hawdb_sql/
ast.rs

1// Copyright 2026 Nowledge
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15pub use hawdb_expression::sql::{
16    Expr, ExprKind, SqlColumnRef, SqlComparisonOp, SqlExpression, SqlFunctionArgument,
17    SqlIndexColumn, SqlLikeEscape, SqlNullOrder, SqlOrderDirection, SqlOrderItem, SqlPredicate,
18    SqlSourceLocation, SqlSourceSpan, SqlValue,
19};
20
21use caseless::Caseless;
22use hawdb_core::{HawDBError, LogicalType, Result};
23
24#[derive(Debug, Clone, PartialEq, Eq)]
25pub enum SqlStatement {
26    Explain(SqlExplainStatement),
27    Select(SelectStatement),
28    Insert(InsertStatement),
29    Update(UpdateStatement),
30    Delete(DeleteStatement),
31    CreateTable(CreateTableStatement),
32    CreateIndex(CreateIndexStatement),
33    CreateMaterializedView(CreateMaterializedViewStatement),
34    DropMaterializedView(DropMaterializedViewStatement),
35    AlterTableAddColumn(AlterTableAddColumnStatement),
36    /// Project-scoped branch lifecycle commands. These are deliberately
37    /// distinct from relational DDL: their executor operates on the durable
38    /// branch catalog rather than a selected branch's schema.
39    Branch(BranchSqlStatement),
40}
41
42#[derive(Debug, Clone, PartialEq, Eq)]
43pub struct CreateMaterializedViewStatement {
44    pub name: SqlTableName,
45    pub if_not_exists: bool,
46    pub query: Box<SelectStatement>,
47}
48
49#[derive(Debug, Clone, PartialEq, Eq)]
50pub struct DropMaterializedViewStatement {
51    pub name: SqlTableName,
52    pub if_exists: bool,
53}
54
55/// A branch lifecycle command parsed by the PostgreSQL entrypoint.
56///
57/// Keeping this as an AST family makes branch operations visible to the query
58/// runtime and prevents a host integration from recognizing command strings
59/// itself. Lifecycle and selection commands dispatch outside ordinary implicit
60/// data transactions through the storage-owned admission/publication kernel.
61#[derive(Debug, Clone, PartialEq, Eq)]
62pub enum BranchSqlStatement {
63    ShowBranches(ShowBranchesStatement),
64    ShowBranch(ShowBranchStatement),
65    ShowCurrentBranch,
66    UseBranch(BranchSqlSelector),
67    CreateBranch(CreateBranchStatement),
68    DropBranch(DropBranchStatement),
69}
70
71impl BranchSqlStatement {
72    pub const fn changes_context_or_catalog(&self) -> bool {
73        matches!(
74            self,
75            Self::UseBranch(_) | Self::CreateBranch(_) | Self::DropBranch(_)
76        )
77    }
78
79    pub const fn command(&self) -> &'static str {
80        match self {
81            Self::ShowBranches(_) => "SHOW BRANCHES",
82            Self::ShowBranch(_) => "SHOW BRANCH",
83            Self::ShowCurrentBranch => "SHOW CURRENT BRANCH",
84            Self::UseBranch(_) => "USE BRANCH",
85            Self::CreateBranch(_) => "CREATE BRANCH",
86            Self::DropBranch(_) => "DROP BRANCH",
87        }
88    }
89}
90
91#[derive(Debug, Clone, PartialEq, Eq)]
92pub struct CreateBranchStatement {
93    pub name: Option<BranchSqlValue>,
94    pub source: BranchSqlSelector,
95    pub expected_source_revision: SqlBound,
96    pub request_key: BranchSqlValue,
97    pub owner: Option<BranchSqlValue>,
98}
99
100#[derive(Debug, Clone, PartialEq, Eq)]
101pub struct DropBranchStatement {
102    pub id: BranchSqlValue,
103    pub expected_metadata_revision: SqlBound,
104}
105
106/// A bounded page over the durable branch catalog.
107#[derive(Debug, Clone, PartialEq, Eq)]
108pub struct ShowBranchesStatement {
109    pub limit: SqlBound,
110    pub offset: Option<SqlBound>,
111}
112
113#[derive(Debug, Clone, PartialEq, Eq)]
114pub struct ShowBranchStatement {
115    pub selector: BranchSqlSelector,
116}
117
118/// A typed selector avoids treating UUID-looking names as identifiers. The
119/// runtime validates `Id` values as UUIDs only after parameter binding.
120#[derive(Debug, Clone, PartialEq, Eq)]
121pub enum BranchSqlSelector {
122    Name(BranchSqlValue),
123    Id(BranchSqlValue),
124}
125
126/// A branch name, UUID, or opaque selector parameter. Branch commands accept
127/// only string literals or PostgreSQL positional parameters, never SQL
128/// expression evaluation or interpolated text.
129#[derive(Debug, Clone, PartialEq, Eq)]
130pub enum BranchSqlValue {
131    Literal(String),
132    Parameter(usize),
133}
134
135#[derive(Debug, Clone, PartialEq, Eq)]
136pub struct SqlExplainStatement {
137    pub analyze: bool,
138    pub statement: Box<SqlStatement>,
139}
140
141#[derive(Debug, Clone, PartialEq, Eq)]
142pub struct SqlVectorIndexSearch {
143    pub index: SqlValue,
144    pub embedding: SqlValue,
145    pub mode: hawdb_core::VectorIndexQueryMode,
146    pub candidates: Option<SqlValue>,
147    pub max_work: Option<SqlValue>,
148    pub top_k: SqlValue,
149}
150
151#[derive(Debug, Clone, PartialEq, Eq)]
152pub struct SelectStatement {
153    pub vector_index: Option<Box<SqlVectorIndexSearch>>,
154    pub projection: Vec<SelectProjection>,
155    pub distinct: bool,
156    /// `None` for a FROM-less SELECT (e.g. `SELECT version();`): the
157    /// projection is evaluated exactly once against an implicit row with no
158    /// column bindings, so any column reference in it is rejected the same
159    /// way an unresolvable column against a real table would be.
160    pub from: Option<SqlTableName>,
161    pub from_alias: Option<String>,
162    pub joins: Vec<SqlJoin>,
163    pub selection: Option<SqlPredicate>,
164    pub group_by: Vec<SqlColumnRef>,
165    pub having: Option<SqlPredicate>,
166    pub order_by: Vec<SqlOrderItem>,
167    pub limit: Option<SqlBound>,
168    pub offset: Option<SqlBound>,
169    pub lock_strength: Option<SqlLockStrength>,
170}
171
172impl SelectStatement {
173    /// The base table, for every code path that only ever runs on a real
174    /// table (catalog resolution, access-path selection, join planning, row
175    /// scanning). FROM-less selects never reach these paths — they're
176    /// handled by a separate, earlier branch — so `None` here is a caller
177    /// bug, not a user-facing state.
178    pub fn from_table(&self) -> &SqlTableName {
179        self.from
180            .as_ref()
181            .expect("from_table called on a FROM-less SELECT; it must take the fromless path")
182    }
183}
184
185#[derive(Debug, Clone, Copy, PartialEq, Eq)]
186pub enum SqlLockStrength {
187    Share,
188    Update,
189}
190
191#[derive(Debug, Clone, PartialEq, Eq)]
192pub struct InsertStatement {
193    pub table: SqlTableName,
194    pub columns: Vec<String>,
195    pub rows: Vec<Vec<SqlValue>>,
196    pub on_conflict: Option<SqlOnConflict>,
197    pub returning: Vec<SqlColumnRef>,
198}
199
200#[derive(Debug, Clone, PartialEq, Eq)]
201pub struct UpdateStatement {
202    pub table: SqlTableName,
203    pub alias: Option<String>,
204    pub assignments: Vec<SqlAssignment>,
205    pub selection: Option<SqlPredicate>,
206}
207
208#[derive(Debug, Clone, PartialEq, Eq)]
209pub struct DeleteStatement {
210    pub table: SqlTableName,
211    pub alias: Option<String>,
212    pub selection: Option<SqlPredicate>,
213}
214
215#[derive(Debug, Clone, PartialEq, Eq)]
216pub struct SqlAssignment {
217    pub column: String,
218    pub value: SqlAssignmentValue,
219}
220
221#[derive(Debug, Clone, PartialEq, Eq)]
222pub enum SqlAssignmentValue {
223    Expression(Expr),
224    Value(SqlValue),
225    Column(SqlColumnRef),
226    Arithmetic {
227        left: SqlArithmeticOperand,
228        operator: SqlArithmeticOperator,
229        right: SqlArithmeticOperand,
230    },
231}
232
233#[derive(Debug, Clone, PartialEq, Eq)]
234pub enum SqlArithmeticOperand {
235    Value(SqlValue),
236    Column(SqlColumnRef),
237}
238
239#[derive(Debug, Clone, Copy, PartialEq, Eq)]
240pub enum SqlArithmeticOperator {
241    Add,
242    Subtract,
243}
244
245#[derive(Debug, Clone, PartialEq, Eq)]
246pub struct SqlOnConflict {
247    pub columns: Vec<String>,
248    pub action: SqlConflictAction,
249}
250
251#[derive(Debug, Clone, PartialEq, Eq)]
252pub enum SqlConflictAction {
253    DoNothing,
254    DoUpdate(Vec<SqlAssignment>),
255}
256
257#[derive(Debug, Clone, PartialEq, Eq)]
258pub struct CreateTableStatement {
259    pub table: SqlTableName,
260    pub if_not_exists: bool,
261    pub columns: Vec<SqlColumnDefinition>,
262    pub constraints: Vec<SqlTableConstraint>,
263    pub storage: SqlTableStorage,
264}
265
266#[derive(Debug, Clone, PartialEq, Eq, Default)]
267pub enum SqlTableStorage {
268    #[default]
269    RowPage,
270    StrictAppend {
271        partition_key: Vec<String>,
272        order_key: Vec<String>,
273        generated_order: SqlGeneratedOrder,
274    },
275}
276
277#[derive(Debug, Clone, Copy, Default, PartialEq, Eq)]
278pub enum SqlGeneratedOrder {
279    #[default]
280    CallerProvided,
281    CommitSequence,
282}
283
284#[derive(Debug, Clone, PartialEq, Eq)]
285pub struct SqlColumnDefinition {
286    pub name: String,
287    pub data_type: SqlDataType,
288    pub nullable: bool,
289    pub default: Option<SqlColumnDefault>,
290    pub primary_key: bool,
291    pub unique: bool,
292    pub references: Option<SqlForeignKeyReference>,
293}
294
295#[derive(Debug, Clone, PartialEq, Eq)]
296pub enum SqlColumnDefault {
297    Literal(SqlValue),
298    UuidV7,
299}
300
301#[derive(Debug, Clone, Copy, PartialEq, Eq)]
302pub enum SqlDataType {
303    Boolean,
304    BigInt,
305    DoublePrecision,
306    Decimal(hawdb_core::DecimalType),
307    Text,
308    Bytea,
309    Uuid,
310    Vector(hawdb_core::VectorDimension),
311}
312
313impl SqlDataType {
314    pub const fn logical_type(self) -> LogicalType {
315        match self {
316            Self::Boolean => LogicalType::Boolean,
317            Self::BigInt => LogicalType::Int64,
318            Self::DoublePrecision => LogicalType::Float64,
319            Self::Decimal(_) => LogicalType::Decimal,
320            Self::Text => LogicalType::Text,
321            Self::Bytea => LogicalType::Binary,
322            Self::Uuid => LogicalType::Uuid,
323            Self::Vector(dimension) => LogicalType::Vector(dimension),
324        }
325    }
326}
327
328#[derive(Debug, Clone, PartialEq, Eq)]
329pub enum SqlTableConstraint {
330    PrimaryKey(Vec<String>),
331    Unique(Vec<String>),
332    ForeignKey {
333        columns: Vec<String>,
334        reference: SqlForeignKeyReference,
335    },
336}
337
338#[derive(Debug, Clone, PartialEq, Eq)]
339pub struct SqlForeignKeyReference {
340    pub table: SqlTableName,
341    pub columns: Vec<String>,
342    pub on_delete: SqlReferentialAction,
343    pub on_update: SqlReferentialAction,
344}
345
346#[derive(Debug, Clone, Copy, PartialEq, Eq)]
347pub enum SqlReferentialAction {
348    NoAction,
349    Restrict,
350    Cascade,
351    SetNull,
352}
353
354#[derive(Debug, Clone, PartialEq, Eq)]
355pub struct CreateIndexStatement {
356    pub name: String,
357    pub table: SqlTableName,
358    pub columns: Vec<SqlIndexColumn>,
359    pub unique: bool,
360    pub if_not_exists: bool,
361}
362
363#[derive(Debug, Clone, PartialEq, Eq)]
364pub struct AlterTableAddColumnStatement {
365    pub table: SqlTableName,
366    pub if_not_exists: bool,
367    pub column: SqlColumnDefinition,
368}
369
370#[derive(Debug, Clone, Copy, PartialEq, Eq)]
371pub enum SqlBound {
372    Literal(u64),
373    Parameter(usize),
374}
375
376#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
377pub struct SqlTableName {
378    pub schema: Option<String>,
379    pub name: String,
380}
381
382#[derive(Debug, Clone, PartialEq, Eq)]
383pub enum SelectProjection {
384    Wildcard,
385    Expression {
386        expression: SqlExpression,
387        alias: Option<String>,
388    },
389}
390
391#[derive(Debug, Clone, PartialEq, Eq)]
392pub struct SqlJoin {
393    pub kind: SqlJoinKind,
394    pub table: SqlTableName,
395    pub alias: Option<String>,
396    pub on: SqlPredicate,
397    /// First input visible to ON, with the SELECT base relation at ordinal zero.
398    /// The current join's right input is the inclusive end of this scope.
399    pub on_scope_start: usize,
400}
401
402#[derive(Debug, Clone, Copy, PartialEq, Eq)]
403pub enum SqlJoinKind {
404    Inner,
405    Left,
406}
407
408/// Matches SQL LIKE patterns with locale-independent Unicode default case folding for ILIKE.
409pub fn sql_like_matches(
410    value: &str,
411    pattern: &str,
412    escape: SqlLikeEscape,
413    case_insensitive: bool,
414) -> Result<bool> {
415    let layout = like_layout(pattern, escape, case_insensitive)?;
416    let value_chars = value.chars().count();
417    layout.scratch_bytes(value_chars)?;
418    let (tokens, literals) = tokenize_like_pattern(pattern, escape, case_insensitive, &layout)?;
419    let mut characters = Vec::with_capacity(value_chars);
420    characters.extend(value.chars());
421    let value = characters;
422
423    let mut value_index = 0;
424    let mut pattern_index = 0;
425    let mut wildcard_index = None;
426    let mut wildcard_value_index = 0;
427    while value_index < value.len() {
428        let matched = match tokens.get(pattern_index) {
429            Some(LikeToken::Literal(expected)) => {
430                if let Some(consumed) = match_like_literal(
431                    &value[value_index..],
432                    &literals[expected.clone()],
433                    case_insensitive,
434                ) {
435                    value_index += consumed;
436                    pattern_index += 1;
437                    true
438                } else {
439                    false
440                }
441            }
442            Some(LikeToken::One) => {
443                value_index += 1;
444                pattern_index += 1;
445                true
446            }
447            Some(LikeToken::Many) => {
448                wildcard_index = Some(pattern_index);
449                wildcard_value_index = value_index;
450                pattern_index += 1;
451                true
452            }
453            None => false,
454        };
455        if matched {
456            continue;
457        }
458        let Some(wildcard_index) = wildcard_index else {
459            return Ok(false);
460        };
461        wildcard_value_index += 1;
462        value_index = wildcard_value_index;
463        pattern_index = wildcard_index + 1;
464    }
465    while matches!(tokens.get(pattern_index), Some(LikeToken::Many)) {
466        pattern_index += 1;
467    }
468    Ok(pattern_index == tokens.len())
469}
470
471/// Requested heap bytes used by the LIKE matcher, before allocating its buffers.
472/// Escape parsing and Unicode folding share the matcher's exact layout pass.
473#[doc(hidden)]
474pub fn sql_like_scratch_bytes(
475    value: &str,
476    pattern: &str,
477    escape: SqlLikeEscape,
478    case_insensitive: bool,
479) -> Result<usize> {
480    like_layout(pattern, escape, case_insensitive)?.scratch_bytes(value.chars().count())
481}
482
483struct LikeLayout {
484    tokens: usize,
485    literal_bytes: usize,
486}
487
488impl LikeLayout {
489    fn scratch_bytes(&self, value_chars: usize) -> Result<usize> {
490        self.tokens
491            .checked_mul(std::mem::size_of::<LikeToken>())
492            .and_then(|bytes| bytes.checked_add(self.literal_bytes))
493            .and_then(|bytes| {
494                value_chars
495                    .checked_mul(std::mem::size_of::<char>())
496                    .and_then(|value| bytes.checked_add(value))
497            })
498            .ok_or_else(like_size_overflow)
499    }
500}
501
502#[derive(Debug, Clone)]
503enum LikeToken {
504    Literal(std::ops::Range<usize>),
505    One,
506    Many,
507}
508
509#[derive(Clone, Copy)]
510enum LikePart {
511    Literal(char),
512    One,
513    Many,
514}
515
516fn like_size_overflow() -> HawDBError {
517    HawDBError::Execution("LIKE scratch length overflow".into())
518}
519
520fn visit_like_pattern(
521    pattern: &str,
522    escape: SqlLikeEscape,
523    mut visit: impl FnMut(LikePart) -> Result<()>,
524) -> Result<()> {
525    let escape = match escape {
526        SqlLikeEscape::Character(character) => Some(character),
527        SqlLikeEscape::Disabled => None,
528    };
529    let mut characters = pattern.chars();
530    while let Some(character) = characters.next() {
531        let part = if Some(character) == escape {
532            LikePart::Literal(characters.next().ok_or_else(|| {
533                HawDBError::Semantic("LIKE pattern ends with its escape character".to_string())
534            })?)
535        } else {
536            match character {
537                '%' => LikePart::Many,
538                '_' => LikePart::One,
539                literal => LikePart::Literal(literal),
540            }
541        };
542        visit(part)?;
543    }
544    Ok(())
545}
546
547fn visit_like_literal(
548    literal: char,
549    case_insensitive: bool,
550    mut visit: impl FnMut(char) -> Result<()>,
551) -> Result<()> {
552    if case_insensitive {
553        for character in std::iter::once(literal).default_case_fold() {
554            visit(character)?;
555        }
556        Ok(())
557    } else {
558        visit(literal)
559    }
560}
561
562fn like_layout(pattern: &str, escape: SqlLikeEscape, case_insensitive: bool) -> Result<LikeLayout> {
563    let mut layout = LikeLayout {
564        tokens: 0,
565        literal_bytes: 0,
566    };
567    let mut previous = None;
568    visit_like_pattern(pattern, escape, |part| {
569        let merged = matches!(
570            (previous, part),
571            (Some(LikePart::Many), LikePart::Many)
572                | (Some(LikePart::Literal(_)), LikePart::Literal(_))
573        );
574        if !merged {
575            layout.tokens = layout
576                .tokens
577                .checked_add(1)
578                .ok_or_else(like_size_overflow)?;
579        }
580        if let LikePart::Literal(literal) = part {
581            visit_like_literal(literal, case_insensitive, |character| {
582                layout.literal_bytes = layout
583                    .literal_bytes
584                    .checked_add(character.len_utf8())
585                    .ok_or_else(like_size_overflow)?;
586                Ok(())
587            })?;
588        }
589        previous = Some(part);
590        Ok(())
591    })?;
592    Ok(layout)
593}
594
595fn tokenize_like_pattern(
596    pattern: &str,
597    escape: SqlLikeEscape,
598    case_insensitive: bool,
599    layout: &LikeLayout,
600) -> Result<(Vec<LikeToken>, String)> {
601    let mut tokens = Vec::with_capacity(layout.tokens);
602    let mut literals = String::with_capacity(layout.literal_bytes);
603    visit_like_pattern(pattern, escape, |part| {
604        match part {
605            LikePart::Literal(literal) => {
606                let start = literals.len();
607                visit_like_literal(literal, case_insensitive, |character| {
608                    literals.push(character);
609                    Ok(())
610                })?;
611                if let Some(LikeToken::Literal(range)) = tokens.last_mut() {
612                    range.end = literals.len();
613                } else {
614                    tokens.push(LikeToken::Literal(start..literals.len()));
615                }
616            }
617            LikePart::Many if !matches!(tokens.last(), Some(LikeToken::Many)) => {
618                tokens.push(LikeToken::Many)
619            }
620            LikePart::Many => {}
621            LikePart::One => tokens.push(LikeToken::One),
622        }
623        Ok(())
624    })?;
625    debug_assert_eq!(tokens.len(), layout.tokens);
626    debug_assert_eq!(literals.len(), layout.literal_bytes);
627    Ok((tokens, literals))
628}
629
630fn match_like_literal(value: &[char], expected: &str, case_insensitive: bool) -> Option<usize> {
631    let mut expected = expected.chars().peekable();
632    for (index, character) in value.iter().copied().enumerate() {
633        if case_insensitive {
634            for folded in std::iter::once(character).default_case_fold() {
635                if expected.next() != Some(folded) {
636                    return None;
637                }
638            }
639        } else if expected.next() != Some(character) {
640            return None;
641        }
642        // Wildcards and literal boundaries consume complete source characters,
643        // even when one character folds into several code points.
644        if expected.peek().is_none() {
645            return Some(index + 1);
646        }
647    }
648    None
649}
650
651#[cfg(test)]
652mod tests {
653    use super::*;
654
655    #[test]
656    fn postgres_data_types_use_shared_logical_types() {
657        assert_eq!(SqlDataType::Boolean.logical_type(), LogicalType::Boolean);
658        assert_eq!(SqlDataType::BigInt.logical_type(), LogicalType::Int64);
659        assert_eq!(
660            SqlDataType::DoublePrecision.logical_type(),
661            LogicalType::Float64
662        );
663        assert_eq!(SqlDataType::Text.logical_type(), LogicalType::Text);
664        assert_eq!(SqlDataType::Bytea.logical_type(), LogicalType::Binary);
665    }
666}
hawdb_sql/ast.rs

hawdb_sql/
ast.rs
