G: some attributes

grammar.ron

@@ -66,5 +66,6 @@ Grammar(
         "STRUCT_FIELD",
         "FN_ITEM",
         "ATTR",
+        "META_ITEM",
     ]
 )

src/parser/event_parser/grammar.rs

@@ -34,7 +34,7 @@ fn item(p: &mut Parser) {
 
 fn struct_item(p: &mut Parser) {
     p.expect(IDENT)
-        && p.curly_block(|p| comma_list(p, struct_field));
+        && p.curly_block(|p| comma_list(p, EOF, struct_field));
 }
 
 fn struct_field(p: &mut Parser) -> bool {
@@ -52,19 +52,45 @@ fn fn_item(p: &mut Parser) {
 // Paths, types, attributes, and stuff //
 
 fn inner_attributes(p: &mut Parser) {
-    many(p, inner_attribute)
+    many(p, |p| attribute(p, true))
 }
 
-fn inner_attribute(p: &mut Parser) -> bool {
+fn attribute(p: &mut Parser, inner: bool) -> bool {
-    if !(p.lookahead(&[EXCL, POUND])) {
+    let attr_start = inner && p.lookahead(&[POUND, EXCL, L_BRACK])
+        || !inner && p.lookahead(&[POUND, L_BRACK]);
+    if !attr_start {
         return false;
     }
     node(p, ATTR, |p| {
-        p.bump_n(2);
+        p.bump_n(if inner { 3 } else { 2 });
+        meta_item(p) && p.expect(R_BRACK);
     });
     true
 }
 
+fn meta_item(p: &mut Parser) -> bool {
+    node_if(p, IDENT, META_ITEM, |p| {
+        if p.eat(EQ) {
+            if !literal(p) {
+                p.error()
+                    .message("expected literal")
+                    .emit();
+            }
+        } else if p.eat(L_PAREN) {
+            comma_list(p, R_PAREN, meta_item_inner);
+            p.expect(R_PAREN);
+        }
+    })
+}
+
+fn meta_item_inner(p: &mut Parser) -> bool {
+    meta_item(p) || literal(p)
+}
+
+fn literal(p: &mut Parser) -> bool {
+    p.eat(INT_NUMBER) || p.eat(FLOAT_NUMBER)
+}
+
 fn outer_attributes(_: &mut Parser) {
 }
 
@@ -75,7 +101,12 @@ 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 {
+fn node_if<F: FnOnce(&mut Parser)>(
+    p: &mut Parser,
+    first: SyntaxKind,
+    node_kind: SyntaxKind,
+    rest: F
+) -> bool {
     p.current() == first && { node(p, node_kind, |p| { p.bump(); rest(p); }); true }
 }
 
@@ -89,10 +120,9 @@ fn many<F: Fn(&mut Parser) -> bool>(p: &mut Parser, f: F) {
     while f(p) { }
 }
 
-fn comma_list<F: Fn(&mut Parser) -> bool>(p: &mut Parser, f: F) {
+fn comma_list<F: Fn(&mut Parser) -> bool>(p: &mut Parser, end: SyntaxKind, f: F) {
     many(p, |p| {
-        f(p);
+        if !f(p) || p.current() == end {
-        if p.current() == EOF {
             false
         } else {
             p.expect(COMMA);
@@ -157,4 +187,8 @@ impl<'p> Parser<'p> {
             self.bump();
         }
     }
+
+    fn eat(&mut self, kind: SyntaxKind) -> bool {
+        self.current() == kind && { self.bump(); true }
+    }
 }

src/syntax_kinds.rs

@@ -63,8 +63,9 @@ pub const STRUCT_ITEM: SyntaxKind = SyntaxKind(58);
 pub const STRUCT_FIELD: SyntaxKind = SyntaxKind(59);
 pub const FN_ITEM: SyntaxKind = SyntaxKind(60);
 pub const ATTR: SyntaxKind = SyntaxKind(61);
+pub const META_ITEM: SyntaxKind = SyntaxKind(62);
 
-static INFOS: [SyntaxInfo; 62] = [
+static INFOS: [SyntaxInfo; 63] = [
     SyntaxInfo { name: "USE_KW" },
     SyntaxInfo { name: "FN_KW" },
     SyntaxInfo { name: "STRUCT_KW" },
@@ -127,6 +128,7 @@ static INFOS: [SyntaxInfo; 62] = [
     SyntaxInfo { name: "STRUCT_FIELD" },
     SyntaxInfo { name: "FN_ITEM" },
     SyntaxInfo { name: "ATTR" },
+    SyntaxInfo { name: "META_ITEM" },
 ];
 
 pub(crate) fn syntax_info(kind: SyntaxKind) -> &'static SyntaxInfo {

tests/data/parser/ok/0006_inner_attributes.txt

@@ -1,44 +1,58 @@
 FILE@[0; 236)
-  ERROR@[0; 236)
+  ATTR@[0; 9)
-  err: `expected item`
     POUND@[0; 1)
     EXCL@[1; 2)
     L_BRACK@[2; 3)
+    META_ITEM@[3; 7)
       IDENT@[3; 7)
     R_BRACK@[7; 8)
     WHITESPACE@[8; 9)
+  ATTR@[9; 24)
     POUND@[9; 10)
     EXCL@[10; 11)
     L_BRACK@[11; 12)
+    META_ITEM@[12; 22)
       IDENT@[12; 16)
       L_PAREN@[16; 17)
+      META_ITEM@[17; 21)
         IDENT@[17; 21)
       R_PAREN@[21; 22)
     R_BRACK@[22; 23)
     WHITESPACE@[23; 24)
+  ATTR@[24; 40)
     POUND@[24; 25)
     EXCL@[25; 26)
     L_BRACK@[26; 27)
+    META_ITEM@[27; 38)
       IDENT@[27; 31)
       L_PAREN@[31; 32)
+      META_ITEM@[32; 37)
         IDENT@[32; 37)
       R_PAREN@[37; 38)
     R_BRACK@[38; 39)
     WHITESPACE@[39; 40)
+  ATTR@[40; 66)
     POUND@[40; 41)
     EXCL@[41; 42)
     L_BRACK@[42; 43)
+    META_ITEM@[43; 66)
       IDENT@[43; 47)
       L_PAREN@[47; 48)
+      META_ITEM@[48; 53)
         IDENT@[48; 53)
       COMMA@[53; 54)
       WHITESPACE@[54; 55)
       INT_NUMBER@[55; 58)
       COMMA@[58; 59)
+      META_ITEM@[59; 64)
         WHITESPACE@[59; 60)
         IDENT@[60; 64)
       COMMA@[64; 65)
+      err: `expected R_PAREN`
       WHITESPACE@[65; 66)
+    err: `expected R_BRACK`
+  ERROR@[66; 236)
+  err: `expected item`
     STRING@[66; 72)
     COMMA@[72; 73)
     WHITESPACE@[73; 74)