diff options
| -rw-r--r-- | dhall_core/src/parser.rs | 236 |
1 files changed, 153 insertions, 83 deletions
diff --git a/dhall_core/src/parser.rs b/dhall_core/src/parser.rs index 45930d4..9a9560f 100644 --- a/dhall_core/src/parser.rs +++ b/dhall_core/src/parser.rs @@ -231,7 +231,8 @@ macro_rules! match_iter_branching { macro_rules! match_pair { (@type_callback, $ty:ident, $x:expr) => { - $ty($x) + ParseUnwrapped::$ty($x) + // ParseWrapped::$ty($x).map(|x| x.$ty()) }; (@branch_callback, children, $pair:expr; $($args:tt)*) => { { @@ -274,13 +275,75 @@ macro_rules! match_pair { }; } +macro_rules! make_parser { + ($( $submac:ident!( $name:ident<$o:ty>; $($args:tt)* ); )*) => ( + // #[allow(non_camel_case_types, dead_code)] + // enum ParsedType { + // $( $name, )* + // } + + // impl ParsedType { + // #[allow(dead_code)] + // fn parse(self, pair: Pair<Rule>) -> ParseResult<ParsedValue> { + // match self { + // $( ParsedType::$name => { + // let ret = $name(pair)?; + // Ok(ParsedValue::$name(ret)) + // }, )* + // } + // } + // // fn parse(self, pair: Pair<Rule>) -> ParseResult<ParsedValue> { + // // match self { + // // $( ParsedType::$name => $name(pair), )* + // // } + // // } + // } + struct ParseWrapped; + struct ParseUnwrapped; + + #[allow(non_camel_case_types, dead_code)] + enum ParsedValue<'a> { + $( $name($o), )* + } + + impl<'a> ParsedValue<'a> { + $( + #[allow(non_snake_case, dead_code)] + fn $name(self) -> $o { + match self { + ParsedValue::$name(x) => x, + _ => unreachable!(), + } + } + )* + } + + // fn do_the_parse(s: &str, r: Rule, ty: ParsedType) -> ParseResult<ParsedValue> { + // let pairs = DhallParser::parse(r, s)?; + // match_iter!(pairs; (e) => ty.parse(e)) + // } + + $( + $submac!($name<$o>; $($args)*); + )* + ); +} + + macro_rules! make_pest_parse_function { ($name:ident<$o:ty>; $submac:ident!( $($args:tt)* )) => ( - #[allow(unused_variables)] - #[allow(non_snake_case)] - #[allow(clippy::all)] - fn $name<'a>(pair: Pair<'a, Rule>) -> ParseResult<$o> { - $submac!(pair; $($args)*) + impl ParseUnwrapped { + #[allow(unused_variables, non_snake_case, dead_code, clippy::all)] + fn $name<'a>(pair: Pair<'a, Rule>) -> ParseResult<$o> { + ParseWrapped::$name(pair).map(|x| x.$name()) + } + } + impl ParseWrapped { + #[allow(unused_variables, non_snake_case, dead_code, clippy::all)] + fn $name<'a>(pair: Pair<'a, Rule>) -> ParseResult<ParsedValue<'a>> { + let res: ParseResult<$o> = $submac!(pair; $($args)*); + Ok(ParsedValue::$name(res?)) + } } ); } @@ -303,7 +366,7 @@ macro_rules! rule_group { ($name:ident<$o:ty>; $($ty:ident),*) => ( make_pest_parse_function!($name<$o>; match_rule!( $( - Rule::$ty => match_pair!(raw_pair!(p) => $ty(p)?), + Rule::$ty => match_pair!(raw_pair!(p) => ParseUnwrapped::$ty(p)?), )* )); ); @@ -323,6 +386,71 @@ macro_rules! match_rule { }; } +// List of rules that can be shortcutted as implemented in binop!() +fn can_be_shortcutted(rule: Rule) -> bool { + use Rule::*; + match rule { + import_alt_expression + | or_expression + | plus_expression + | text_append_expression + | list_append_expression + | and_expression + | combine_expression + | prefer_expression + | combine_types_expression + | times_expression + | equal_expression + | not_equal_expression + | application_expression + | selector_expression_raw + | annotated_expression => true, + _ => false, + } +} + +macro_rules! binop { + ($rule:ident<$ty:ty>; $op:ident) => { + rule!($rule<$ty>; + raw_pair!(pair) => { + // This all could be a trivial fold, but to avoid stack explosion + // we try to cut down on the recursion level here, by consuming + // chains of blah_expression > ... > blih_expression in one go. + let mut pair = pair; + let mut pairs = pair.into_inner(); + let first = pairs.next().unwrap(); + let rest: Vec<_> = pairs.map(ParseUnwrapped::expression).collect::<Result<_, _>>()?; + if !rest.is_empty() { + // If there is more than one subexpression, handle it normally + let first = ParseUnwrapped::expression(first)?; + rest.into_iter().fold(first, |acc, e| bx(Expr::BinOp(BinOp::$op, acc, e))) + } else { + // Otherwise, consume short-cuttable rules as long as they contain only one subexpression. + // println!("short-cutting {}", debug_pair(pair.clone())); + pair = first; + while can_be_shortcutted(pair.as_rule()) { + let mut pairs = pair.clone().into_inner(); + let first = pairs.next().unwrap(); + let rest: Vec<_> = pairs.collect(); + if !rest.is_empty() { + break; + } + pair = first; + } + // println!("short-cutted {}", debug_pair(pair.clone())); + // println!(); + ParseUnwrapped::expression(pair)? + } + } + // children!(first: expression, rest..: expression) => { + // rest.fold(first, |acc, e| bx(Expr::BinOp(BinOp::$op, acc, e))) + // } + ); + }; +} + + +make_parser!{ rule!(EOI<()>; children!() => ()); named!(str<&'a str>; captured_str!(s) => s.trim()); @@ -584,81 +712,18 @@ rule!(non_empty_optional<RcExpr>; } ); -// List of rules that can be shortcutted as implemented in binop!() -fn can_be_shortcutted(rule: Rule) -> bool { - use Rule::*; - match rule { - import_alt_expression - | or_expression - | plus_expression - | text_append_expression - | list_append_expression - | and_expression - | combine_expression - | prefer_expression - | combine_types_expression - | times_expression - | equal_expression - | not_equal_expression - | application_expression - | selector_expression_raw - | annotated_expression => true, - _ => false, - } -} - -macro_rules! binop { - ($rule:ident, $op:ident) => { - rule!($rule<RcExpr>; - raw_pair!(pair) => { - // This all could be a trivial fold, but to avoid stack explosion - // we try to cut down on the recursion level here, by consuming - // chains of blah_expression > ... > blih_expression in one go. - let mut pair = pair; - let mut pairs = pair.into_inner(); - let first = pairs.next().unwrap(); - let rest: Vec<_> = pairs.map(expression).collect::<Result<_, _>>()?; - if !rest.is_empty() { - // If there is more than one subexpression, handle it normally - let first = expression(first)?; - rest.into_iter().fold(first, |acc, e| bx(Expr::BinOp(BinOp::$op, acc, e))) - } else { - // Otherwise, consume short-cuttable rules as long as they contain only one subexpression. - // println!("short-cutting {}", debug_pair(pair.clone())); - pair = first; - while can_be_shortcutted(pair.as_rule()) { - let mut pairs = pair.clone().into_inner(); - let first = pairs.next().unwrap(); - let rest: Vec<_> = pairs.collect(); - if !rest.is_empty() { - break; - } - pair = first; - } - // println!("short-cutted {}", debug_pair(pair.clone())); - // println!(); - expression(pair)? - } - } - // children!(first: expression, rest..: expression) => { - // rest.fold(first, |acc, e| bx(Expr::BinOp(BinOp::$op, acc, e))) - // } - ); - }; -} - -binop!(import_alt_expression, ImportAlt); -binop!(or_expression, BoolOr); -binop!(plus_expression, NaturalPlus); -binop!(text_append_expression, TextAppend); -binop!(list_append_expression, ListAppend); -binop!(and_expression, BoolAnd); -binop!(combine_expression, Combine); -binop!(prefer_expression, Prefer); -binop!(combine_types_expression, CombineTypes); -binop!(times_expression, NaturalTimes); -binop!(equal_expression, BoolEQ); -binop!(not_equal_expression, BoolNE); +binop!(import_alt_expression<RcExpr>; ImportAlt); +binop!(or_expression<RcExpr>; BoolOr); +binop!(plus_expression<RcExpr>; NaturalPlus); +binop!(text_append_expression<RcExpr>; TextAppend); +binop!(list_append_expression<RcExpr>; ListAppend); +binop!(and_expression<RcExpr>; BoolAnd); +binop!(combine_expression<RcExpr>; Combine); +binop!(prefer_expression<RcExpr>; Prefer); +binop!(combine_types_expression<RcExpr>; CombineTypes); +binop!(times_expression<RcExpr>; NaturalTimes); +binop!(equal_expression<RcExpr>; BoolEQ); +binop!(not_equal_expression<RcExpr>; BoolNE); rule!(annotated_expression<RcExpr>; children!(e: expression, annot: expression) => { @@ -812,12 +877,17 @@ rule!(non_empty_list_literal_raw<RcExpr>; rule!(final_expression<RcExpr>; children!(e: expression, _eoi: EOI) => e ); +} pub fn parse_expr(s: &str) -> ParseResult<RcExpr> { let pairs = DhallParser::parse(Rule::final_expression, s)?; // Match the only item in the pairs iterator // println!("{}", debug_pair(pairs.clone().next().unwrap())); - iter_patterns::destructure_iter!(pairs; [p] => expression(p)).unwrap() + let expr = iter_patterns::destructure_iter!(pairs; [p] => ParseUnwrapped::expression(p)) + .unwrap()?; + // expr.expression() + // Ok(expr.expression()) + Ok(expr) // Ok(bx(Expr::BoolLit(false))) } |