Remove rule aliasing

1 files changed, 93 insertions, 107 deletions

diff --git a/dhall_syntax/src/parser.rs b/dhall_syntax/src/parser.rs
index d11eb18..2debc8b 100644
--- a/dhall_syntax/src/parser.rs
+++ b/dhall_syntax/src/parser.rs
@@ -174,12 +174,11 @@ macro_rules! make_parser {
     );
     (@rule_alias,
         rule!(
-            $name:ident<$o:ty>
-            as $group:ident;
+            $name:ident<$o:ty>;
             $($args:tt)*
         )
     ) => ({
-        Rule::$group
+        Rule::$name
     });
     (@rule_alias,
         token_rule!($name:ident<$o:ty>)
@@ -190,8 +189,7 @@ macro_rules! make_parser {
     (@body,
         ($climbers:expr, $input:expr, $pair:expr),
         rule!(
-            $name:ident<$o:ty>
-            as $group:ident;
+            $name:ident<$o:ty>;
             $span:ident;
             captured_str!($x:pat) => $body:expr
         )
@@ -199,15 +197,14 @@ macro_rules! make_parser {
         let res: Result<_, String> = try {
             let $span = Span::make($input, $pair.as_span());
             let $x = $pair.as_str();
-            ParsedValue::$group($body)
+            ParsedValue::$name($body)
         };
         res.map_err(|msg| custom_parse_error(&$pair, msg))
     });
     (@body,
         ($climbers:expr, $input:expr, $pair:expr),
         rule!(
-            $name:ident<$o:ty>
-            as $group:ident;
+            $name:ident<$o:ty>;
             $span:ident;
             children!( $( [$($args:tt)*] => $body:expr ),* $(,)* )
         )
@@ -257,27 +254,33 @@ macro_rules! make_parser {
         };
 
         let res = res.map_err(|msg| custom_parse_error(&$pair, msg))?;
-        Ok(ParsedValue::$group(res))
+        Ok(ParsedValue::$name(res))
     });
     (@body,
         ($climbers:expr, $input:expr, $pair:expr),
         rule!(
-            $name:ident<$o:ty>
-            as $group:ident;
-            prec_climb!( $_climber:expr, $args:pat => $body:expr $(,)* )
+            $name:ident<$o:ty>;
+            prec_climb!($other_name:ident, $_climber:expr, $args:pat => $body:expr $(,)* )
         )
     ) => ({
-        let climber = $climbers.get(&Rule::$name).unwrap();
+        let climber = $climbers.get(&Rule::$name).expect(&format!("UUUU: {:?}", $climbers));
         climber.climb(
             $pair.clone().into_inner(),
-            |p| parse_any($climbers, $input.clone(), p),
+            |p| {
+                let parsed = parse_any($climbers, $input.clone(), p)?;
+                if let ParsedValue::$other_name(x) = parsed {
+                    Ok(ParsedValue::$name(x))
+                } else {
+                    unreachable!()
+                }
+            },
             |l, op, r| {
                 let (l, r) = (l?, r?);
                 let res: Result<_, String> = try {
                     #[allow(unused_imports)]
                     use ParsedValue::*;
                     match (l, op, r) {
-                        $args => ParsedValue::$group($body),
+                        $args => ParsedValue::$name($body),
                         children => Err(
                             format!("Unexpected children: {:?}", children)
                         )?,
@@ -289,26 +292,13 @@ macro_rules! make_parser {
     });
     (@body,
         ($($things:tt)*),
-        rule!( $name:ident<$o:ty>; $($args:tt)* )
-    ) => (
-        make_parser!(@body,
-            ($($things)*),
-            rule!( $name<$o> as $name; $($args)* )
-        )
-    );
-    (@body,
-        ($($things:tt)*),
-        rule!(
-            $name:ident<$o:ty>
-            as $group:ident;
-            $($args:tt)*
+        rule!( $name:ident<$o:ty>; $($args:tt)*
         )
     ) => ({
         make_parser!(@body,
             ($($things)*),
             rule!(
-                $name<$o>
-                as $group;
+                $name<$o>;
                 _span;
                 $($args)*
             )
@@ -324,9 +314,8 @@ macro_rules! make_parser {
     (@construct_climber,
         ($map:expr),
         rule!(
-            $name:ident<$o:ty>
-            as $group:ident;
-            prec_climb!( $climber:expr, $($_rest:tt)* )
+            $name:ident<$o:ty>;
+            prec_climb!( $other_name:ident, $climber:expr, $($_rest:tt)* )
         )
     ) => ({
         $map.insert(Rule::$name, $climber)
@@ -379,27 +368,8 @@ macro_rules! make_parser {
         fn parse_any<'a>(
             climbers: &HashMap<Rule, PrecClimber<Rule>>,
             input: Rc<str>,
-            mut pair: Pair<'a, Rule>,
+            pair: Pair<'a, Rule>,
         ) -> ParseResult<ParsedValue<'a>> {
-            // Avoid parsing while the pair has exactly one child that can be returned as-is
-            loop {
-                if can_be_shortcutted(pair.as_rule()) {
-                    let mut i = pair.clone().into_inner();
-                    let first = i.next();
-                    let second = i.next();
-                    match (first, second) {
-                        // If pair has exactly one child, just go on parsing that child
-                        (Some(p), None) => {
-                            pair = p;
-                            continue;
-                        }
-                        // Otherwise parse normally
-                        _ => break,
-                    }
-                }
-                break;
-            }
-
             match pair.as_rule() {
                 $(
                     Rule::$name => Parsers::$name(climbers, input, pair),
@@ -418,20 +388,6 @@ fn do_parse<'a>(
     parse_any(&climbers, input, pair)
 }
 
-// List of rules that can be shortcutted if they have a single child
-fn can_be_shortcutted(rule: Rule) -> bool {
-    use Rule::*;
-    match rule {
-        expression
-        | operator_expression
-        | application_expression
-        | first_application_expression
-        | selector_expression
-        | annotated_expression => true,
-        _ => false,
-    }
-}
-
 // Trim the shared indent off of a vec of lines, as defined by the Dhall semantics of multiline
 // literals.
 fn trim_indent(lines: &mut Vec<ParsedText>) {
@@ -591,10 +547,10 @@ make_parser! {
     rule!(single_quote_char<&'a str>;
         captured_str!(s) => s
     );
-    rule!(escaped_quote_pair<&'a str> as single_quote_char;
+    rule!(escaped_quote_pair<&'a str>;
         captured_str!(_) => "''"
     );
-    rule!(escaped_interpolation<&'a str> as single_quote_char;
+    rule!(escaped_interpolation<&'a str>;
         captured_str!(_) => "${"
     );
     rule!(interpolation<ParsedSubExpr>; children!(
@@ -609,6 +565,20 @@ make_parser! {
             lines.last_mut().unwrap().push(c);
             lines
         },
+        [escaped_quote_pair(c), single_quote_continue(lines)] => {
+            let mut lines = lines;
+            // TODO: don't allocate for every char
+            let c = InterpolatedTextContents::Text(c.to_owned());
+            lines.last_mut().unwrap().push(c);
+            lines
+        },
+        [escaped_interpolation(c), single_quote_continue(lines)] => {
+            let mut lines = lines;
+            // TODO: don't allocate for every char
+            let c = InterpolatedTextContents::Text(c.to_owned());
+            lines.last_mut().unwrap().push(c);
+            lines
+        },
         [single_quote_char(c), single_quote_continue(lines)] => {
             let mut lines = lines;
             if c == "\n" || c == "\r\n" {
@@ -682,7 +652,7 @@ make_parser! {
         }
     );
 
-    rule!(identifier<ParsedSubExpr> as expression; span; children!(
+    rule!(identifier<ParsedSubExpr>; span; children!(
         [variable(v)] => {
             spanned(span, Var(v))
         },
@@ -715,19 +685,22 @@ make_parser! {
     ));
 
     rule!(local<(FilePrefix, Vec<String>)>; children!(
-        [local(l)] => l
+        [parent_path(l)] => l,
+        [here_path(l)] => l,
+        [home_path(l)] => l,
+        [absolute_path(l)] => l,
     ));
 
-    rule!(parent_path<(FilePrefix, Vec<String>)> as local; children!(
+    rule!(parent_path<(FilePrefix, Vec<String>)>; children!(
         [path(p)] => (FilePrefix::Parent, p)
     ));
-    rule!(here_path<(FilePrefix, Vec<String>)> as local; children!(
+    rule!(here_path<(FilePrefix, Vec<String>)>; children!(
         [path(p)] => (FilePrefix::Here, p)
     ));
-    rule!(home_path<(FilePrefix, Vec<String>)> as local; children!(
+    rule!(home_path<(FilePrefix, Vec<String>)>; children!(
         [path(p)] => (FilePrefix::Home, p)
     ));
-    rule!(absolute_path<(FilePrefix, Vec<String>)> as local; children!(
+    rule!(absolute_path<(FilePrefix, Vec<String>)>; children!(
         [path(p)] => (FilePrefix::Absolute, p)
     ));
 
@@ -760,7 +733,7 @@ make_parser! {
 
     rule!(http<URL<ParsedSubExpr>>; children!(
         [http_raw(url)] => url,
-        [http_raw(url), expression(e)] =>
+        [http_raw(url), import_expression(e)] =>
             URL { headers: Some(e), ..url },
     ));
 
@@ -828,7 +801,7 @@ make_parser! {
     token_rule!(Text<()>);
     token_rule!(Location<()>);
 
-    rule!(import<ParsedSubExpr> as expression; span; children!(
+    rule!(import<ParsedSubExpr>; span; children!(
         [import_hashed(imp)] => {
             spanned(span, Import(crate::Import {
                 mode: ImportMode::Code,
@@ -857,13 +830,13 @@ make_parser! {
     token_rule!(if_<()>);
     token_rule!(in_<()>);
 
-    rule!(empty_list_literal<ParsedSubExpr> as expression; span; children!(
-        [expression(e)] => {
+    rule!(empty_list_literal<ParsedSubExpr>; span; children!(
+        [application_expression(e)] => {
             spanned(span, EmptyListLit(e))
         },
     ));
 
-    rule!(expression<ParsedSubExpr> as expression; span; children!(
+    rule!(expression<ParsedSubExpr>; span; children!(
         [lambda(()), label(l), expression(typ),
                 arrow(()), expression(body)] => {
             spanned(span, Lam(l, typ, body))
@@ -881,16 +854,17 @@ make_parser! {
                 arrow(()), expression(body)] => {
             spanned(span, Pi(l, typ, body))
         },
-        [expression(typ), arrow(()), expression(body)] => {
+        [operator_expression(typ), arrow(()), expression(body)] => {
             spanned(span, Pi("_".into(), typ, body))
         },
-        [merge(()), expression(x), expression(y), expression(z)] => {
+        [merge(()), import_expression(x), import_expression(y), application_expression(z)] => {
             spanned(span, Merge(x, y, Some(z)))
         },
+        [empty_list_literal(e)] => e,
         [assert(()), expression(x)] => {
             spanned(span, Assert(x))
         },
-        [expression(e)] => e,
+        [annotated_expression(e)] => e,
     ));
 
     rule!(let_binding<(Label, Option<ParsedSubExpr>, ParsedSubExpr)>;
@@ -904,14 +878,14 @@ make_parser! {
     token_rule!(List<()>);
     token_rule!(Optional<()>);
 
-    rule!(annotated_expression<ParsedSubExpr> as expression; span; children!(
-        [expression(e)] => e,
-        [expression(e), expression(annot)] => {
+    rule!(annotated_expression<ParsedSubExpr>; span; children!(
+        [operator_expression(e)] => e,
+        [operator_expression(e), expression(annot)] => {
             spanned(span, Annot(e, annot))
         },
     ));
 
-    rule!(operator_expression<ParsedSubExpr> as expression; prec_climb!(
+    rule!(operator_expression<ParsedSubExpr>; prec_climb!(application_expression,
         {
             use Rule::*;
             // In order of precedence
@@ -937,7 +911,7 @@ make_parser! {
                     .collect(),
             )
         },
-        (expression(l), op, expression(r)) => {
+        (operator_expression(l), op, operator_expression(r)) => {
             use crate::BinOp::*;
             use Rule::*;
             let op = match op.as_rule() {
@@ -966,32 +940,38 @@ make_parser! {
     token_rule!(Some_<()>);
     token_rule!(toMap<()>);
 
-    rule!(application_expression<ParsedSubExpr> as expression; children!(
-        [expression(e)] => e,
-        [expression(first), expression(rest)..] => {
+    rule!(application_expression<ParsedSubExpr>; children!(
+        [first_application_expression(e)] => e,
+        [first_application_expression(first), import_expression(rest)..] => {
             rest.fold(first, |acc, e| unspanned(App(acc, e)))
         },
     ));
 
-    rule!(first_application_expression<ParsedSubExpr> as expression; span;
+    rule!(first_application_expression<ParsedSubExpr>; span;
             children!(
-        [expression(e)] => e,
-        [Some_(()), expression(e)] => {
+        [Some_(()), import_expression(e)] => {
             spanned(span, SomeLit(e))
         },
-        [merge(()), expression(x), expression(y)] => {
+        [merge(()), import_expression(x), import_expression(y)] => {
             spanned(span, Merge(x, y, None))
         },
+        [import_expression(e)] => e,
     ));
 
-    rule!(selector_expression<ParsedSubExpr> as expression; children!(
-        [expression(e)] => e,
-        [expression(first), selector(rest)..] => {
+    rule!(import_expression<ParsedSubExpr>; span;
+            children!(
+        [selector_expression(e)] => e,
+        [import(e)] => e,
+    ));
+
+    rule!(selector_expression<ParsedSubExpr>; children!(
+        [primitive_expression(e)] => e,
+        [primitive_expression(first), selector(rest)..] => {
             rest.fold(first, |acc, e| unspanned(match e {
                 Either::Left(l) => Field(acc, l),
                 Either::Right(ls) => Projection(acc, ls),
             }))
-        }
+        },
     ));
 
     rule!(selector<Either<Label, DupTreeSet<Label>>>; children!(
@@ -1004,24 +984,30 @@ make_parser! {
         [label(ls)..] => ls.collect(),
     ));
 
-    rule!(primitive_expression<ParsedSubExpr> as expression; span; children!(
+    rule!(primitive_expression<ParsedSubExpr>; span; children!(
         [double_literal(n)] => spanned(span, DoubleLit(n)),
         [natural_literal(n)] => spanned(span, NaturalLit(n)),
         [integer_literal(n)] => spanned(span, IntegerLit(n)),
         [double_quote_literal(s)] => spanned(span, TextLit(s)),
         [single_quote_literal(s)] => spanned(span, TextLit(s)),
+        [empty_record_type(e)] => e,
+        [empty_record_literal(e)] => e,
+        [non_empty_record_type_or_literal(e)] => e,
+        [union_type(e)] => e,
+        [non_empty_list_literal(e)] => e,
+        [identifier(e)] => e,
         [expression(e)] => e,
     ));
 
-    rule!(empty_record_literal<ParsedSubExpr> as expression; span;
+    rule!(empty_record_literal<ParsedSubExpr>; span;
         captured_str!(_) => spanned(span, RecordLit(Default::default()))
     );
 
-    rule!(empty_record_type<ParsedSubExpr> as expression; span;
+    rule!(empty_record_type<ParsedSubExpr>; span;
         captured_str!(_) => spanned(span, RecordType(Default::default()))
     );
 
-    rule!(non_empty_record_type_or_literal<ParsedSubExpr> as expression; span;
+    rule!(non_empty_record_type_or_literal<ParsedSubExpr>; span;
           children!(
         [label(first_label), non_empty_record_type(rest)] => {
             let (first_expr, mut map) = rest;
@@ -1057,7 +1043,7 @@ make_parser! {
         [label(name), expression(expr)] => (name, expr)
     ));
 
-    rule!(union_type<ParsedSubExpr> as expression; span; children!(
+    rule!(union_type<ParsedSubExpr>; span; children!(
         [empty_union_type(_)] => {
             spanned(span, UnionType(Default::default()))
         },
@@ -1073,7 +1059,7 @@ make_parser! {
         [label(name)] => (name, None),
     ));
 
-    rule!(non_empty_list_literal<ParsedSubExpr> as expression; span;
+    rule!(non_empty_list_literal<ParsedSubExpr>; span;
           children!(
         [expression(items)..] => spanned(
             span,
@@ -1081,7 +1067,7 @@ make_parser! {
         )
     ));
 
-    rule!(final_expression<ParsedSubExpr> as expression; children!(
+    rule!(final_expression<ParsedSubExpr>; children!(
         [expression(e), EOI(_eoi)] => e
     ));
 }
@@ -1092,7 +1078,7 @@ pub fn parse_expr(s: &str) -> ParseResult<ParsedSubExpr> {
     let expr = do_parse(rc_input, pairs.next().unwrap())?;
     assert_eq!(pairs.next(), None);
     match expr {
-        ParsedValue::expression(e) => Ok(e),
+        ParsedValue::final_expression(e) => Ok(e),
         _ => unreachable!(),
     }
 }