681        &self,
1682        field_list_pair: &Pair<Rule>,
1683    ) -> Result<(Vec<FieldExpression>, bool), ParseError> {
1684        let mut fields = Vec::new();
1685        let mut has_rest = false;
1686
1687        for field_pair in field_list_pair.clone().into_inner() {
1688            match field_pair.as_rule() {
1689                Rule::struct_field => {
1690                    let mut field_inner = field_pair.into_inner();
1691                    let ident = self.expect_field_label_next(&mut field_inner)?;
1692                    let field_name = FieldName(ident.0);
1693                    let field_value = self.parse_expression(&field_inner.next().unwrap())?;
1694
1695                    fields.push(FieldExpression {
1696                        field_name,
1697                        expression: field_value,
1698                    });
1699                }
1700                Rule::rest_fields => {
1701                    has_rest = true;
1702                }
1703                _ => {
1704                    return Err(
1705                        self.create_error_pair(SpecificError::ExpectedFieldOrRest, &field_pair)
1706                    );
1707                }
1708            }
1709        }
1710
1711        Ok((fields, has_rest))
1712    }
1713
1714    fn parse_anonymous_struct_literal(&self, pair: &Pair<Rule>) -> Result<Expression, ParseError> {
1715        let (fields, has_rest) = self.parse_anonymous_struct_literal_fields(&pair)?;
1716        Ok(self.create_expr(
1717            ExpressionKind::AnonymousStructLiteral(fields, has_rest),
1718            pair,
1719        ))
1720    }
1721
1722    fn parse_anonymous_struct_literal_fields(
1723        &self,
1724        pair: &Pair<Rule>,
1725    ) -> Result<(Vec<FieldExpression>, bool), ParseError> {
1726        assert_eq!(pair.as_rule(), Rule::anonymous_struct_literal);
1727        let mut inner = Self::convert_into_iterator(pair);
1728        let (field_expressions, detected_rest) =
1729            self.parse_struct_fields_expressions(&inner.next().unwrap())?;
1730
1731        Ok((field_expressions, detected_rest))
1732    }
1733
1734    fn parse_struct_literal_optional_fields(
1735        &self,
1736        pair: &Pair<Rule>,
1737    ) -> Result<(Vec<FieldExpression>, bool), ParseError> {
1738        assert_eq!(pair.as_rule(), Rule::struct_literal_optional_field_list);
1739        let mut inner = Self::convert_into_iterator(pair);
1740        let (field_expressions, detected_rest) = if let Some(field_list) = inner.next() {
1741            self.parse_struct_fields_expressions(&field_list)?
1742        } else {
1743            (vec![], false)
1744        };
1745
1746        Ok((field_expressions, detected_rest))
1747    }
1748
1749    fn parse_struct_literal(&self, pair: &Pair<Rule>) -> Result<Expression, ParseError> {
1750        let mut inner = Self::convert_into_iterator(pair);
1751
1752        let type_pair = inner.next().unwrap();
1753
1754        let struct_name = self.parse_qualified_type_identifier(&type_pair)?;
1755
1756        let anon_fields = inner.next().unwrap();
1757
1758        let (fields, has_rest) = self.parse_struct_literal_optional_fields(&anon_fields)?;
1759
1760        Ok(self.create_expr(
1761            ExpressionKind::NamedStructLiteral(struct_name, fields, has_rest),
1762            pair,
1763        ))
1764    }
1765
1766    fn parse_static_member_reference(&self, pair: &Pair<Rule>) -> Result<Expression, ParseError> {
1767        let mut inner = pair.clone().into_inner();
1768
1769        let type_identifier = self.parse_qualified_type_identifier(&inner.next().unwrap())?;
1770        let member_name = self.expect_identifier_next(&mut inner)?;
1771
1772        Ok(self.create_expr(
1773            ExpressionKind::StaticMemberFunctionReference(type_identifier, member_name.0),
1774            pair,
1775        ))
1776    }
1777
1778    fn parse_constant_reference(&self, pair: &Pair<Rule>) -> Result<Expression, ParseError> {
1779        assert_eq!(pair.as_rule(), Rule::constant_reference);
1780        let mut inner_pairs = pair.clone().into_inner();
1781
1782        let mut first = inner_pairs.next().unwrap();
1783
1784        let module_path = if first.as_rule() == Rule::module_segments {
1785            let path = self.parse_module_segments(first.clone());
1786            first = inner_pairs.next().unwrap();
1787            Some(ModulePath(path))
1788        } else {
1789            None
1790        };
1791
1792        let identifier = QualifiedConstantIdentifier::new(self.to_node(&first), module_path);
1793
1794        Ok(self.create_expr(ExpressionKind::ConstantReference(identifier), pair))
1795    }
1796
1797    fn parse_term(&self, pair2: &Pair<Rule>) -> Result<Expression, ParseError> {
1798        assert_eq!(pair2.as_rule(), Rule::term);
1799        let sub = &Self::right_alternative(pair2)?;
1800        match sub.as_rule() {
1801            Rule::qualified_identifier => self.parse_qualified_identifier_expression(sub),
1802            Rule::static_member_reference => self.parse_static_member_reference(sub),
1803
1804            Rule::enum_literal => {
1805                Ok(self.create_expr(ExpressionKind::Literal(self.parse_enum_literal(sub)?), sub))
1806            }
1807            Rule::constant_reference => self.parse_constant_reference(sub),
1808            Rule::parenthesized => {
1809                let inner = self.next_inner_pair(sub)?;
1810                self.parse_expression(&inner)
1811            }
1812            Rule::basic_literal => {
1813                let (literal, node) = self.parse_basic_literal(sub)?;
1814                Ok(self.create_expr_span(ExpressionKind::Literal(literal), node))
1815            }
1816            Rule::struct_literal => self.parse_struct_literal(sub),
1817            Rule::anonymous_struct_literal => self.parse_anonymous_struct_literal(sub),
1818
1819            Rule::interpolated_string => self.parse_interpolated_string(sub),
1820
1821            _ => {
1822                Err(self
1823                    .create_error_pair(SpecificError::UnknownTerm(Self::pair_to_rule(sub)), sub))
1824            }
1825        }
1826    }
1827
1828    fn parse_interpolated_string(&self, pair: &Pair<Rule>) -> Result<Expression, ParseError> {
1829        let mut parts = Vec::new();
1830
1831        for part_pair in Self::convert_into_iterator(pair) {
1832            match part_pair.as_rule() {
1833                Rule::text => {
1834                    parts.push(StringPart::Literal(
1835                        self.to_node(&part_pair),
1836                        self.unescape_string(&part_pair, false)?,
1837                    ));
1838                }
1839                Rule::interpolation => {
1840                    let inner = self.next_inner_pair(&part_pair.clone())?;
1841                    let expr = match inner.as_rule() {
1842                        Rule::expression => self.parse_expression(&inner)?,
1843                        _ => {
1844                            return Err(self.create_error_pair(
1845                                SpecificError::ExpectedExpressionInInterpolation,
1846                                &inner,
1847                            ));
1848                        }
1849                    };
1850
1851                    let format = match Self::convert_into_iterator(&part_pair).nth(1) {
1852                        Some(fmt) => {
1853                            if fmt.as_rule() == Rule::format_specifier {
1854                                Some(self.parse_format_specifier(&fmt)?)
1855                            } else {
1856                                None
1857                            }
1858                        }
1859                        _ => None,
1860                    };
1861
1862                    parts.push(StringPart::Interpolation(Box::new(expr), format));
1863                }
1864                _ => {
1865                    return Err(self.create_error_pair(
1866                        SpecificError::UnexpectedRuleInInterpolation,
1867                        &part_pair,
1868                    ));
1869                }
1870            }
1871        }
1872
1873        Ok(self.create_expr(ExpressionKind::InterpolatedString(parts), pair))
1874    }
1875
1876    fn parse_format_specifier(&self, pair: &Pair<Rule>) -> Result<FormatSpecifier, ParseError> {
1877        let node = self.to_node(pair);
1878        match pair.as_str() {
1879            "x" => Ok(FormatSpecifier::LowerHex(node)),
1880            "X" => Ok(FormatSpecifier::UpperHex(node)),
1881            "b" => Ok(FormatSpecifier::Binary(node)),
1882            "f" => Ok(FormatSpecifier::Float(node)),
1883            s if s.starts_with("..") => {
1884                let precision: u32 = s[2..s.len() - 1].parse().map_err(|_| {
1885                    self.create_error_pair(SpecificError::InvalidPrecisionValue, pair)
1886                })?;
1887                let typ = match s.chars().last().unwrap() {
1888                    'f' => PrecisionType::Float(node),
1889                    's' => PrecisionType::String(node),
1890                    _ => {
1891                        return Err(
1892                            self.create_error_pair(SpecificError::InvalidPrecisionType, pair)
1893                        )?;
1894                    }
1895                };
1896                Ok(FormatSpecifier::Precision(
1897                    precision,
1898                    self.to_node(&pair),
1899                    typ,
1900                ))
1901            }
1902            _ => Err(self.create_error_pair(SpecificError::InvalidFormatSpecifier, pair)),
1903        }
1904    }
1905
1906    fn parse_enum_literal(&self, pair: &Pair<Rule>) -> Result<LiteralKind, ParseError> {
1907        let mut inner = Self::convert_into_iterator(pair);
1908
1909        // Parse enum type name
1910        let enum_type = self.parse_qualified_type_identifier(&inner.next().unwrap())?;
1911
1912        // Parse variant name
1913        let variant_pair = Self::expect_next(&mut inner, Rule::type_identifier)?;
1914        let variant_type_identifier = LocalTypeIdentifier::new(self.to_node(&variant_pair));
1915
1916        // Parse fields if they exist
1917        let enum_variant_literal = match inner.next() {
1918            Some(fields_pair) => match fields_pair.as_rule() {
1919                Rule::struct_literal_optional_field_list => {
1920                    let (field_expressions, detected_rest) =
1921                        self.parse_struct_literal_optional_fields(&fields_pair)?;
1922                    EnumVariantLiteral::Struct(
1923                        enum_type,
1924                        variant_type_identifier,
1925                        field_expressions,
1926                        detected_rest,
1927                    )
1928                }
1929                Rule::tuple_fields => {
1930                    let mut expressions = vec![];
1931                    for field in Self::convert_into_iterator(&fields_pair) {
1932                        let field_value = self.parse_expression(&field)?;
1933                        expressions.push(field_value);
1934                    }
1935                    EnumVariantLiteral::Tuple(enum_type, variant_type_identifier, expressions)
1936                }
1937                _ => {
1938                    error!("{:?}, {}", fields_pair.as_rule(), "strange");
1939                    return Err(
1940                        self.create_error_pair(SpecificError::UnexpectedVariantField, &fields_pair)
1941                    );
1942                }
1943            },
1944            _ => EnumVariantLiteral::Simple(enum_type, variant_type_identifier),
1945        };
1946
1947        Ok(LiteralKind::EnumVariant(enum_variant_literal))
1948    }
1949
1950    fn unescape_unicode(
1951        &self,
1952        chars: &mut Peekable<Chars>,
1953        octets: &mut Vec<u8>,
1954        pair: &Pair<Rule>,
1955    ) -> Result<(), ParseError> {
1956        match chars.next() {
1957            Some('(') => {
1958                let mut hex_digits = String::new();
1959
1960                while let Some(&c) = chars.peek() {
1961                    if c == ')' {
1962                        break;
1963                    }
1964                    if c.is_ascii_hexdigit() && hex_digits.len() < 6 {
1965                        hex_digits.push(c);
1966                        chars.next();
1967                    } else {
1968                        return Err(
1969                            self.create_error_pair(SpecificError::InvalidUnicodeEscape, pair)
1970                        );
1971                    }
1972                }
1973
1974                match chars.next() {
1975                    Some(')') => {
1976                        if hex_digits.is_empty() {
1977                            return Err(
1978                                self.create_error_pair(SpecificError::InvalidUnicodeEscape, pair)
1979                            );
1980                        }
1981
1982                        let code = u32::from_str_radix(&hex_digits, 16).map_err(|_| {
1983                            self.create_error_pair(SpecificError::InvalidUnicodeEscape, pair)
1984                        })?;
1985
1986                        if code > 0x0010_FFFF {
1987                            return Err(
1988                                self.create_error_pair(SpecificError::InvalidUnicodeEscape, pair)
1989                            );
1990                        }
1991
1992                        if let Some(c) = std::char::from_u32(code) {
1993                            let mut buf = [0; 4];
1994                            let encoded = c.encode_utf8(&mut buf);
1995                            octets.extend_from_slice(encoded.as_bytes());
1996                        } else {
1997                            return Err(
1998                                self.create_error_pair(SpecificError::InvalidUnicodeEscape, pair)
1999                            );
2000                        }
2001                    }
2002                    _ => {
2003                        return Err(
2004                            self.create_error_pair(SpecificError::InvalidUnicodeEscape, pair)
2005                        );
2006                    }
2007                }
2008            }
2009            _ => {
2010                return Err(self.create_error_pair(SpecificError::InvalidUnicodeEscape, pair));
2011            }
2012        }
2013        Ok(())
2014    }
2015
2016    fn unescape_hex(
2017        &self,
2018        chars: &mut Peekable<Chars>,
2019        pair: &Pair<Rule>,
2020    ) -> Result<u8, ParseError> {
2021        let mut hex_digits = String::new();
2022        for _ in 0..2 {
2023            match chars.next() {
2024                Some(h) if h.is_ascii_hexdigit() => {
2025                    hex_digits.push(h);
2026                }
2027                _ => {
2028                    return Err(self.create_error_pair(SpecificError::InvalidHexEscape, pair));
2029                }
2030            }
2031        }
2032        u8::from_str_radix(&hex_digits, 16)
2033            .map_err(|_| self.create_error_pair(SpecificError::InvalidHexEscape, pair))
2034    }
2035
2036    fn unescape_string(&self, pair: &Pair<Rule>, is_literal: bool) -> Result<String, ParseError> {
2037        let mut octets = Vec::new();
2038
2039        let raw = if is_literal {
2040            &pair.as_str()[1..pair.as_str().len() - 1]
2041        } else {
2042            pair.as_str()
2043        };
2044
2045        let mut chars = raw.chars().peekable();
2046
2047        while let Some(ch) = chars.next() {
2048            if ch == '\\' {
2049                let Some(next_ch) = chars.next() else {
2050                    return Err(
2051                        self.create_error_pair(SpecificError::UnfinishedEscapeSequence, pair)
2052                    );
2053                };
2054                match next_ch {
2055                    'n' => {
2056                        octets.push(b'\n');
2057                    }
2058                    't' => {
2059                        octets.push(b'\t');
2060                    }
2061                    '\\' => {
2062                        octets.push(b'\\');
2063                    }
2064                    '"' => {
2065                        octets.push(b'"');
2066                    }
2067                    '\'' => {
2068                        octets.push(b'\'');
2069                    }
2070                    // Two hexadecimal digits that result in an `u8`
2071                    'x' => {
2072                        let code = self.unescape_hex(&mut chars, pair)?;
2073                        octets.push(code);
2074                    }
2075                    // Unicode character
2076                    'u' => {
2077                        self.unescape_unicode(&mut chars, &mut octets, pair)?;
2078                    }
2079
2080                    other => {
2081                        return Err(self.create_error_pair(
2082                            SpecificError::UnknownEscapeCharacter(other),
2083                            pair,
2084                        ));
2085                    }
2086                }
2087            } else {
2088                let mut buf = [0; 4];
2089                let utf8_bytes = ch.encode_utf8(&mut buf);
2090                octets.extend_from_slice(utf8_bytes.as_bytes());
2091            }
2092        }
2093
2094        let output = String::from_utf8(octets)
2095            .map_err(|_| self.create_error_pair(SpecificError::InvalidUtf8Sequence, pair))?;
2096
2097        Ok(output)
2098    }
2099
2100    fn parse_basic_literal(&self, pair: &Pair<Rule>) -> Result<(LiteralKind, Node), ParseError> {
2101        assert_eq!(pair.as_rule(), Rule::basic_literal);
2102        let inner = self.next_inner_pair(pair)?;
2103        let literal_kind = match inner.as_rule() {
2104            Rule::int_lit => LiteralKind::Int,
2105            Rule::float_lit => LiteralKind::Float,
2106            Rule::string_lit => {
2107                let processed_string = self.unescape_string(&inner, true)?;
2108                LiteralKind::String(processed_string)
2109            }
2110            Rule::bool_lit => LiteralKind::Bool,
2111            Rule::none_lit => LiteralKind::None,
2112            Rule::tuple_lit => {
2113                let mut expressions = Vec::new();
2114                for expr_pair in Self::convert_into_iterator(&inner) {
2115                    expressions.push(self.parse_expression(&expr_pair)?);
2116                }
2117                LiteralKind::Tuple(expressions)
2118            }
2119            _ => return Err(self.create_error_pair(SpecificError::UnknownLiteral, &inner)),
2120        };
2121        Ok((literal_kind, self.to_node(&inner)))
2122    }
2123
2124    fn parse_array_literal(&self, pair: &Pair<Rule>) -> Result<Expression, ParseError> {
2125        let mut elements = Vec::new();
2126        for element in Self::convert_into_iterator(pair) {
2127            elements.push(self.parse_expression(&element)?);
2128        }
2129        Ok(self.create_expr(ExpressionKind::Literal(LiteralKind::Slice(elements)), pair))
2130    }
2131
2132    fn parse_map_literal(&self, pair: &Pair<Rule>) -> Result<Expression, ParseError> {
2133        let mut entries = Vec::new();
2134
2135        for entry_pair in Self::convert_into_iterator(pair) {
2136            if entry_pair.as_rule() == Rule::map_entry {
2137                let mut entry_inner = Self::convert_into_iterator(&entry_pair);
2138                let key = self.parse_expression(&Self::next_pair(&mut entry_inner)?)?;
2139                let value = self.parse_expression(&Self::next_pair(&mut entry_inner)?)?;
2140                entries.push((key, value));
2141            }
2142        }
2143
2144        Ok(self.create_expr(
2145            ExpressionKind::Literal(LiteralKind::SlicePair(entries)),
2146            pair,
2147        ))
2148    }
2149
2150    fn parse_mutable_or_immutable_expression(
2151        &self,
2152        pair: &Pair<Rule>,
2153    ) -> Result<MutableOrImmutableExpression, ParseError> {
2154        // The mut_expression rule is defined as { lvalue | expression }.
2155        // Its inner pair will be one of those alternatives.
2156        let mut inner = pair.clone().into_inner();
2157        let first = Self::next_pair(&mut inner)?;
2158        match first.as_rule() {
2159            Rule::lvalue => {
2160                let mut lvalue_inner = first.into_inner();
2161                let mut_kw = Self::next_pair(&mut lvalue_inner)?;
2162                let postfix = Self::next_pair(&mut lvalue_inner)?;
2163                let expr = self.parse_postfix_expression(&postfix)?;
2164                Ok(MutableOrImmutableExpression {
2165                    is_mutable: Some(self.to_node(&mut_kw)),
2166                    expression: expr,
2167                })
2168            }
2169            Rule::expression => {
2170                // Otherwise, if it’s an expression, parse it normally.
2171                let expr = self.parse_expression(&first)?;
2172                Ok(MutableOrImmutableExpression {
2173                    is_mutable: None,
2174                    expression: expr,
2175                })
2176            }
2177            _ => {
2178                Err(self
2179                    .create_error_pair(SpecificError::UnexpectedTokenInMutableExpression, &first))
2180            }
2181        }
2182    }
2183
2184    fn parse_function_call_postfix(
2185        &self,
2186        pair: &Pair<Rule>,
2187    ) -> Result<Vec<MutableOrImmutableExpression>, ParseError> {
2188        assert_eq!(pair.as_rule(), Rule::function_call_postfix);
2189        let mut inner = pair.clone().into_inner();
2190        self.parse_function_call_arguments(&Self::next_pair(&mut inner)?)
2191    }
2192
2193    fn parse_function_call_arguments(
2194        &self,
2195        pair: &Pair<Rule>,
2196    ) -> Result<Vec<MutableOrImmutableExpression>, ParseError> {
2197        assert_eq!(pair.as_rule(), Rule::function_call_args);
2198        let inner = pair.clone().into_inner();
2199        let mut args = Vec::new();
2200
2201        // Parse arguments
2202        for arg_pair in inner {
2203            if arg_pair.as_rule() == Rule::mut_expression {
2204                //let mut arg_inner = Self::convert_into_iterator(&arg_pair).peekable();
2205
2206                let expr = self.parse_mutable_or_immutable_expression(&arg_pair)?;
2207                args.push(expr);
2208            } else {
2209                return Err(
2210                    self.create_error_pair(SpecificError::UnexpectedTokenInFunctionCall, &arg_pair)
2211                );
2212            }
2213        }
2214
2215        Ok(args)
2216    }
2217
2218    #[allow(clippy::too_many_lines)]
2219    fn parse_type(&self, pair: Pair<Rule>) -> Result<Type, ParseError> {
2220        match pair.as_rule() {
2221            Rule::type_name => {
2222                let mut inner = pair.clone().into_inner();
2223                let base_type = if let Some(inner_pair) = inner.next() {
2224                    self.parse_type(inner_pair)?
2225                } else {
2226                    panic!("shouldn't get to here")
2227                };
2228
2229                let optional_marker = inner
2230                    .find(|p| p.as_rule() == Rule::optional_marker)
2231                    .map(|marker_pair| self.to_node(&marker_pair));
2232                if let Some(found_optional_marker) = optional_marker {
2233                    Ok(Type::Optional(Box::new(base_type), found_optional_marker))
2234                } else {
2235                    Ok(base_type)
2236                }
2237            }
2238
2239            Rule::base_type => {
2240                let mut inner = pair.into_inner();
2241                let first = inner.next().unwrap();
2242                let base_type = self.parse_type(first)?;
2243
2244                Ok(base_type)
2245            }
2246            Rule::function_type => {
2247                let mut function_inner = pair.into_inner();
2248
2249                // Parse parameter types
2250                let param_types = if let Some(params) = function_inner
2251                    .next()
2252                    .filter(|p| p.as_rule() == Rule::function_params)
2253                {
2254                    params
2255                        .into_inner()
2256                        .map(|param| {
2257                            Ok(TypeForParameter {
2258                                ast_type: self.parse_type(param).unwrap(),
2259                                is_mutable: false,
2260                            })
2261                        })
2262                        .collect::<Result<Vec<_>, ParseError>>()?
2263                } else {
2264                    Vec::new()
2265                };
2266
2267                // Parse return type
2268                let return_type = self.parse_type(function_inner.next().unwrap())?;
2269
2270                Ok(Type::Function(param_types, Box::new(return_type)))
2271            }
2272
2273            Rule::qualified_type_identifier => {
2274                let qualified_id = self.parse_qualified_type_identifier(&pair)?;
2275                Ok(Type::Named(qualified_id))
2276            }
2277            Rule::tuple_type => {
2278                let elements = self.parse_tuple_type_elements(&pair)?;
2279                Ok(Type::Tuple(elements))
2280            }
2281            Rule::slice_pair_type => {
2282                let mut inner = pair.into_inner();
2283                let key_type = self.parse_type(Self::next_pair(&mut inner)?)?;
2284                let value_type = self.parse_type(Self::next_pair(&mut inner)?)?;
2285                Ok(Type::SlicePair(Box::new(key_type), Box::new(value_type)))
2286            }
2287
2288            Rule::slice_type => {
2289                let inner = self.next_inner_pair(&pair)?;
2290                let element_type = self.parse_type(inner)?;
2291                Ok(Type::Slice(Box::new(element_type)))
2292            }
2293
2294            Rule::struct_type => {
2295                let element_type = self.parse_struct_type(&pair)?;
2296                Ok(Type::AnonymousStruct(element_type))
2297            }
2298
2299            _ => Err(self.create_error_pair(SpecificError::UnexpectedTypeRule, &pair)),
2300        }
2301    }
2302
2303    #[allow(unused)] // TODO: Use this again
2304    fn parse_local_type_identifier(
2305        &self,
2306        pair: &Pair<Rule>,
2307    ) -> Result<LocalTypeIdentifier, ParseError> {
2308        if pair.as_rule() != Rule::type_identifier {
2309            return Err(self.create_error_pair(
2310                SpecificError::ExpectedTypeIdentifier(format!("{:?}", pair.as_rule())),
2311                pair,
2312            ));
2313        }
2314        Ok(LocalTypeIdentifier::new(self.to_node(pair)))
2315    }
2316
2317    fn parse_local_type_identifier_next<'a>(
2318        &self,
2319        pairs: &mut impl Iterator<Item = Pair<'a, Rule>>,
2320    ) -> Result<LocalTypeIdentifier, ParseError> {
2321        let pair = Self::next_pair(pairs)?;
2322        if pair.as_rule() != Rule::type_identifier {
2323            return Err(self.create_error_pair(
2324                SpecificError::ExpectedLocalTypeIdentifier(Self::pair_to_rule(&pair)),
2325                &pair,
2326            ));
2327        }
2328        Ok(LocalTypeIdentifier::new(self.to_node(&pair)))
2329    }
2330
2331    fn parse_enum_def(&self, pair: &Pair<Rule>) -> Result<Definition, ParseError> {
2332        let mut inner = Self::convert_into_iterator(pair);
2333
2334        let name_with_optional_type_params =
2335            self.parse_local_type_identifier_with_optional_type_variables(&inner.next().unwrap())?;
2336
2337        let mut variants = Vec::new();
2338
2339        if let Some(variants_pair) = inner.next() {
2340            if variants_pair.as_rule() == Rule::enum_variants {
2341                for variant_pair in Self::convert_into_iterator(&variants_pair) {
2342                    if variant_pair.as_rule() == Rule::enum_variant {
2343                        let variant =
2344                            self.parse_enum_variant(&self.next_inner_pair(&variant_pair)?)?;
2345
2346                        variants.push(variant);
2347                    }
2348                }
2349            }
2350        }
2351
2352        Ok(Definition::EnumDef(
2353            name_with_optional_type_params,
2354            variants,
2355        ))
2356    }
2357
2358    fn parse_enum_variant(&self, pair: &Pair<Rule>) -> Result<EnumVariantType, ParseError> {
2359        let enum_variant = match pair.as_rule() {
2360            Rule::simple_variant => EnumVariantType::Simple(self.to_node(pair)),
2361            Rule::tuple_variant => {
2362                let mut inner = Self::convert_into_iterator(pair);
2363                let name = self.expect_local_type_identifier_next(&mut inner)?;
2364
2365                let tuple_elements = self.parse_tuple_type_elements(&inner.next().unwrap())?;
2366
2367                EnumVariantType::Tuple(name.0, tuple_elements)
2368            }
2369            Rule::struct_variant => {
2370                let mut inner = Self::convert_into_iterator(pair);
2371                let name = self.expect_local_type_identifier_next(&mut inner)?;
2372
2373                let struct_type = self.parse_struct_type(&inner.next().unwrap())?;
2374                EnumVariantType::Struct(name.0, struct_type)
2375            }
2376            _ => {
2377                return Err(self.create_error_pair(
2378                    SpecificError::UnknownEnumVariant(Self::pair_to_rule(pair)),
2379                    pair,
2380                ));
2381            }
2382        };
2383
2384        Ok(enum_variant)
2385    }
2386
2387    fn parse_match_expr(&self, pair: &Pair<Rule>) -> Result<Expression, ParseError> {
2388        let mut inner = Self::convert_into_iterator(pair);
2389        let value = self.parse_mutable_or_immutable_expression(&Self::next_pair(&mut inner)?)?;
2390        let arms_pair = Self::next_pair(&mut inner)?;
2391        let mut arms = Vec::new();
2392
2393        for arm_pair in Self::convert_into_iterator(&arms_pair) {
2394            if arm_pair.as_rule() == Rule::match_arm {
2395                let mut arm_inner = Self::convert_into_iterator(&arm_pair);
2396                let pattern = self.parse_match_pattern(&Self::next_pair(&mut arm_inner)?)?;
2397
2398                // Handle both block and direct expression cases
2399                let expr = match Self::next_pair(&mut arm_inner)? {
2400                    block if block.as_rule() == Rule::block => self.parse_block(&block)?,
2401                    expr => self.parse_expression(&expr)?,
2402                };
2403
2404                arms.push(MatchArm {
2405                    pattern,
2406                    expression: expr,
2407                });
2408            }
2409        }
2410
2411        if arms.is_empty() {
2412            return Err(self.create_error_pair(SpecificError::MustHaveAtLeastOneArm, pair));
2413        }
2414
2415        Ok(self.create_expr(ExpressionKind::Match(Box::new(value), arms), pair))
2416    }
2417
2418    fn parse_match_pattern(&self, pair: &Pair<Rule>) -> Result<Pattern, ParseError> {
2419        let mut inner = Self::convert_into_iterator(pair);
2420        let pattern_inside = inner.next().expect("should have inner");
2421        match pattern_inside.as_rule() {
2422            Rule::normal_pattern => {
2423                let (match_pattern, pattern_node) =
2424                    self.parse_normal_match_pattern(&pattern_inside)?;
2425                let inner_pairs: Vec<_> = pattern_inside.clone().into_inner().collect();
2426                let has_guard = inner_pairs
2427                    .get(1)
2428                    .map(|p| p.as_rule() == Rule::guard_clause)
2429                    .unwrap_or(false);
2430
2431                let guard_clause = if has_guard {
2432                    Some(self.parse_guard_clause(&inner_pairs[1])?)
2433                } else {
2434                    None
2435                };
2436                Ok(Pattern::NormalPattern(
2437                    pattern_node,
2438                    match_pattern,
2439                    guard_clause,
2440                ))
2441            }
2442            Rule::wildcard_pattern => Ok(Pattern::Wildcard(self.to_node(pair))),
2443            _ => Err(self.create_error_pair(SpecificError::MustHaveAtLeastOneArm, pair)),
2444        }
2445    }
2446
2447    fn parse_guard_clause(&self, pair: &Pair<Rule>) -> Result<GuardClause, ParseError> {
2448        let inner = Self::right_alternative(&pair)?;
2449        let clause = match inner.as_rule() {
2450            Rule::wildcard_pattern => GuardClause::Wildcard(Self::node_ex(&pair)),
2451            Rule::expression => {
2452                let mut iterator = inner.into_inner();
2453                let result = self.parse_expression(&Self::next_pair(&mut iterator)?)?;
2454                GuardClause::Expression(result)
2455            }
2456            _ => {
2457                return Err(Self::to_err(
2458                    SpecificError::UnknownExpr("guard_clause".to_string()),
2459                    &pair,
2460                ))?;
2461            }
2462        };
2463
2464        Ok(clause)
2465    }
2466
2467    fn parse_guard_expr_list(&self, pair: &Pair<Rule>) -> Result<Expression, ParseError> {
2468        let mut guard_exprs = Vec::new();
2469
2470        for expr_pair in Self::convert_into_iterator(pair) {
2471            match expr_pair.as_rule() {
2472                Rule::guard_item => {
2473                    let mut guard_inner = Self::convert_into_iterator(&expr_pair);
2474                    let guard_clause = Self::next_pair(&mut guard_inner)?;
2475                    let condition = self.parse_guard_clause(&guard_clause)?;
2476                    let result = self.parse_expression(&Self::next_pair(&mut guard_inner)?)?;
2477                    guard_exprs.push(GuardExpr {
2478                        clause: condition,
2479                        result,
2480                    });
2481                }
2482
2483                _ => {
2484                    panic!("Unexpected rule: {:?}", expr_pair.as_rule());
2485                }
2486            }
2487        }
2488
2489        Ok(self.create_expr(ExpressionKind::Guard(guard_exprs), pair))
2490    }
2491
2492    fn parse_normal_match_pattern(
2493        &self,
2494        pair: &Pair<Rule>,
2495    ) -> Result<(NormalPattern, Node), ParseError> {
2496        let mut inner = Self::convert_into_iterator(pair);
2497        let pattern = inner.next().expect("should have inner");
2498
2499        match pattern.as_rule() {
2500            Rule::pattern => {
2501                let mut pattern_inner = Self::convert_into_iterator(&pattern);
2502                let pattern_type = pattern_inner.next().expect("should have inner");
2503
2504                match pattern_type.as_rule() {
2505                    Rule::enum_pattern => {
2506                        let mut inner = Self::convert_into_iterator(&pattern_type);
2507                        let variant = self.expect_local_type_identifier_next(&mut inner)?;
2508                        let elements = inner
2509                            .next()
2510                            .map(|p| self.parse_pattern_list(&p))
2511                            .transpose()?;
2512                        Ok((
2513                            NormalPattern::EnumPattern(variant.0, elements),
2514                            self.to_node(&pattern),
2515                        ))
2516                    }
2517                    Rule::pattern_list => {
2518                        let elements = self.parse_pattern_list(&pattern_type)?;
2519                        Ok((NormalPattern::PatternList(elements), self.to_node(&pattern)))
2520                    }
2521                    Rule::basic_literal => {
2522                        let (literal, node) = self.parse_basic_literal(&pattern_type)?;
2523                        Ok((NormalPattern::Literal(literal), node))
2524                    }
2525                    _ => {
2526                        Err(self.create_error_pair(SpecificError::UnknownMatchType, &pattern_type))
2527                    }
2528                }
2529            }
2530            _ => Err(self.create_error_pair(SpecificError::UnknownMatchType, &pattern)),
2531        }
2532    }
2533
2534    fn parse_pattern_list(&self, pair: &Pair<Rule>) -> Result<Vec<PatternElement>, ParseError> {
2535        let mut elements = Vec::new();
2536        for item in Self::convert_into_iterator(pair) {
2537            match item.as_rule() {
2538                Rule::pattern_field => {
2539                    let inner_pair = item.clone().into_inner().next().unwrap();
2540                    let maybe_mut_identifier = self.parse_maybe_mut_identifier(&inner_pair)?;
2541                    if inner_pair.as_str() == "_" {
2542                        elements.push(PatternElement::Wildcard(self.to_node(&item)));
2543                    } else {
2544                        elements.push(PatternElement::Variable(maybe_mut_identifier));
2545                    }
2546                }
2547                Rule::expression => {
2548                    elements.push(PatternElement::Expression(self.parse_expression(&item)?));
2549                }
2550                _ => {
2551                    return Err(self.create_error_pair(
2552                        SpecificError::UnexpectedPatternListElement(Self::pair_to_rule(&item)),
2553                        &item,
2554                    ));
2555                }
2556            }
2557        }
2558        Ok(elements)
2559    }
2560
2561    fn to_node(&self, pair: &Pair<Rule>) -> Node {
2562        let pair_span = pair.as_span();
2563        let span = SpanWithoutFileId {
2564            offset: pair_span.start() as u32,
2565            length: (pair_span.end() - pair_span.start()) as u16,
2566        };
2567
2568        Node { span }
2569    }
2570
2571    fn node_ex(pair: &Pair<Rule>) -> Node {
2572        let pair_span = pair.as_span();
2573        let span = SpanWithoutFileId {
2574            offset: pair_span.start() as u32,
2575            length: (pair_span.end() - pair_span.start()) as u16,
2576        };
2577
2578        Node { span }
2579    }
2580
2581    fn to_span(&self, pest_span: pest::Span) -> SpanWithoutFileId {
2582        SpanWithoutFileId {
2583            offset: pest_span.start() as u32,
2584            length: (pest_span.end() - pest_span.start()) as u16,
2585        }
2586    }
2587
2588    fn span(pest_span: pest::Span) -> SpanWithoutFileId {
2589        SpanWithoutFileId {
2590            offset: pest_span.start() as u32,
2591            length: (pest_span.end() - pest_span.start()) as u16,
2592        }
2593    }
2594
2595    fn create_expr(&self, kind: ExpressionKind, pair: &Pair<Rule>) -> Expression {
2596        self.create_expr_span(kind, self.to_node(pair))
2597    }
2598
2599    fn create_expr_span(&self, kind: ExpressionKind, node: Node) -> Expression {
2600        //info!(?kind, ?node, "create_expr()");
2601        Expression { kind, node }
2602    }
2603
2604    fn parse_multiplication(&self, pair: &Pair<Rule>) -> Result<Expression, ParseError> {
2605        let mut inner = pair.clone().into_inner();
2606        let mut expr = self.parse_prefix(&inner.next().unwrap())?;
2607        while let Some(op) = inner.next() {
2608            // Expect the next token to be a multiplication operator, then the next operand.
2609            let operator = self.parse_binary_operator(&op)?; // op_mul, op_div, or op_mod
2610            let right = self.parse_prefix(&inner.next().unwrap())?;
2611            expr = self.create_expr(
2612                ExpressionKind::BinaryOp(Box::new(expr), operator, Box::new(right)),
2613                pair,
2614            );
2615        }
2616        Ok(expr)
2617    }
2618
2619    fn parse_addition(&self, pair: &Pair<Rule>) -> Result<Expression, ParseError> {
2620        let mut inner = pair.clone().into_inner();
2621        let mut expr = self.parse_multiplication(&inner.next().unwrap())?;
2622        while let Some(op) = inner.next() {
2623            let operator = self.parse_binary_operator(&op)?; // op_add or op_sub
2624            let right = self.parse_multiplication(&inner.next().unwrap())?;
2625            expr = self.create_expr(
2626                ExpressionKind::BinaryOp(Box::new(expr), operator, Box::new(right)),
2627                pair,
2628            );
2629        }
2630        Ok(expr)
2631    }
2632
2633    fn parse_comparison(&self, pair: &Pair<Rule>) -> Result<Expression, ParseError> {
2634        let mut inner = pair.clone().into_inner();
2635        let mut expr = self.parse_addition(&inner.next().unwrap())?;
2636        while let Some(op) = inner.next() {
2637            let operator = self.parse_binary_operator(&op)?; // e.g. op_lt, op_eq, etc.
2638            let right = self.parse_addition(&inner.next().unwrap())?;
2639            expr = self.create_expr(
2640                ExpressionKind::BinaryOp(Box::new(expr), operator, Box::new(right)),
2641                pair,
2642            );
2643        }
2644        Ok(expr)
2645    }
2646
2647    fn parse_range(&self, pair: &Pair<Rule>) -> Result<Expression, ParseError> {
2648        let mut inner = pair.clone().into_inner();
2649        let left = self.parse_comparison(&inner.next().unwrap())?;
2650        if let Some(op) = inner.next() {
2651            let right = self.parse_comparison(&inner.next().unwrap())?;
2652            match op.as_rule() {
2653                Rule::exclusive_range_op => {
2654                    return Ok(self.create_expr(
2655                        ExpressionKind::Range(
2656                            Box::new(left),
2657                            Box::new(right),
2658                            RangeMode::Exclusive,
2659                        ),
2660                        pair,
2661                    ));
2662                }
2663                Rule::inclusive_range_op => {
2664                    return Ok(self.create_expr(
2665                        ExpressionKind::Range(
2666                            Box::new(left),
2667                            Box::new(right),
2668                            RangeMode::Inclusive,
2669                        ),
2670                        pair,
2671                    ));
2672                }
2673                _ => {}
2674            }
2675            let operator = self.parse_binary_operator(&op)?; // inclusive_range_op or exclusive_range_op
2676            Ok(self.create_expr(
2677                ExpressionKind::BinaryOp(Box::new(left), operator, Box::new(right)),
2678                pair,
2679            ))
2680        } else {
2681            Ok(left)
2682        }
2683    }
2684
2685    fn parse_logical(&self, pair: &Pair<Rule>) -> Result<Expression, ParseError> {
2686        let mut inner = pair.clone().into_inner();
2687        let mut expr = self.parse_range(&inner.next().unwrap())?;
2688        while let Some(op) = inner.next() {
2689            let operator = self.parse_binary_operator(&op)?; // op_and or op_or
2690            let right = self.parse_range(&inner.next().unwrap())?;
2691            expr = self.create_expr(
2692                ExpressionKind::BinaryOp(Box::new(expr), operator, Box::new(right)),
2693                pair,
2694            );
2695        }
2696        Ok(expr)
2697    }
2698}