Move parsing of field pattern lists to the parser (where it belongs)

crates/ra_hir/src/expr.rs

@@ -857,11 +857,19 @@ impl ExprCollector {
                 let fields = p
                     .field_pat_list()
                     .expect("every struct should have a field list")
-                    .field_pats()
-                    .into_iter()
+                    .pats()
                     .map(|f| {
-                        let name = Name::new(f.ident);
-                        let pat = self.collect_pat(&*f.pat);
+                        let ast_pat = f.pat().expect("field pat always contains a pattern");
+                        let pat = self.collect_pat(ast_pat);
+                        let name = f
+                            .name()
+                            .unwrap_or_else(|| {
+                                ast::BindPat::cast(ast_pat.syntax())
+                                    .expect("field pat without label is a bind pat")
+                                    .name()
+                                    .expect("bind pat has a name")
+                            })
+                            .as_name();
                         FieldPat { name, pat }
                     })
                     .collect();

crates/ra_syntax/src/ast.rs

@@ -664,55 +664,6 @@ impl LiteralExpr {
     }
 }
 
-#[derive(Clone, Debug, PartialEq, Eq, Hash)]
-pub struct FieldPat {
-    pub ident: SmolStr,
-    // FIXME: could we use a regular reference?
-    pub pat: TreeArc<Pat>,
-}
-
-impl FieldPatList {
-    // TODO: try returning an iterator?
-    // FIXME: shouldnt the parser do this? :o
-    pub fn field_pats(&self) -> Vec<FieldPat> {
-        let mut child_iter = self.syntax().children();
-        let mut pats = Vec::new();
-
-        while let Some(node) = child_iter.next() {
-            let kind = node.kind();
-            if kind != IDENT && kind != BIND_PAT {
-                continue;
-            }
-
-            let ident = if let Some(text) = node.leaf_text() {
-                text.clone()
-            } else {
-                SmolStr::new(node.text().to_string())
-            };
-            let mut pat = Pat::cast(node).map(AstNode::to_owned);
-
-            // get pat
-            while let Some(node) = child_iter.next() {
-                if node.kind() == COMMA {
-                    break;
-                }
-
-                if let Some(p) = Pat::cast(node) {
-                    pat = Some(p.to_owned());
-                }
-            }
-
-            let field_pat = FieldPat {
-                ident: ident,
-                pat: pat.unwrap(),
-            };
-            pats.push(field_pat);
-        }
-
-        pats
-    }
-}
-
 impl BindPat {
     pub fn is_mutable(&self) -> bool {
         self.syntax().children().any(|n| n.kind() == MUT_KW)

crates/ra_syntax/src/ast/generated.rs

@@ -858,6 +858,35 @@ impl FieldExpr {
     }
 }
 
+// FieldPat
+#[derive(Debug, PartialEq, Eq, Hash)]
+#[repr(transparent)]
+pub struct FieldPat {
+    pub(crate) syntax: SyntaxNode,
+}
+unsafe impl TransparentNewType for FieldPat {
+    type Repr = rowan::SyntaxNode<RaTypes>;
+}
+
+impl AstNode for FieldPat {
+    fn cast(syntax: &SyntaxNode) -> Option<&Self> {
+        match syntax.kind() {
+            FIELD_PAT => Some(FieldPat::from_repr(syntax.into_repr())),
+            _ => None,
+        }
+    }
+    fn syntax(&self) -> &SyntaxNode { &self.syntax }
+    fn to_owned(&self) -> TreeArc<FieldPat> { TreeArc::cast(self.syntax.to_owned()) }
+}
+
+
+impl ast::NameOwner for FieldPat {}
+impl FieldPat {
+    pub fn pat(&self) -> Option<&Pat> {
+        super::child_opt(self)
+    }
+}
+
 // FieldPatList
 #[derive(Debug, PartialEq, Eq, Hash)]
 #[repr(transparent)]
@@ -880,7 +909,11 @@ impl AstNode for FieldPatList {
 }
 
 
-impl FieldPatList {}
+impl FieldPatList {
+    pub fn pats(&self) -> impl Iterator<Item = &FieldPat> {
+        super::children(self)
+    }
+}
 
 // FloatNumber
 #[derive(Debug, PartialEq, Eq, Hash)]

crates/ra_syntax/src/grammar.ron

@@ -154,6 +154,7 @@ Grammar(
         "PATH_PAT",
         "STRUCT_PAT",
         "FIELD_PAT_LIST",
+        "FIELD_PAT",
         "TUPLE_STRUCT_PAT",
         "TUPLE_PAT",
         "SLICE_PAT",
@@ -495,7 +496,11 @@ Grammar(
         "PlaceholderPat": (),
         "PathPat": ( options: [ "Path" ] ),
         "StructPat": ( options: ["FieldPatList", "Path"] ),
-        "FieldPatList": (),
+        "FieldPatList": ( collections: [["pats", "FieldPat"]] ),
+        "FieldPat": (
+            traits: ["NameOwner"],
+            options: ["Pat"]
+        ),
         "TupleStructPat": (
             options: ["Path"],
             collections: [["args", "Pat"]],

crates/ra_syntax/src/grammar/patterns.rs

@@ -128,15 +128,7 @@ fn field_pat_list(p: &mut Parser) {
     while !p.at(EOF) && !p.at(R_CURLY) {
         match p.current() {
             DOTDOT => p.bump(),
-            IDENT if p.nth(1) == COLON => {
-                p.bump();
-                p.bump();
-                pattern(p);
-            }
-            L_CURLY => error_block(p, "expected ident"),
-            _ => {
-                bind_pat(p, false);
-            }
+            _ => field_pat(p),
         }
         if !p.at(R_CURLY) {
             p.expect(COMMA);
@@ -146,6 +138,22 @@ fn field_pat_list(p: &mut Parser) {
     m.complete(p, FIELD_PAT_LIST);
 }
 
+fn field_pat(p: &mut Parser) {
+    let m = p.start();
+    match p.current() {
+        IDENT if p.nth(1) == COLON => {
+            name(p);
+            p.bump();
+            pattern(p);
+        }
+        L_CURLY => error_block(p, "expected ident"),
+        _ => {
+            bind_pat(p, false);
+        }
+    }
+    m.complete(p, FIELD_PAT);
+}
+
 // test placeholder_pat
 // fn main() { let _ = (); }
 fn placeholder_pat(p: &mut Parser) -> CompletedMarker {

crates/ra_syntax/src/syntax_kinds/generated.rs

@@ -152,6 +152,7 @@ pub enum SyntaxKind {
     PATH_PAT,
     STRUCT_PAT,
     FIELD_PAT_LIST,
+    FIELD_PAT,
     TUPLE_STRUCT_PAT,
     TUPLE_PAT,
     SLICE_PAT,
@@ -414,6 +415,7 @@ impl SyntaxKind {
             PATH_PAT => &SyntaxInfo { name: "PATH_PAT" },
             STRUCT_PAT => &SyntaxInfo { name: "STRUCT_PAT" },
             FIELD_PAT_LIST => &SyntaxInfo { name: "FIELD_PAT_LIST" },
+            FIELD_PAT => &SyntaxInfo { name: "FIELD_PAT" },
             TUPLE_STRUCT_PAT => &SyntaxInfo { name: "TUPLE_STRUCT_PAT" },
             TUPLE_PAT => &SyntaxInfo { name: "TUPLE_PAT" },
             SLICE_PAT => &SyntaxInfo { name: "SLICE_PAT" },