12 files changed, 257 insertions, 85 deletions

diff --git a/grammar.ron b/grammar.ron
index fe0ec8406..70e269e20 100644
--- a/grammar.ron
+++ b/grammar.ron
@@ -16,6 +16,7 @@ Grammar(
         "self",
         "super",
         "in",
+        "where",
     ],
     tokens: [
         "ERROR",
@@ -73,7 +74,8 @@ Grammar(
     nodes: [
         "FILE",
         "STRUCT_ITEM",
-        "STRUCT_FIELD",
+        "NAMED_FIELD",
+        "POS_FIELD",
         "FN_ITEM",
         "EXTERN_CRATE_ITEM",
         "ATTR",
diff --git a/src/parser/event_parser/grammar/items.rs b/src/parser/event_parser/grammar/items.rs
index 2f64111ab..a14f6de77 100644
--- a/src/parser/event_parser/grammar/items.rs
+++ b/src/parser/event_parser/grammar/items.rs
@@ -56,8 +56,84 @@ fn item(p: &mut Parser) -> bool {
 }
 
 fn struct_item(p: &mut Parser) {
-    p.expect(IDENT)
-        && p.curly_block(|p| comma_list(p, EOF, struct_field));
+    if !p.expect(IDENT) {
+        return
+    }
+    generic_parameters(p);
+    match p.current() {
+        WHERE_KW => {
+            where_clause(p);
+            match p.current() {
+                SEMI => {
+                    p.bump();
+                    return
+                }
+                L_CURLY => named_fields(p),
+                _ => { //TODO: special case `(` error message
+                    p.error()
+                        .message("expected `;` or `{`")
+                        .emit();
+                    return
+                }
+            }
+        }
+        SEMI => {
+            p.bump();
+            return
+        }
+        L_CURLY => named_fields(p),
+        L_PAREN => {
+            tuple_fields(p);
+            p.expect(SEMI);
+        },
+        _ => {
+            p.error()
+                .message("expected `;`, `{`, or `(`")
+                .emit();
+            return
+        }
+    }
+}
+
+fn named_fields(p: &mut Parser) {
+    p.curly_block(|p| comma_list(p, EOF, |p| {
+        named_field(p);
+        true
+    }));
+
+    fn named_field(p: &mut Parser) {
+        node(p, NAMED_FIELD, |p| {
+            visibility(p);
+            p.expect(IDENT) && p.expect(COLON) && {
+                types::type_ref(p);
+                true
+            };
+        })
+    }
+}
+
+fn tuple_fields(p: &mut Parser) {
+    if !p.expect(L_PAREN) {
+        return
+    }
+    comma_list(p, R_PAREN, |p| {
+        tuple_field(p);
+        true
+    });
+    p.expect(R_PAREN);
+
+    fn tuple_field(p: &mut Parser) {
+        node(p, POS_FIELD, |p| {
+            visibility(p);
+            types::type_ref(p);
+        })
+    }
+}
+
+fn generic_parameters(_: &mut Parser) {
+}
+
+fn where_clause(_: &mut Parser) {
 }
 
 fn extern_crate_item(p: &mut Parser) {
@@ -133,11 +209,7 @@ fn use_item(p: &mut Parser) {
     }
 }
 
-fn struct_field(p: &mut Parser) -> bool {
-    node_if(p, IDENT, STRUCT_FIELD, |p| {
-        p.expect(COLON) && p.expect(IDENT);
-    })
-}
+
 
 fn fn_item(p: &mut Parser) {
     p.expect(IDENT) && p.expect(L_PAREN) && p.expect(R_PAREN)
diff --git a/src/parser/event_parser/grammar/mod.rs b/src/parser/event_parser/grammar/mod.rs
index 1c57e0cb4..881bb3ef3 100644
--- a/src/parser/event_parser/grammar/mod.rs
+++ b/src/parser/event_parser/grammar/mod.rs
@@ -6,6 +6,7 @@ use syntax_kinds::*;
 mod items;
 mod attributes;
 mod expressions;
+mod types;
 mod paths;
 
 pub(crate) fn file(p: &mut Parser) {
@@ -72,12 +73,21 @@ fn many<F: FnMut(&mut Parser) -> bool>(p: &mut Parser, mut f: F) {
 
 fn comma_list<F: Fn(&mut Parser) -> bool>(p: &mut Parser, end: SyntaxKind, f: F) {
     many(p, |p| {
-        if !f(p) || p.current() == end {
-            false
+        if p.current() == end {
+            return false
+        }
+        let pos = p.pos();
+        f(p);
+        if p.pos() == pos {
+            return false
+        }
+
+        if p.current() == end {
+            p.eat(COMMA);
         } else {
             p.expect(COMMA);
-            true
         }
+         true
     })
 }
 
diff --git a/src/parser/event_parser/grammar/types.rs b/src/parser/event_parser/grammar/types.rs
new file mode 100644
index 000000000..c431643d7
--- /dev/null
+++ b/src/parser/event_parser/grammar/types.rs
@@ -0,0 +1,5 @@
+use super::*;
+
+pub(super) fn type_ref(p: &mut Parser) {
+    p.expect(IDENT);
+}
\ No newline at end of file
diff --git a/src/syntax_kinds.rs b/src/syntax_kinds.rs
index 8bc63a210..5ab8b934b 100644
--- a/src/syntax_kinds.rs
+++ b/src/syntax_kinds.rs
@@ -17,74 +17,76 @@ pub const PUB_KW: SyntaxKind = SyntaxKind(12);
 pub const SELF_KW: SyntaxKind = SyntaxKind(13);
 pub const SUPER_KW: SyntaxKind = SyntaxKind(14);
 pub const IN_KW: SyntaxKind = SyntaxKind(15);
-pub const ERROR: SyntaxKind = SyntaxKind(16);
-pub const IDENT: SyntaxKind = SyntaxKind(17);
-pub const UNDERSCORE: SyntaxKind = SyntaxKind(18);
-pub const WHITESPACE: SyntaxKind = SyntaxKind(19);
-pub const INT_NUMBER: SyntaxKind = SyntaxKind(20);
-pub const FLOAT_NUMBER: SyntaxKind = SyntaxKind(21);
-pub const SEMI: SyntaxKind = SyntaxKind(22);
-pub const COMMA: SyntaxKind = SyntaxKind(23);
-pub const DOT: SyntaxKind = SyntaxKind(24);
-pub const DOTDOT: SyntaxKind = SyntaxKind(25);
-pub const DOTDOTDOT: SyntaxKind = SyntaxKind(26);
-pub const DOTDOTEQ: SyntaxKind = SyntaxKind(27);
-pub const L_PAREN: SyntaxKind = SyntaxKind(28);
-pub const R_PAREN: SyntaxKind = SyntaxKind(29);
-pub const L_CURLY: SyntaxKind = SyntaxKind(30);
-pub const R_CURLY: SyntaxKind = SyntaxKind(31);
-pub const L_BRACK: SyntaxKind = SyntaxKind(32);
-pub const R_BRACK: SyntaxKind = SyntaxKind(33);
-pub const L_ANGLE: SyntaxKind = SyntaxKind(34);
-pub const R_ANGLE: SyntaxKind = SyntaxKind(35);
-pub const AT: SyntaxKind = SyntaxKind(36);
-pub const POUND: SyntaxKind = SyntaxKind(37);
-pub const TILDE: SyntaxKind = SyntaxKind(38);
-pub const QUESTION: SyntaxKind = SyntaxKind(39);
-pub const COLON: SyntaxKind = SyntaxKind(40);
-pub const COLONCOLON: SyntaxKind = SyntaxKind(41);
-pub const DOLLAR: SyntaxKind = SyntaxKind(42);
-pub const EQ: SyntaxKind = SyntaxKind(43);
-pub const EQEQ: SyntaxKind = SyntaxKind(44);
-pub const FAT_ARROW: SyntaxKind = SyntaxKind(45);
-pub const NEQ: SyntaxKind = SyntaxKind(46);
-pub const EXCL: SyntaxKind = SyntaxKind(47);
-pub const LIFETIME: SyntaxKind = SyntaxKind(48);
-pub const CHAR: SyntaxKind = SyntaxKind(49);
-pub const BYTE: SyntaxKind = SyntaxKind(50);
-pub const STRING: SyntaxKind = SyntaxKind(51);
-pub const RAW_STRING: SyntaxKind = SyntaxKind(52);
-pub const BYTE_STRING: SyntaxKind = SyntaxKind(53);
-pub const RAW_BYTE_STRING: SyntaxKind = SyntaxKind(54);
-pub const PLUS: SyntaxKind = SyntaxKind(55);
-pub const MINUS: SyntaxKind = SyntaxKind(56);
-pub const STAR: SyntaxKind = SyntaxKind(57);
-pub const SLASH: SyntaxKind = SyntaxKind(58);
-pub const CARET: SyntaxKind = SyntaxKind(59);
-pub const PERCENT: SyntaxKind = SyntaxKind(60);
-pub const AMPERSAND: SyntaxKind = SyntaxKind(61);
-pub const PIPE: SyntaxKind = SyntaxKind(62);
-pub const THIN_ARROW: SyntaxKind = SyntaxKind(63);
-pub const COMMENT: SyntaxKind = SyntaxKind(64);
-pub const DOC_COMMENT: SyntaxKind = SyntaxKind(65);
-pub const SHEBANG: SyntaxKind = SyntaxKind(66);
-pub const FILE: SyntaxKind = SyntaxKind(67);
-pub const STRUCT_ITEM: SyntaxKind = SyntaxKind(68);
-pub const STRUCT_FIELD: SyntaxKind = SyntaxKind(69);
-pub const FN_ITEM: SyntaxKind = SyntaxKind(70);
-pub const EXTERN_CRATE_ITEM: SyntaxKind = SyntaxKind(71);
-pub const ATTR: SyntaxKind = SyntaxKind(72);
-pub const META_ITEM: SyntaxKind = SyntaxKind(73);
-pub const MOD_ITEM: SyntaxKind = SyntaxKind(74);
-pub const USE_ITEM: SyntaxKind = SyntaxKind(75);
-pub const USE_TREE: SyntaxKind = SyntaxKind(76);
-pub const PATH: SyntaxKind = SyntaxKind(77);
-pub const PATH_SEGMENT: SyntaxKind = SyntaxKind(78);
-pub const LITERAL: SyntaxKind = SyntaxKind(79);
-pub const ALIAS: SyntaxKind = SyntaxKind(80);
-pub const VISIBILITY: SyntaxKind = SyntaxKind(81);
+pub const WHERE_KW: SyntaxKind = SyntaxKind(16);
+pub const ERROR: SyntaxKind = SyntaxKind(17);
+pub const IDENT: SyntaxKind = SyntaxKind(18);
+pub const UNDERSCORE: SyntaxKind = SyntaxKind(19);
+pub const WHITESPACE: SyntaxKind = SyntaxKind(20);
+pub const INT_NUMBER: SyntaxKind = SyntaxKind(21);
+pub const FLOAT_NUMBER: SyntaxKind = SyntaxKind(22);
+pub const SEMI: SyntaxKind = SyntaxKind(23);
+pub const COMMA: SyntaxKind = SyntaxKind(24);
+pub const DOT: SyntaxKind = SyntaxKind(25);
+pub const DOTDOT: SyntaxKind = SyntaxKind(26);
+pub const DOTDOTDOT: SyntaxKind = SyntaxKind(27);
+pub const DOTDOTEQ: SyntaxKind = SyntaxKind(28);
+pub const L_PAREN: SyntaxKind = SyntaxKind(29);
+pub const R_PAREN: SyntaxKind = SyntaxKind(30);
+pub const L_CURLY: SyntaxKind = SyntaxKind(31);
+pub const R_CURLY: SyntaxKind = SyntaxKind(32);
+pub const L_BRACK: SyntaxKind = SyntaxKind(33);
+pub const R_BRACK: SyntaxKind = SyntaxKind(34);
+pub const L_ANGLE: SyntaxKind = SyntaxKind(35);
+pub const R_ANGLE: SyntaxKind = SyntaxKind(36);
+pub const AT: SyntaxKind = SyntaxKind(37);
+pub const POUND: SyntaxKind = SyntaxKind(38);
+pub const TILDE: SyntaxKind = SyntaxKind(39);
+pub const QUESTION: SyntaxKind = SyntaxKind(40);
+pub const COLON: SyntaxKind = SyntaxKind(41);
+pub const COLONCOLON: SyntaxKind = SyntaxKind(42);
+pub const DOLLAR: SyntaxKind = SyntaxKind(43);
+pub const EQ: SyntaxKind = SyntaxKind(44);
+pub const EQEQ: SyntaxKind = SyntaxKind(45);
+pub const FAT_ARROW: SyntaxKind = SyntaxKind(46);
+pub const NEQ: SyntaxKind = SyntaxKind(47);
+pub const EXCL: SyntaxKind = SyntaxKind(48);
+pub const LIFETIME: SyntaxKind = SyntaxKind(49);
+pub const CHAR: SyntaxKind = SyntaxKind(50);
+pub const BYTE: SyntaxKind = SyntaxKind(51);
+pub const STRING: SyntaxKind = SyntaxKind(52);
+pub const RAW_STRING: SyntaxKind = SyntaxKind(53);
+pub const BYTE_STRING: SyntaxKind = SyntaxKind(54);
+pub const RAW_BYTE_STRING: SyntaxKind = SyntaxKind(55);
+pub const PLUS: SyntaxKind = SyntaxKind(56);
+pub const MINUS: SyntaxKind = SyntaxKind(57);
+pub const STAR: SyntaxKind = SyntaxKind(58);
+pub const SLASH: SyntaxKind = SyntaxKind(59);
+pub const CARET: SyntaxKind = SyntaxKind(60);
+pub const PERCENT: SyntaxKind = SyntaxKind(61);
+pub const AMPERSAND: SyntaxKind = SyntaxKind(62);
+pub const PIPE: SyntaxKind = SyntaxKind(63);
+pub const THIN_ARROW: SyntaxKind = SyntaxKind(64);
+pub const COMMENT: SyntaxKind = SyntaxKind(65);
+pub const DOC_COMMENT: SyntaxKind = SyntaxKind(66);
+pub const SHEBANG: SyntaxKind = SyntaxKind(67);
+pub const FILE: SyntaxKind = SyntaxKind(68);
+pub const STRUCT_ITEM: SyntaxKind = SyntaxKind(69);
+pub const NAMED_FIELD: SyntaxKind = SyntaxKind(70);
+pub const POS_FIELD: SyntaxKind = SyntaxKind(71);
+pub const FN_ITEM: SyntaxKind = SyntaxKind(72);
+pub const EXTERN_CRATE_ITEM: SyntaxKind = SyntaxKind(73);
+pub const ATTR: SyntaxKind = SyntaxKind(74);
+pub const META_ITEM: SyntaxKind = SyntaxKind(75);
+pub const MOD_ITEM: SyntaxKind = SyntaxKind(76);
+pub const USE_ITEM: SyntaxKind = SyntaxKind(77);
+pub const USE_TREE: SyntaxKind = SyntaxKind(78);
+pub const PATH: SyntaxKind = SyntaxKind(79);
+pub const PATH_SEGMENT: SyntaxKind = SyntaxKind(80);
+pub const LITERAL: SyntaxKind = SyntaxKind(81);
+pub const ALIAS: SyntaxKind = SyntaxKind(82);
+pub const VISIBILITY: SyntaxKind = SyntaxKind(83);
 
-static INFOS: [SyntaxInfo; 82] = [
+static INFOS: [SyntaxInfo; 84] = [
     SyntaxInfo { name: "USE_KW" },
     SyntaxInfo { name: "FN_KW" },
     SyntaxInfo { name: "STRUCT_KW" },
@@ -101,6 +103,7 @@ static INFOS: [SyntaxInfo; 82] = [
     SyntaxInfo { name: "SELF_KW" },
     SyntaxInfo { name: "SUPER_KW" },
     SyntaxInfo { name: "IN_KW" },
+    SyntaxInfo { name: "WHERE_KW" },
     SyntaxInfo { name: "ERROR" },
     SyntaxInfo { name: "IDENT" },
     SyntaxInfo { name: "UNDERSCORE" },
@@ -154,7 +157,8 @@ static INFOS: [SyntaxInfo; 82] = [
     SyntaxInfo { name: "SHEBANG" },
     SyntaxInfo { name: "FILE" },
     SyntaxInfo { name: "STRUCT_ITEM" },
-    SyntaxInfo { name: "STRUCT_FIELD" },
+    SyntaxInfo { name: "NAMED_FIELD" },
+    SyntaxInfo { name: "POS_FIELD" },
     SyntaxInfo { name: "FN_ITEM" },
     SyntaxInfo { name: "EXTERN_CRATE_ITEM" },
     SyntaxInfo { name: "ATTR" },
@@ -191,6 +195,7 @@ pub(crate) fn ident_to_keyword(ident: &str) -> Option<SyntaxKind> {
        "self" => Some(SELF_KW),
        "super" => Some(SUPER_KW),
        "in" => Some(IN_KW),
+       "where" => Some(WHERE_KW),
        _ => None,
    }
 }
diff --git a/tests/data/lexer/0011_keywords.rs b/tests/data/lexer/0011_keywords.rs
index aa729cdbd..c2c9e5667 100644
--- a/tests/data/lexer/0011_keywords.rs
+++ b/tests/data/lexer/0011_keywords.rs
@@ -1 +1 @@
-fn use struct trait enum impl true false as extern crate mod pub self super in
+fn use struct trait enum impl true false as extern crate mod pub self super in where
diff --git a/tests/data/lexer/0011_keywords.txt b/tests/data/lexer/0011_keywords.txt
index 8a1f525ac..301ee21e2 100644
--- a/tests/data/lexer/0011_keywords.txt
+++ b/tests/data/lexer/0011_keywords.txt
@@ -29,4 +29,6 @@ WHITESPACE 1 " "
 SUPER_KW 5 "super"
 WHITESPACE 1 " "
 IN_KW 2 "in"
+WHITESPACE 1 " "
+WHERE_KW 5 "where"
 WHITESPACE 1 "\n"
diff --git a/tests/data/parser/err/0000_struct_field_missing_comma.txt b/tests/data/parser/err/0000_struct_field_missing_comma.txt
index 55a4ad915..f59205f55 100644
--- a/tests/data/parser/err/0000_struct_field_missing_comma.txt
+++ b/tests/data/parser/err/0000_struct_field_missing_comma.txt
@@ -5,7 +5,7 @@ FILE@[0; 34)
     IDENT@[7; 8)
     WHITESPACE@[8; 9)
     L_CURLY@[9; 10)
-    STRUCT_FIELD@[10; 26)
+    NAMED_FIELD@[10; 26)
       WHITESPACE@[10; 15)
       IDENT@[15; 16)
       COLON@[16; 17)
@@ -13,7 +13,7 @@ FILE@[0; 34)
       IDENT@[18; 21)
       WHITESPACE@[21; 26)
     err: `expected COMMA`
-    STRUCT_FIELD@[26; 33)
+    NAMED_FIELD@[26; 33)
       IDENT@[26; 27)
       COLON@[27; 28)
       WHITESPACE@[28; 29)
diff --git a/tests/data/parser/err/0003_C++_semicolon.txt b/tests/data/parser/err/0003_C++_semicolon.txt
index 9308bb330..8dd45d2e5 100644
--- a/tests/data/parser/err/0003_C++_semicolon.txt
+++ b/tests/data/parser/err/0003_C++_semicolon.txt
@@ -5,14 +5,14 @@ FILE@[0; 40)
     IDENT@[7; 8)
     WHITESPACE@[8; 9)
     L_CURLY@[9; 10)
-    STRUCT_FIELD@[10; 21)
+    NAMED_FIELD@[10; 21)
       WHITESPACE@[10; 15)
       IDENT@[15; 16)
       COLON@[16; 17)
       WHITESPACE@[17; 18)
       IDENT@[18; 21)
     COMMA@[21; 22)
-    STRUCT_FIELD@[22; 36)
+    NAMED_FIELD@[22; 36)
       WHITESPACE@[22; 27)
       IDENT@[27; 28)
       COLON@[28; 29)
diff --git a/tests/data/parser/ok/0002_struct_item_field.txt b/tests/data/parser/ok/0002_struct_item_field.txt
index 87ab3f7a9..58042f6a7 100644
--- a/tests/data/parser/ok/0002_struct_item_field.txt
+++ b/tests/data/parser/ok/0002_struct_item_field.txt
@@ -5,7 +5,7 @@ FILE@[0; 25)
     IDENT@[7; 8)
     WHITESPACE@[8; 9)
     L_CURLY@[9; 10)
-    STRUCT_FIELD@[10; 24)
+    NAMED_FIELD@[10; 24)
       WHITESPACE@[10; 15)
       IDENT@[15; 18)
       COLON@[18; 19)
diff --git a/tests/data/parser/ok/0016_struct_flavors.rs b/tests/data/parser/ok/0016_struct_flavors.rs
new file mode 100644
index 000000000..69638350c
--- /dev/null
+++ b/tests/data/parser/ok/0016_struct_flavors.rs
@@ -0,0 +1,10 @@
+struct A;
+struct B {}
+struct C();
+
+struct D {
+    a: u32,
+    pub b: u32
+}
+
+struct E(pub x, y,);
diff --git a/tests/data/parser/ok/0016_struct_flavors.txt b/tests/data/parser/ok/0016_struct_flavors.txt
new file mode 100644
index 000000000..93b16e1b9
--- /dev/null
+++ b/tests/data/parser/ok/0016_struct_flavors.txt
@@ -0,0 +1,66 @@
+FILE@[0; 97)
+  STRUCT_ITEM@[0; 10)
+    STRUCT_KW@[0; 6)
+    WHITESPACE@[6; 7)
+    IDENT@[7; 8)
+    SEMI@[8; 9)
+    WHITESPACE@[9; 10)
+  STRUCT_ITEM@[10; 22)
+    STRUCT_KW@[10; 16)
+    WHITESPACE@[16; 17)
+    IDENT@[17; 18)
+    WHITESPACE@[18; 19)
+    L_CURLY@[19; 20)
+    R_CURLY@[20; 21)
+    WHITESPACE@[21; 22)
+  STRUCT_ITEM@[22; 35)
+    STRUCT_KW@[22; 28)
+    WHITESPACE@[28; 29)
+    IDENT@[29; 30)
+    L_PAREN@[30; 31)
+    R_PAREN@[31; 32)
+    SEMI@[32; 33)
+    WHITESPACE@[33; 35)
+  STRUCT_ITEM@[35; 76)
+    STRUCT_KW@[35; 41)
+    WHITESPACE@[41; 42)
+    IDENT@[42; 43)
+    WHITESPACE@[43; 44)
+    L_CURLY@[44; 45)
+    NAMED_FIELD@[45; 56)
+      WHITESPACE@[45; 50)
+      IDENT@[50; 51)
+      COLON@[51; 52)
+      WHITESPACE@[52; 53)
+      IDENT@[53; 56)
+    COMMA@[56; 57)
+    NAMED_FIELD@[57; 73)
+      VISIBILITY@[57; 66)
+        WHITESPACE@[57; 62)
+        PUB_KW@[62; 65)
+        WHITESPACE@[65; 66)
+      IDENT@[66; 67)
+      COLON@[67; 68)
+      WHITESPACE@[68; 69)
+      IDENT@[69; 72)
+      WHITESPACE@[72; 73)
+    R_CURLY@[73; 74)
+    WHITESPACE@[74; 76)
+  STRUCT_ITEM@[76; 97)
+    STRUCT_KW@[76; 82)
+    WHITESPACE@[82; 83)
+    IDENT@[83; 84)
+    L_PAREN@[84; 85)
+    POS_FIELD@[85; 90)
+      VISIBILITY@[85; 89)
+        PUB_KW@[85; 88)
+        WHITESPACE@[88; 89)
+      IDENT@[89; 90)
+    COMMA@[90; 91)
+    POS_FIELD@[91; 93)
+      WHITESPACE@[91; 92)
+      IDENT@[92; 93)
+    COMMA@[93; 94)
+    R_PAREN@[94; 95)
+    SEMI@[95; 96)
+    WHITESPACE@[96; 97)