Introduce EOF token

3 files changed, 136 insertions, 140 deletions

diff --git a/src/parser/event_parser/grammar.rs b/src/parser/event_parser/grammar.rs
index f676a183c..64c6718cb 100644
--- a/src/parser/event_parser/grammar.rs
+++ b/src/parser/event_parser/grammar.rs
@@ -1,5 +1,6 @@
 use super::parser::Parser;
 use {SyntaxKind};
+use tree::EOF;
 use syntax_kinds::*;
 
 // Items //
@@ -18,11 +19,7 @@ pub(crate) fn file(p: &mut Parser) {
 }
 
 fn item_first(p: &Parser) -> bool {
-    let current = match p.current() {
-        Some(c) => c,
-        None => return false,
-    };
-    match current {
+    match p.current() {
         STRUCT_KW | FN_KW => true,
         _ => false,
     }
@@ -79,7 +76,7 @@ fn visibility(_: &mut Parser) {
 // Error recovery and high-order utils //
 
 fn node_if<F: FnOnce(&mut Parser)>(p: &mut Parser, first: SyntaxKind, node_kind: SyntaxKind, rest: F) -> bool {
-    p.current_is(first) && { node(p, node_kind, |p| { p.bump(); rest(p); }); true }
+    p.current() == first && { node(p, node_kind, |p| { p.bump(); rest(p); }); true }
 }
 
 fn node<F: FnOnce(&mut Parser)>(p: &mut Parser, node_kind: SyntaxKind, rest: F) {
@@ -95,7 +92,7 @@ fn many<F: Fn(&mut Parser) -> bool>(p: &mut Parser, f: F) {
 fn comma_list<F: Fn(&mut Parser) -> bool>(p: &mut Parser, f: F) {
     many(p, |p| {
         f(p);
-        if p.is_eof() {
+        if p.current() == EOF {
             false
         } else {
             p.expect(COMMA);
@@ -119,7 +116,7 @@ where
             f(p);
             return true;
         }
-        if p.is_eof() {
+        if p.current() == EOF {
             if skipped {
                 p.finish();
             }
@@ -131,18 +128,14 @@ where
                 .message(message)
                 .emit();
         }
-        p.bump().unwrap();
+        p.bump();
         skipped = true;
     }
 }
 
 impl<'p> Parser<'p> {
-    fn current_is(&self, kind: SyntaxKind) -> bool {
-        self.current() == Some(kind)
-    }
-
     pub(crate) fn expect(&mut self, kind: SyntaxKind) -> bool {
-        if self.current_is(kind) {
+        if self.current() == kind {
             self.bump();
             true
         } else {
@@ -154,7 +147,7 @@ impl<'p> Parser<'p> {
     }
 
     fn optional(&mut self, kind: SyntaxKind) {
-        if self.current_is(kind) {
+        if self.current() == kind {
             self.bump();
         }
     }
diff --git a/src/parser/event_parser/parser.rs b/src/parser/event_parser/parser.rs
index f0d1d358b..bec9dbab4 100644
--- a/src/parser/event_parser/parser.rs
+++ b/src/parser/event_parser/parser.rs
@@ -2,8 +2,7 @@ use {Token, SyntaxKind, TextUnit};
 use super::{Event};
 use super::super::is_insignificant;
 use syntax_kinds::{L_CURLY, R_CURLY, ERROR};
-
-pub(crate) const EOF: SyntaxKind = SyntaxKind(10000);
+use tree::EOF;
 
 
 pub(crate) struct Parser<'t> {
@@ -46,19 +45,22 @@ impl<'t> Parser<'t> {
     }
 
     pub(crate) fn into_events(self) -> Vec<Event> {
-        assert!(self.is_eof());
+        assert!(self.curly_limit.is_none());
+        assert!(self.current() == EOF);
         self.events
     }
 
-    pub(crate) fn is_eof(&self) -> bool {
+    pub(crate) fn current(&self) -> SyntaxKind {
         if self.pos == self.tokens.len() {
-            return true
+            return EOF;
         }
+        let token = self.tokens[self.pos];
         if let Some(limit) = self.curly_limit {
-            let token = self.tokens[self.pos];
-            return limit == self.curly_level && token.kind == R_CURLY;
+            if limit == self.curly_level && token.kind == R_CURLY {
+                return EOF
+            }
         }
-        false
+        token.kind
     }
 
     pub(crate) fn start(&mut self, kind: SyntaxKind) {
@@ -73,24 +75,17 @@ impl<'t> Parser<'t> {
         ErrorBuilder::new(self)
     }
 
-    pub(crate) fn current(&self) -> Option<SyntaxKind> {
-        if self.is_eof() {
-            return None;
-        }
-        let token = self.tokens[self.pos];
-        Some(token.kind)
-    }
-
-    pub(crate) fn bump(&mut self) -> Option<SyntaxKind> {
-        let kind = self.current()?;
+    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,
             _ => (),
         }
         self.pos += 1;
         self.event(Event::Token { kind, n_raw_tokens: 1 });
-        Some(kind)
+        kind
     }
 
     pub(crate) fn lookahead(&self, kinds: &[SyntaxKind]) -> bool {
@@ -114,7 +109,7 @@ impl<'t> Parser<'t> {
         if !self.expect(R_CURLY) {
             self.start(ERROR);
             while self.curly_level > old_level {
-                if self.bump().is_none() {
+                if self.bump() == EOF {
                     break;
                 }
             }
diff --git a/src/tree/mod.rs b/src/tree/mod.rs
index 7f4d427ba..d8f843737 100644
--- a/src/tree/mod.rs
+++ b/src/tree/mod.rs
@@ -10,8 +10,16 @@ pub use self::file_builder::{FileBuilder, Sink};
 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub struct SyntaxKind(pub(crate) u32);
 
+pub(crate) const EOF: SyntaxKind = SyntaxKind(10000);
+pub(crate) const EOF_INFO: SyntaxInfo = SyntaxInfo {
+    name: "EOF"
+};
+
 impl SyntaxKind {
     fn info(self) -> &'static SyntaxInfo {
+        if self == EOF {
+            return &EOF_INFO;
+        }
         syntax_info(self)
     }
 }
@@ -35,72 +43,72 @@ pub struct Token {
 }
 
 pub struct File {
-        text: String,
-        nodes: Vec<NodeData>,
-        errors: Vec<SyntaxErrorData>,
+    text: String,
+    nodes: Vec<NodeData>,
+    errors: Vec<SyntaxErrorData>,
 }
 
 impl File {
-        pub fn root<'f>(&'f self) -> Node<'f> {
-                assert!(!self.nodes.is_empty());
-                Node { file: self, idx: NodeIdx(0) }
-        }
+    pub fn root<'f>(&'f self) -> Node<'f> {
+        assert!(!self.nodes.is_empty());
+        Node { file: self, idx: NodeIdx(0) }
+    }
 }
 
 #[derive(Clone, Copy)]
 pub struct Node<'f> {
-        file: &'f File,
-        idx: NodeIdx,
+    file: &'f File,
+    idx: NodeIdx,
 }
 
 impl<'f> Node<'f> {
-        pub fn kind(&self) -> SyntaxKind {
-                self.data().kind
-        }
+    pub fn kind(&self) -> SyntaxKind {
+        self.data().kind
+    }
 
-        pub fn range(&self) -> TextRange {
-                self.data().range
-        }
+    pub fn range(&self) -> TextRange {
+        self.data().range
+    }
 
-        pub fn text(&self) -> &'f str {
-                &self.file.text.as_str()[self.range()]
-        }
+    pub fn text(&self) -> &'f str {
+        &self.file.text.as_str()[self.range()]
+    }
 
-        pub fn parent(&self) -> Option<Node<'f>> {
-                self.as_node(self.data().parent)
-        }
+    pub fn parent(&self) -> Option<Node<'f>> {
+        self.as_node(self.data().parent)
+    }
 
-        pub fn children(&self) -> Children<'f> {
-                Children { next: self.as_node(self.data().first_child) }
-        }
+    pub fn children(&self) -> Children<'f> {
+        Children { next: self.as_node(self.data().first_child) }
+    }
 
-        pub fn errors(&self) -> SyntaxErrors<'f> {
-                let pos = self.file.errors.iter().position(|e| e.node == self.idx);
-                let next = pos
-                        .map(|i| ErrorIdx(i as u32))
-                        .map(|idx| SyntaxError { file: self.file, idx });
-                SyntaxErrors { next }
-        }
+    pub fn errors(&self) -> SyntaxErrors<'f> {
+        let pos = self.file.errors.iter().position(|e| e.node == self.idx);
+        let next = pos
+            .map(|i| ErrorIdx(i as u32))
+            .map(|idx| SyntaxError { file: self.file, idx });
+        SyntaxErrors { next }
+    }
 
-        fn data(&self) -> &'f NodeData {
-                &self.file.nodes[self.idx]
-        }
+    fn data(&self) -> &'f NodeData {
+        &self.file.nodes[self.idx]
+    }
 
-        fn as_node(&self, idx: Option<NodeIdx>) -> Option<Node<'f>> {
-                idx.map(|idx| Node { file: self.file, idx })
-        }
+    fn as_node(&self, idx: Option<NodeIdx>) -> Option<Node<'f>> {
+        idx.map(|idx| Node { file: self.file, idx })
+    }
 }
 
 impl<'f> fmt::Debug for Node<'f> {
-        fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
-                write!(fmt, "{:?}@{:?}", self.kind(), self.range())
-        }
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        write!(fmt, "{:?}@{:?}", self.kind(), self.range())
+    }
 }
 
 impl<'f> cmp::PartialEq<Node<'f>> for Node<'f> {
-        fn eq(&self, other: &Node<'f>) -> bool {
-                self.idx == other.idx && ::std::ptr::eq(self.file, other.file)
-        }
+    fn eq(&self, other: &Node<'f>) -> bool {
+        self.idx == other.idx && ::std::ptr::eq(self.file, other.file)
+    }
 }
 
 impl<'f> cmp::Eq for Node<'f> {
@@ -108,66 +116,66 @@ impl<'f> cmp::Eq for Node<'f> {
 
 #[derive(Clone, Copy)]
 pub struct SyntaxError<'f> {
-        file: &'f File,
-        idx: ErrorIdx,
+    file: &'f File,
+    idx: ErrorIdx,
 }
 
 impl<'f> SyntaxError<'f> {
-        pub fn message(&self) -> &'f str {
-                self.data().message.as_str()
-        }
-
-        pub fn after_child(&self) -> Option<Node<'f>> {
-                let idx = self.data().after_child?;
-                Some(Node { file: self.file, idx })
-        }
-
-        fn data(&self) -> &'f SyntaxErrorData {
-                &self.file.errors[self.idx]
-        }
-
-        fn next(&self) -> Option<SyntaxError<'f>> {
-                let next_idx = self.idx.0 + 1;
-                if !((next_idx as usize) < self.file.errors.len()) {
-                        return None;
-                }
-                let result = SyntaxError {
-                        file: self.file,
-                        idx: ErrorIdx(next_idx)
-                };
-                if result.data().node != self.data().node {
-                        return None;
-                }
-                Some(result)
-        }
+    pub fn message(&self) -> &'f str {
+        self.data().message.as_str()
+    }
+
+    pub fn after_child(&self) -> Option<Node<'f>> {
+        let idx = self.data().after_child?;
+        Some(Node { file: self.file, idx })
+    }
+
+    fn data(&self) -> &'f SyntaxErrorData {
+        &self.file.errors[self.idx]
+    }
+
+    fn next(&self) -> Option<SyntaxError<'f>> {
+        let next_idx = self.idx.0 + 1;
+        if !((next_idx as usize) < self.file.errors.len()) {
+            return None;
+        }
+        let result = SyntaxError {
+            file: self.file,
+            idx: ErrorIdx(next_idx)
+        };
+        if result.data().node != self.data().node {
+            return None;
+        }
+        Some(result)
+    }
 }
 
 pub struct Children<'f> {
-        next: Option<Node<'f>>,
+    next: Option<Node<'f>>,
 }
 
 impl<'f> Iterator for Children<'f> {
-        type Item = Node<'f>;
+    type Item = Node<'f>;
 
-        fn next(&mut self) -> Option<Node<'f>> {
-                let next = self.next;
-                self.next = next.and_then(|node| node.as_node(node.data().next_sibling));
-                next
-        }
+    fn next(&mut self) -> Option<Node<'f>> {
+        let next = self.next;
+        self.next = next.and_then(|node| node.as_node(node.data().next_sibling));
+        next
+    }
 }
 
 pub struct SyntaxErrors<'f> {
-        next: Option<SyntaxError<'f>>,
+    next: Option<SyntaxError<'f>>,
 }
 
 impl<'f> Iterator for SyntaxErrors<'f> {
-        type Item = SyntaxError<'f>;
+    type Item = SyntaxError<'f>;
 
-        fn next(&mut self) -> Option<SyntaxError<'f>> {
-                let next = self.next;
-                self.next = next.as_ref().and_then(SyntaxError::next);
-                next
-        }
+    fn next(&mut self) -> Option<SyntaxError<'f>> {
+        let next = self.next;
+        self.next = next.as_ref().and_then(SyntaxError::next);
+        next
+    }
 }
 
 
@@ -175,40 +183,40 @@ impl<'f> Iterator for SyntaxErrors<'f> {
 struct NodeIdx(u32);
 
 struct NodeData {
-        kind: SyntaxKind,
-        range: TextRange,
-        parent: Option<NodeIdx>,
-        first_child: Option<NodeIdx>,
-        next_sibling: Option<NodeIdx>,
+    kind: SyntaxKind,
+    range: TextRange,
+    parent: Option<NodeIdx>,
+    first_child: Option<NodeIdx>,
+    next_sibling: Option<NodeIdx>,
 }
 
 impl ::std::ops::Index<NodeIdx> for Vec<NodeData> {
-        type Output = NodeData;
+    type Output = NodeData;
 
-        fn index(&self, NodeIdx(idx): NodeIdx) -> &NodeData {
-                &self[idx as usize]
-        }
+    fn index(&self, NodeIdx(idx): NodeIdx) -> &NodeData {
+        &self[idx as usize]
+    }
 }
 
 impl ::std::ops::IndexMut<NodeIdx> for Vec<NodeData> {
-        fn index_mut(&mut self, NodeIdx(idx): NodeIdx) -> &mut NodeData {
-                &mut self[idx as usize]
-        }
+    fn index_mut(&mut self, NodeIdx(idx): NodeIdx) -> &mut NodeData {
+        &mut self[idx as usize]
+    }
 }
 
 #[derive(Clone, Copy)]
 struct ErrorIdx(u32);
 
 struct SyntaxErrorData {
-        node: NodeIdx,
-        message: String,
-        after_child: Option<NodeIdx>,
+    node: NodeIdx,
+    message: String,
+    after_child: Option<NodeIdx>,
 }
 
 impl ::std::ops::Index<ErrorIdx> for Vec<SyntaxErrorData> {
-        type Output = SyntaxErrorData;
+    type Output = SyntaxErrorData;
 
-        fn index(&self, ErrorIdx(idx): ErrorIdx) -> &SyntaxErrorData {
-                &self[idx as usize]
-        }
+    fn index(&self, ErrorIdx(idx): ErrorIdx) -> &SyntaxErrorData {
+        &self[idx as usize]
+    }
 }