diff options
Diffstat (limited to 'dhall/src')
| -rw-r--r-- | dhall/src/main.rs | 2 | ||||
| -rw-r--r-- | dhall/src/parser.rs | 163 |
2 files changed, 83 insertions, 82 deletions
diff --git a/dhall/src/main.rs b/dhall/src/main.rs index cdab3c0..58826bb 100644 --- a/dhall/src/main.rs +++ b/dhall/src/main.rs @@ -52,7 +52,7 @@ fn print_error(message: &str, source: &str, start: usize, end: usize) { fn main() { let mut buffer = String::new(); io::stdin().read_to_string(&mut buffer).unwrap(); - let expr = match parser::parse_expr(&buffer) { + let expr = match parser::parse_expr_lalrpop(&buffer) { Ok(e) => e, Err(lalrpop_util::ParseError::User { error: lexer::LexicalError::Error(pos, e) }) => { print_error(&format!("Unexpected token {:?}", e), &buffer, pos, pos); diff --git a/dhall/src/parser.rs b/dhall/src/parser.rs index 0acfe39..9259dfd 100644 --- a/dhall/src/parser.rs +++ b/dhall/src/parser.rs @@ -7,7 +7,7 @@ use crate::core::{bx, Expr, V}; pub type ParseError<'i> = lalrpop_util::ParseError<usize, Tok<'i>, LexicalError>; -pub fn parse_expr(s: &str) -> Result<BoxExpr, ParseError> { +pub fn parse_expr_lalrpop(s: &str) -> Result<BoxExpr, ParseError> { grammar::ExprParser::new().parse(Lexer::new(s)) } @@ -48,80 +48,81 @@ fn debug_pair(pair: Pair<Rule>) { aux(0, "".into(), pair) } -pub fn parse_expr_pest(s: &str) -> Result<BoxExpr, Error<Rule>> { - let parsed_expr = DhallParser::parse(Rule::final_expression, s)?.next().unwrap(); - debug_pair(parsed_expr.clone()); - // println!("{}", parsed_expr.clone()); - - fn parse_binop<'a, F>(pair: Pair<'a, Rule>, mut f: F) -> BoxExpr<'a> - where F: FnMut(BoxExpr<'a>, BoxExpr<'a>) -> ParsedExpr<'a> { - let mut inner = pair.into_inner().map(parse_expression); - let first_expr = inner.next().unwrap(); - inner.fold(first_expr, |acc, e| bx(f(acc, e))) - } +fn parse_binop<'a, F>(pair: Pair<'a, Rule>, mut f: F) -> BoxExpr<'a> +where F: FnMut(BoxExpr<'a>, BoxExpr<'a>) -> ParsedExpr<'a> { + let mut inner = pair.into_inner().map(parse_expression); + let first_expr = inner.next().unwrap(); + inner.fold(first_expr, |acc, e| bx(f(acc, e))) +} - fn skip_expr(pair: Pair<Rule>) -> BoxExpr { - let mut inner = pair.into_inner().map(parse_expression); - inner.next().unwrap() - } +fn skip_expr(pair: Pair<Rule>) -> BoxExpr { + let mut inner = pair.into_inner().map(parse_expression); + inner.next().unwrap() +} - fn parse_str(pair: Pair<Rule>) -> &str { - pair.as_str().trim() - } +fn parse_str(pair: Pair<Rule>) -> &str { + pair.as_str().trim() +} - fn parse_natural(pair: Pair<Rule>) -> Result<usize, std::num::ParseIntError> { - parse_str(pair).parse() - } +fn parse_natural(pair: Pair<Rule>) -> Result<usize, std::num::ParseIntError> { + parse_str(pair).parse() +} - fn parse_expression(pair: Pair<Rule>) -> BoxExpr { - match pair.as_rule() { - Rule::natural_literal_raw => bx(Expr::NaturalLit(parse_natural(pair).unwrap())), - - Rule::annotated_expression => { parse_binop(pair, Expr::Annot) } - Rule::import_alt_expression => { skip_expr(pair) } - Rule::or_expression => { parse_binop(pair, Expr::BoolOr) } - Rule::plus_expression => { parse_binop(pair, Expr::NaturalPlus) } - Rule::text_append_expression => { parse_binop(pair, Expr::TextAppend) } - Rule::list_append_expression => { skip_expr(pair) } - Rule::and_expression => { parse_binop(pair, Expr::BoolAnd) } - Rule::combine_expression => { skip_expr(pair) } - Rule::prefer_expression => { skip_expr(pair) } - Rule::combine_types_expression => { skip_expr(pair) } - Rule::times_expression => { parse_binop(pair, Expr::NaturalTimes) } - Rule::equal_expression => { parse_binop(pair, Expr::BoolEQ) } - Rule::not_equal_expression => { parse_binop(pair, Expr::BoolNE) } - Rule::application_expression => { parse_binop(pair, Expr::App) } - - Rule::selector_expression_raw => { - let mut inner = pair.into_inner(); - let first_expr = parse_expression(inner.next().unwrap()); - inner.fold(first_expr, |acc, e| bx(Expr::Field(acc, e.as_str()))) - } +fn parse_expression(pair: Pair<Rule>) -> BoxExpr { + match pair.as_rule() { + Rule::natural_literal_raw => bx(Expr::NaturalLit(parse_natural(pair).unwrap())), + + Rule::annotated_expression => { parse_binop(pair, Expr::Annot) } + Rule::import_alt_expression => { skip_expr(pair) } + Rule::or_expression => { parse_binop(pair, Expr::BoolOr) } + Rule::plus_expression => { parse_binop(pair, Expr::NaturalPlus) } + Rule::text_append_expression => { parse_binop(pair, Expr::TextAppend) } + Rule::list_append_expression => { skip_expr(pair) } + Rule::and_expression => { parse_binop(pair, Expr::BoolAnd) } + Rule::combine_expression => { skip_expr(pair) } + Rule::prefer_expression => { skip_expr(pair) } + Rule::combine_types_expression => { skip_expr(pair) } + Rule::times_expression => { parse_binop(pair, Expr::NaturalTimes) } + Rule::equal_expression => { parse_binop(pair, Expr::BoolEQ) } + Rule::not_equal_expression => { parse_binop(pair, Expr::BoolNE) } + Rule::application_expression => { parse_binop(pair, Expr::App) } + + Rule::selector_expression_raw => { + let mut inner = pair.into_inner(); + let first_expr = parse_expression(inner.next().unwrap()); + inner.fold(first_expr, |acc, e| bx(Expr::Field(acc, e.as_str()))) + } - Rule::identifier_raw => { - let mut inner = pair.into_inner(); - let name = parse_str(inner.next().unwrap()); - let idx = inner.next().map(parse_natural).unwrap_or(Ok(0)).unwrap(); - bx(Expr::Var(V(name, idx))) - } + Rule::identifier_raw => { + let mut inner = pair.into_inner(); + let name = parse_str(inner.next().unwrap()); + let idx = inner.next().map(parse_natural).unwrap_or(Ok(0)).unwrap(); + bx(Expr::Var(V(name, idx))) + } - // Rule::record_type_or_literal => { - // let mut inner = pair.into_inner(); - // let first_expr = parse_expression(inner.next().unwrap()); - // inner.fold(first_expr, |acc, e| bx(Expr::Field(acc, e.as_str()))) - // } + // Rule::record_type_or_literal => { + // let mut inner = pair.into_inner(); + // let first_expr = parse_expression(inner.next().unwrap()); + // inner.fold(first_expr, |acc, e| bx(Expr::Field(acc, e.as_str()))) + // } - // r => panic!("{:?}", r), - // _ => bx(Expr::BoolLit(false)), + // r => panic!("{:?}", r), + // _ => bx(Expr::BoolLit(false)), - _ => { - let rulename = format!("{:?}", pair.as_rule()); - let mut inner = pair.into_inner().map(parse_expression).map(|x| *x); - bx(Expr::FailedParse(rulename, inner.collect())) - } + _ => { + let rulename = format!("{:?}", pair.as_rule()); + let mut inner = pair.into_inner().map(parse_expression).map(|x| *x); + bx(Expr::FailedParse(rulename, inner.collect())) } } +} + +pub fn parse_expr_pest(s: &str) -> Result<BoxExpr, Error<Rule>> { + let parsed_expr = DhallParser::parse(Rule::final_expression, s)?.next().unwrap(); + debug_pair(parsed_expr.clone()); + // println!("{}", parsed_expr.clone()); + Ok(parse_expression(parsed_expr)) } @@ -133,7 +134,7 @@ fn test_parse() { // let expr = r#"{ x = "foo", y = 4 }.x"#; // let expr = r#"(1 + 2) * 3"#; let expr = r#"if True then 1 + 3 * 5 else 2"#; - println!("{:?}", parse_expr(expr)); + println!("{:?}", parse_expr_lalrpop(expr)); match parse_expr_pest(expr) { Err(e) => { println!("{:?}", e); @@ -144,27 +145,27 @@ fn test_parse() { // assert_eq!(parse_expr_pest(expr).unwrap(), parse_expr(expr).unwrap()); assert!(false); - println!("test {:?}", parse_expr("3 + 5 * 10")); - assert!(parse_expr("22").is_ok()); - assert!(parse_expr("(22)").is_ok()); - assert_eq!(parse_expr("3 + 5 * 10").ok(), + println!("test {:?}", parse_expr_lalrpop("3 + 5 * 10")); + assert!(parse_expr_lalrpop("22").is_ok()); + assert!(parse_expr_lalrpop("(22)").is_ok()); + assert_eq!(parse_expr_lalrpop("3 + 5 * 10").ok(), Some(Box::new(NaturalPlus(Box::new(NaturalLit(3)), Box::new(NaturalTimes(Box::new(NaturalLit(5)), Box::new(NaturalLit(10)))))))); // The original parser is apparently right-associative - assert_eq!(parse_expr("2 * 3 * 4").ok(), + assert_eq!(parse_expr_lalrpop("2 * 3 * 4").ok(), Some(Box::new(NaturalTimes(Box::new(NaturalLit(2)), Box::new(NaturalTimes(Box::new(NaturalLit(3)), Box::new(NaturalLit(4)))))))); - assert!(parse_expr("((((22))))").is_ok()); - assert!(parse_expr("((22)").is_err()); - println!("{:?}", parse_expr("\\(b : Bool) -> b == False")); - assert!(parse_expr("\\(b : Bool) -> b == False").is_ok()); - println!("{:?}", parse_expr("foo.bar")); - assert!(parse_expr("foo.bar").is_ok()); - assert!(parse_expr("[] : List Bool").is_ok()); - - // println!("{:?}", parse_expr("< Left = True | Right : Natural >")); - // println!("{:?}", parse_expr(r#""bl${42}ah""#)); - // assert!(parse_expr("< Left = True | Right : Natural >").is_ok()); + assert!(parse_expr_lalrpop("((((22))))").is_ok()); + assert!(parse_expr_lalrpop("((22)").is_err()); + println!("{:?}", parse_expr_lalrpop("\\(b : Bool) -> b == False")); + assert!(parse_expr_lalrpop("\\(b : Bool) -> b == False").is_ok()); + println!("{:?}", parse_expr_lalrpop("foo.bar")); + assert!(parse_expr_lalrpop("foo.bar").is_ok()); + assert!(parse_expr_lalrpop("[] : List Bool").is_ok()); + + // println!("{:?}", parse_expr_lalrpop("< Left = True | Right : Natural >")); + // println!("{:?}", parse_expr_lalrpop(r#""bl${42}ah""#)); + // assert!(parse_expr_lalrpop("< Left = True | Right : Natural >").is_ok()); } |