Merge #25

25: Drop curly_block r=matklad a=matklad

closes #13

Author: bors[bot]

src/parser/event_parser/grammar/items.rs

@@ -14,7 +14,7 @@ fn item(p: &mut Parser) {
     let item = p.start();
     attributes::outer_attributes(p);
     visibility(p);
-    let la = p.raw_lookahead(1);
+    let la = p.nth(1);
     let item_kind = match p.current() {
         EXTERN_KW if la == CRATE_KW => {
             extern_crate_item(p);
@@ -171,7 +171,7 @@ fn use_item(p: &mut Parser) {
     p.expect(SEMI);
 
     fn use_tree(p: &mut Parser) {
-        let la = p.raw_lookahead(1);
+        let la = p.nth(1);
         let m = p.start();
         match (p.current(), la) {
             (STAR, _) => {
@@ -235,5 +235,21 @@ fn fn_item(p: &mut Parser) {
     assert!(p.at(FN_KW));
     p.bump();
 
-    p.expect(IDENT) && p.expect(L_PAREN) && p.expect(R_PAREN) && p.curly_block(|_| ());
+    p.expect(IDENT);
+    if p.at(L_PAREN) {
+        fn_value_parameters(p);
+    } else {
+        p.error().message("expected function arguments").emit();
+    }
+
+    if p.at(L_CURLY) {
+        p.expect(L_CURLY);
+        p.expect(R_CURLY);
+    }
+
+    fn fn_value_parameters(p: &mut Parser) {
+        assert!(p.at(L_PAREN));
+        p.bump();
+        p.expect(R_PAREN);
+    }
 }

src/parser/event_parser/grammar/mod.rs

@@ -20,7 +20,7 @@ fn visibility(p: &mut Parser) {
         let vis = p.start();
         p.bump();
         if p.at(L_PAREN) {
-            match p.raw_lookahead(1) {
+            match p.nth(1) {
                 CRATE_KW | SELF_KW | SUPER_KW | IN_KW => {
                     p.bump();
                     if p.bump() == IN_KW {
@@ -57,7 +57,7 @@ impl<'p> Parser<'p> {
         err.complete(self, ERROR);
     }
 
-    pub(crate) fn expect(&mut self, kind: SyntaxKind) -> bool {
+    fn expect(&mut self, kind: SyntaxKind) -> bool {
         if self.at(kind) {
             self.bump();
             true
@@ -77,39 +77,23 @@ impl<'p> Parser<'p> {
 
 trait Lookahead: Copy {
     fn is_ahead(self, p: &Parser) -> bool;
-    fn consume(p: &mut Parser);
 }
 
 impl Lookahead for SyntaxKind {
     fn is_ahead(self, p: &Parser) -> bool {
         p.current() == self
     }
-
-    fn consume(p: &mut Parser) {
-        p.bump();
-    }
 }
 
 impl Lookahead for [SyntaxKind; 2] {
     fn is_ahead(self, p: &Parser) -> bool {
-        p.current() == self[0] && p.raw_lookahead(1) == self[1]
-    }
-
-    fn consume(p: &mut Parser) {
-        p.bump();
-        p.bump();
+        p.current() == self[0] && p.nth(1) == self[1]
     }
 }
 
 impl Lookahead for [SyntaxKind; 3] {
     fn is_ahead(self, p: &Parser) -> bool {
-        p.current() == self[0] && p.raw_lookahead(1) == self[1] && p.raw_lookahead(2) == self[2]
-    }
-
-    fn consume(p: &mut Parser) {
-        p.bump();
-        p.bump();
-        p.bump();
+        p.current() == self[0] && p.nth(1) == self[1] && p.nth(2) == self[2]
     }
 }
 
@@ -121,8 +105,4 @@ impl<'a> Lookahead for AnyOf<'a> {
         let curr = p.current();
         self.0.iter().any(|&k| k == curr)
     }
-
-    fn consume(p: &mut Parser) {
-        p.bump();
-    }
 }

src/parser/event_parser/grammar/paths.rs

@@ -12,7 +12,7 @@ pub(crate) fn use_path(p: &mut Parser) {
     path_segment(p, true);
     let mut qual = path.complete(p, PATH);
     loop {
-        if p.at(COLONCOLON) && !items::is_use_tree_start(p.raw_lookahead(1)) {
+        if p.at(COLONCOLON) && !items::is_use_tree_start(p.nth(1)) {
             let path = qual.precede(p);
             p.bump();
             path_segment(p, false);

src/parser/event_parser/parser.rs

@@ -1,7 +1,7 @@
 use {SyntaxKind, TextUnit, Token};
 use super::Event;
 use super::super::is_insignificant;
-use SyntaxKind::{EOF, ERROR, L_CURLY, R_CURLY, TOMBSTONE};
+use SyntaxKind::{EOF, TOMBSTONE};
 
 pub(crate) struct Marker {
     pos: u32,
@@ -106,9 +106,6 @@ pub(crate) struct Parser<'t> {
 
     pos: usize,
     events: Vec<Event>,
-
-    curly_level: i32,
-    curly_limit: Option<i32>,
 }
 
 impl<'t> Parser<'t> {
@@ -131,30 +128,14 @@ impl<'t> Parser<'t> {
 
             pos: 0,
             events: Vec::new(),
-            curly_level: 0,
-            curly_limit: None,
         }
     }
 
     pub(crate) fn into_events(self) -> Vec<Event> {
-        assert!(self.curly_limit.is_none());
         assert_eq!(self.current(), EOF);
         self.events
     }
 
-    pub(crate) fn current(&self) -> SyntaxKind {
-        if self.pos == self.tokens.len() {
-            return EOF;
-        }
-        let token = self.tokens[self.pos];
-        if let Some(limit) = self.curly_limit {
-            if limit == self.curly_level && token.kind == R_CURLY {
-                return EOF;
-            }
-        }
-        token.kind
-    }
-
     pub(crate) fn start(&mut self) -> Marker {
         let m = Marker {
             pos: self.events.len() as u32,
@@ -172,11 +153,8 @@ impl<'t> Parser<'t> {
 
     pub(crate) fn bump(&mut self) -> SyntaxKind {
         let kind = self.current();
-        match kind {
-            L_CURLY => self.curly_level += 1,
-            R_CURLY => self.curly_level -= 1,
-            EOF => return EOF,
-            _ => (),
+        if kind == EOF {
+            return EOF;
         }
         self.pos += 1;
         self.event(Event::Token {
@@ -186,30 +164,12 @@ impl<'t> Parser<'t> {
         kind
     }
 
-    pub(crate) fn raw_lookahead(&self, n: usize) -> SyntaxKind {
+    pub(crate) fn nth(&self, n: usize) -> SyntaxKind {
         self.tokens.get(self.pos + n).map(|t| t.kind).unwrap_or(EOF)
     }
 
-    pub(crate) fn curly_block<F: FnOnce(&mut Parser)>(&mut self, f: F) -> bool {
-        let old_level = self.curly_level;
-        let old_limit = self.curly_limit;
-        if !self.expect(L_CURLY) {
-            return false;
-        }
-        self.curly_limit = Some(self.curly_level);
-        f(self);
-        assert!(self.curly_level > old_level);
-        self.curly_limit = old_limit;
-        if !self.expect(R_CURLY) {
-            let err = self.start();
-            while self.curly_level > old_level {
-                if self.bump() == EOF {
-                    break;
-                }
-            }
-            err.complete(self, ERROR);
-        }
-        true
+    pub(crate) fn current(&self) -> SyntaxKind {
+        self.nth(0)
     }
 
     fn event(&mut self, event: Event) {