harn_parser/
lib.rs

1pub mod analysis;
2mod ast;
3pub mod ast_json;
4pub mod builtin_signatures;
5pub mod const_eval;
6pub mod diagnostic;
7pub mod diagnostic_codes;
8pub mod harness_methods;
9mod parser;
10pub mod stdlib_metadata;
11pub mod typechecker;
12pub mod visit;
13
14pub use ast::*;
15pub use diagnostic_codes::{
16    Category as DiagnosticCodeCategory, Code as DiagnosticCode, ParseRepairSafetyError, Repair,
17    RepairId, RepairSafety, RepairTemplate, REPAIR_REGISTRY,
18};
19pub use parser::*;
20pub use stdlib_metadata::{parse_for_span as parse_stdlib_metadata, StdlibMetadata};
21pub use typechecker::{
22    block_definitely_exits, format_type, stmt_definitely_exits, DiagnosticDetails,
23    DiagnosticSeverity, InlayHintInfo, TypeChecker, TypeDiagnostic,
24};
25
26pub use builtin_signatures::install_builtin_signatures;
27
28/// Returns `true` if `name` is a builtin recognized by the parser's static analyzer.
29pub fn is_known_builtin(name: &str) -> bool {
30    builtin_signatures::is_builtin(name)
31}
32
33/// Every builtin name known to the parser, alphabetically. Enables bidirectional
34/// drift checks against the VM's runtime registry.
35pub fn known_builtin_names() -> impl Iterator<Item = &'static str> {
36    builtin_signatures::iter_builtin_names()
37}
38
39pub fn known_builtin_metadata() -> impl Iterator<Item = builtin_signatures::BuiltinMetadata> {
40    builtin_signatures::iter_builtin_metadata()
41}
42
43/// Error from a source processing pipeline stage. Wraps the inner error
44/// types so callers can dispatch on the failing stage.
45#[derive(Debug)]
46pub enum PipelineError {
47    Lex(harn_lexer::LexerError),
48    Parse(ParserError),
49    /// Boxed to keep the enum small on the stack — TypeDiagnostic contains
50    /// a Vec<FixEdit>.
51    TypeCheck(Box<TypeDiagnostic>),
52}
53
54impl std::fmt::Display for PipelineError {
55    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
56        match self {
57            PipelineError::Lex(e) => e.fmt(f),
58            PipelineError::Parse(e) => e.fmt(f),
59            PipelineError::TypeCheck(diag) => write!(f, "type error: {}", diag.message),
60        }
61    }
62}
63
64impl std::error::Error for PipelineError {}
65
66impl From<harn_lexer::LexerError> for PipelineError {
67    fn from(e: harn_lexer::LexerError) -> Self {
68        PipelineError::Lex(e)
69    }
70}
71
72impl From<ParserError> for PipelineError {
73    fn from(e: ParserError) -> Self {
74        PipelineError::Parse(e)
75    }
76}
77
78impl PipelineError {
79    /// Extract the source span, if any, for diagnostic rendering.
80    pub fn span(&self) -> Option<&harn_lexer::Span> {
81        match self {
82            PipelineError::Lex(e) => match e {
83                harn_lexer::LexerError::UnexpectedCharacter(_, span)
84                | harn_lexer::LexerError::UnterminatedString(span)
85                | harn_lexer::LexerError::UnterminatedBlockComment(span) => Some(span),
86            },
87            PipelineError::Parse(e) => match e {
88                ParserError::Unexpected { span, .. } => Some(span),
89                ParserError::UnexpectedEof { span, .. } => Some(span),
90            },
91            PipelineError::TypeCheck(diag) => diag.span.as_ref(),
92        }
93    }
94}
95
96/// Lex and parse source into an AST.
97pub fn parse_source(source: &str) -> Result<Vec<SNode>, PipelineError> {
98    let mut lexer = harn_lexer::Lexer::new(source);
99    let tokens = lexer.tokenize()?;
100    let mut parser = Parser::new(tokens);
101    Ok(parser.parse()?)
102}
103
104/// Lex, parse, and type-check source. Returns the AST and any type
105/// diagnostics (which may include warnings even on success).
106pub fn check_source(source: &str) -> Result<(Vec<SNode>, Vec<TypeDiagnostic>), PipelineError> {
107    let program = parse_source(source)?;
108    let diagnostics = TypeChecker::new().check_with_source(&program, source);
109    Ok((program, diagnostics))
110}
111
112/// Lex, parse, and type-check, bailing on the first type error.
113pub fn check_source_strict(source: &str) -> Result<Vec<SNode>, PipelineError> {
114    let (program, diagnostics) = check_source(source)?;
115    for diag in &diagnostics {
116        if diag.severity == DiagnosticSeverity::Error {
117            return Err(PipelineError::TypeCheck(Box::new(diag.clone())));
118        }
119    }
120    Ok(program)
121}
122
123#[cfg(test)]
124mod pipeline_tests {
125    use super::*;
126
127    #[test]
128    fn parse_source_valid() {
129        let program = parse_source("let x = 1").unwrap();
130        assert!(!program.is_empty());
131    }
132
133    #[test]
134    fn parse_source_lex_error() {
135        let err = parse_source("let x = `").unwrap_err();
136        assert!(matches!(err, PipelineError::Lex(_)));
137        assert!(err.span().is_some());
138        assert!(err.to_string().contains("Unexpected character"));
139    }
140
141    #[test]
142    fn parse_source_parse_error() {
143        let err = parse_source("let = 1").unwrap_err();
144        assert!(matches!(err, PipelineError::Parse(_)));
145        assert!(err.span().is_some());
146    }
147
148    #[test]
149    fn check_source_returns_diagnostics() {
150        let (program, _diagnostics) = check_source("let x = 1").unwrap();
151        assert!(!program.is_empty());
152    }
153
154    #[test]
155    fn check_source_strict_passes_valid_code() {
156        let program = check_source_strict("let x = 1\nlog(x)").unwrap();
157        assert!(!program.is_empty());
158    }
159
160    #[test]
161    fn check_source_strict_catches_lex_error() {
162        let err = check_source_strict("`").unwrap_err();
163        assert!(matches!(err, PipelineError::Lex(_)));
164    }
165
166    #[test]
167    fn pipeline_error_display_is_informative() {
168        let err = parse_source("`").unwrap_err();
169        let msg = err.to_string();
170        assert!(!msg.is_empty());
171        assert!(msg.contains('`') || msg.contains("Unexpected"));
172    }
173
174    #[test]
175    fn pipeline_error_size_is_bounded() {
176        // TypeCheck is boxed; guard against accidental growth of the other variants.
177        assert!(
178            std::mem::size_of::<PipelineError>() <= 96,
179            "PipelineError grew to {} bytes — consider boxing large variants",
180            std::mem::size_of::<PipelineError>()
181        );
182    }
183}
harn_parser/lib.rs

harn_parser/
lib.rs
