Drop more high-order stuff

5 files changed, 100 insertions, 93 deletions

diff --git a/src/parser/event_parser/grammar/attributes.rs b/src/parser/event_parser/grammar/attributes.rs
index a896b4901..8b5e5bcfe 100644
--- a/src/parser/event_parser/grammar/attributes.rs
+++ b/src/parser/event_parser/grammar/attributes.rs
@@ -1,5 +1,6 @@
 use super::*;
 
+#[derive(PartialEq, Eq)]
 enum AttrKind {
     Inner, Outer
 }
@@ -14,18 +15,27 @@ pub(super) fn outer_attributes(p: &mut Parser) {
 
 
 fn attribute(p: &mut Parser, kind: AttrKind) -> bool {
-    fn attr_tail(p: &mut Parser) {
-        meta_item(p) && p.expect(R_BRACK);
-    }
-
-    match kind {
-        AttrKind::Inner => node_if(p, [POUND, EXCL, L_BRACK], ATTR, attr_tail),
-        AttrKind::Outer => node_if(p, [POUND, L_BRACK], ATTR, attr_tail),
+    if p.at(POUND) {
+        if kind == AttrKind::Inner && p.raw_lookahead(1) != EXCL {
+            return false;
+        }
+        p.start(ATTR);
+        p.bump();
+        if kind == AttrKind::Inner {
+            p.bump();
+        }
+        p.expect(L_BRACK) && meta_item(p) && p.expect(R_BRACK);
+        p.finish();
+        true
+    } else {
+        false
     }
 }
 
 fn meta_item(p: &mut Parser) -> bool {
-    node_if(p, IDENT, META_ITEM, |p| {
+    if p.at(IDENT) {
+        p.start(META_ITEM);
+        p.bump();
         if p.eat(EQ) {
             if !expressions::literal(p) {
                 p.error()
@@ -36,7 +46,12 @@ fn meta_item(p: &mut Parser) -> bool {
             comma_list(p, R_PAREN, meta_item_inner);
             p.expect(R_PAREN);
         }
-    })
+        p.finish();
+        true
+    } else {
+        false
+    }
+
 }
 
 fn meta_item_inner(p: &mut Parser) -> bool {
diff --git a/src/parser/event_parser/grammar/expressions.rs b/src/parser/event_parser/grammar/expressions.rs
index f40a3cce2..0f65193c9 100644
--- a/src/parser/event_parser/grammar/expressions.rs
+++ b/src/parser/event_parser/grammar/expressions.rs
@@ -1,11 +1,16 @@
 use super::*;
 
 pub(super) fn literal(p: &mut Parser) -> bool {
-    let literals = [
-        TRUE_KW, FALSE_KW,
-        INT_NUMBER, FLOAT_NUMBER,
-        BYTE, CHAR,
-        STRING, RAW_STRING, BYTE_STRING, RAW_BYTE_STRING,
-    ];
-    node_if(p, AnyOf(&literals), LITERAL, |_| ())
-}
\ No newline at end of file
+    match p.current() {
+        TRUE_KW | FALSE_KW |
+        INT_NUMBER | FLOAT_NUMBER |
+        BYTE | CHAR |
+        STRING | RAW_STRING | BYTE_STRING | RAW_BYTE_STRING => {
+            p.start(LITERAL);
+            p.bump();
+            p.finish();
+            true
+        }
+        _ => false
+    }
+}
diff --git a/src/parser/event_parser/grammar/items.rs b/src/parser/event_parser/grammar/items.rs
index f96f4cc9c..4514f0dab 100644
--- a/src/parser/event_parser/grammar/items.rs
+++ b/src/parser/event_parser/grammar/items.rs
@@ -7,7 +7,7 @@ pub(super) fn mod_contents(p: &mut Parser) {
     }
 }
 
-fn item(p: &mut Parser){
+fn item(p: &mut Parser) {
     let attrs_start = p.mark();
     attributes::outer_attributes(p);
     visibility(p);
@@ -51,7 +51,7 @@ fn struct_item(p: &mut Parser) {
     fn struct_inner(p: &mut Parser) {
         if !p.expect(IDENT) {
             p.finish();
-            return
+            return;
         }
         generic_parameters(p);
         match p.current() {
@@ -60,31 +60,31 @@ fn struct_item(p: &mut Parser) {
                 match p.current() {
                     SEMI => {
                         p.bump();
-                        return
+                        return;
                     }
                     L_CURLY => named_fields(p),
                     _ => { //TODO: special case `(` error message
                         p.error()
                             .message("expected `;` or `{`")
                             .emit();
-                        return
+                        return;
                     }
                 }
             }
             SEMI => {
                 p.bump();
-                return
+                return;
             }
             L_CURLY => named_fields(p),
             L_PAREN => {
                 tuple_fields(p);
                 p.expect(SEMI);
-            },
+            }
             _ => {
                 p.error()
                     .message("expected `;`, `{`, or `(`")
                     .emit();
-                return
+                return;
             }
         }
     }
@@ -108,7 +108,7 @@ fn named_fields(p: &mut Parser) {
 
 fn tuple_fields(p: &mut Parser) {
     if !p.expect(L_PAREN) {
-        return
+        return;
     }
     comma_list(p, R_PAREN, |p| {
         tuple_field(p);
@@ -124,11 +124,9 @@ fn tuple_fields(p: &mut Parser) {
     }
 }
 
-fn generic_parameters(_: &mut Parser) {
-}
+fn generic_parameters(_: &mut Parser) {}
 
-fn where_clause(_: &mut Parser) {
-}
+fn where_clause(_: &mut Parser) {}
 
 fn extern_crate_item(p: &mut Parser) {
     p.start(EXTERN_CRATE_ITEM);
@@ -168,24 +166,29 @@ fn use_item(p: &mut Parser) {
     p.expect(SEMI);
     p.finish();
 
-    fn use_tree(p: &mut Parser) -> bool{
-        if node_if(p, STAR, USE_TREE, |_| ()) {
-            return true
-        }
-        if node_if(p, [COLONCOLON, STAR], USE_TREE, |_| ()) {
-           return true
-        }
-        if [COLONCOLON, L_CURLY].is_ahead(p) || L_CURLY.is_ahead(p) {
-            node(p, USE_TREE, |p| {
-                p.eat(COLONCOLON);
+    fn use_tree(p: &mut Parser) -> bool {
+        let la = p.raw_lookahead(1);
+        match (p.current(), la) {
+            (STAR, _) => {
+                p.start(USE_TREE);
+                p.bump();
+            }
+            (COLONCOLON, STAR) => {
+                p.start(USE_TREE);
+                p.bump();
+                p.bump();
+            }
+            (L_CURLY, _) | (COLONCOLON, L_CURLY) => {
+                p.start(USE_TREE);
+                if p.at(COLONCOLON) {
+                    p.bump();
+                }
                 p.curly_block(|p| {
                     comma_list(p, EOF, use_tree);
                 });
-            });
-            return true;
-        }
-        if paths::is_path_start(p) {
-            node(p, USE_TREE, |p| {
+            }
+            _ if paths::is_path_start(p) => {
+                p.start(USE_TREE);
                 paths::use_path(p);
                 match p.current() {
                     AS_KW => {
@@ -212,15 +215,15 @@ fn use_item(p: &mut Parser) {
                     }
                     _ => (),
                 }
-            });
-            return true;
+            }
+            _ => return false,
         }
-        false
+        p.finish();
+        return true;
     }
 }
 
 
-
 fn fn_item(p: &mut Parser) {
     p.start(FN_ITEM);
 
diff --git a/src/parser/event_parser/grammar/mod.rs b/src/parser/event_parser/grammar/mod.rs
index 0c775bb25..c3d0c8c10 100644
--- a/src/parser/event_parser/grammar/mod.rs
+++ b/src/parser/event_parser/grammar/mod.rs
@@ -46,21 +46,6 @@ fn alias(p: &mut Parser) -> bool {
     true //FIXME: return false if three are errors
 }
 
-fn node_if<F: FnOnce(&mut Parser), L: Lookahead>(
-    p: &mut Parser,
-    first: L,
-    node_kind: SyntaxKind,
-    rest: F
-) -> bool {
-    first.is_ahead(p) && { node(p, node_kind, |p| { L::consume(p); rest(p); }); true }
-}
-
-fn node<F: FnOnce(&mut Parser)>(p: &mut Parser, node_kind: SyntaxKind, rest: F) {
-    p.start(node_kind);
-    rest(p);
-    p.finish();
-}
-
 fn repeat<F: FnMut(&mut Parser) -> bool>(p: &mut Parser, mut f: F) {
     loop {
         let pos = p.pos();
diff --git a/src/parser/event_parser/grammar/paths.rs b/src/parser/event_parser/grammar/paths.rs
index 45f3cb779..f5124cfce 100644
--- a/src/parser/event_parser/grammar/paths.rs
+++ b/src/parser/event_parser/grammar/paths.rs
@@ -1,6 +1,6 @@
 use super::*;
 
-pub (crate) fn is_path_start(p: &Parser) -> bool {
+pub(crate) fn is_path_start(p: &Parser) -> bool {
     AnyOf(&[IDENT, SELF_KW, SUPER_KW, COLONCOLON]).is_ahead(p)
 }
 
@@ -9,39 +9,38 @@ pub(crate) fn use_path(p: &mut Parser) {
         return;
     }
     let mut prev = p.mark();
-    node(p, PATH, |p| {
-        path_segment(p, true);
-    });
-    repeat(p, |p| {
+    p.start(PATH);
+    path_segment(p, true);
+    p.finish();
+    loop {
         let curr = p.mark();
-        if p.current() == COLONCOLON && !items::is_use_tree_start(p.raw_lookahead(1)) {
-            node(p, PATH, |p| {
-                p.bump();
-                path_segment(p, false);
-                p.forward_parent(prev, curr);
-                prev = curr;
-            });
-            true
+        if p.at(COLONCOLON) && !items::is_use_tree_start(p.raw_lookahead(1)) {
+            p.start(PATH);
+            p.bump();
+            path_segment(p, false);
+            p.forward_parent(prev, curr);
+            prev = curr;
+            p.finish();
         } else {
-            false
+            break;
         }
-    });
+    }
 }
 
 fn path_segment(p: &mut Parser, first: bool) {
-    node(p, PATH_SEGMENT, |p| {
-        if first {
-            p.eat(COLONCOLON);
+    p.start(PATH_SEGMENT);
+    if first {
+        p.eat(COLONCOLON);
+    }
+    match p.current() {
+        IDENT | SELF_KW | SUPER_KW => {
+            p.bump();
         }
-        match p.current() {
-            IDENT | SELF_KW | SUPER_KW => {
-                p.bump();
-            },
-            _ => {
-                p.error()
-                    .message("expected identifier")
-                    .emit();
-            }
-        };
-    })
-}
\ No newline at end of file
+        _ => {
+            p.error()
+                .message("expected identifier")
+                .emit();
+        }
+    };
+    p.finish();
+}