Merge #3955

3955: Align grammar for record patterns and literals r=matklad a=matklad

The grammar now looks like this

   [name_ref :] pat



bors r+
🤖

Co-authored-by: Aleksey Kladov <aleksey.kladov@gmail.com>

crates/ra_assists/src/handlers/reorder_fields.rs

@@ -1,20 +1,20 @@
 use std::collections::HashMap;
 
-use itertools::Itertools;
-
 use hir::{Adt, ModuleDef, PathResolution, Semantics, Struct};
+use itertools::Itertools;
 use ra_ide_db::RootDatabase;
 use ra_syntax::{
-    algo, ast,
-    ast::{Name, Path, RecordLit, RecordPat},
-    AstNode, SyntaxKind, SyntaxNode,
+    algo,
+    ast::{self, Path, RecordLit, RecordPat},
+    match_ast, AstNode, SyntaxKind,
+    SyntaxKind::*,
+    SyntaxNode,
 };
 
 use crate::{
     assist_ctx::{Assist, AssistCtx},
     AssistId,
 };
-use ra_syntax::ast::{Expr, NameRef};
 
 // Assist: reorder_fields
 //
@@ -59,7 +59,6 @@ fn reorder<R: AstNode>(ctx: AssistCtx) -> Option<Assist> {
 }
 
 fn get_fields_kind(node: &SyntaxNode) -> Vec<SyntaxKind> {
-    use SyntaxKind::*;
     match node.kind() {
         RECORD_LIT => vec![RECORD_FIELD],
         RECORD_PAT => vec![RECORD_FIELD_PAT, BIND_PAT],
@@ -68,19 +67,14 @@ fn get_fields_kind(node: &SyntaxNode) -> Vec<SyntaxKind> {
 }
 
 fn get_field_name(node: &SyntaxNode) -> String {
-    use SyntaxKind::*;
-    match node.kind() {
-        RECORD_FIELD => {
-            if let Some(name) = node.children().find_map(NameRef::cast) {
-                return name.to_string();
-            }
-            node.children().find_map(Expr::cast).map(|expr| expr.to_string()).unwrap_or_default()
-        }
-        BIND_PAT | RECORD_FIELD_PAT => {
-            node.children().find_map(Name::cast).map(|n| n.to_string()).unwrap_or_default()
-        }
-        _ => String::new(),
+    let res = match_ast! {
+        match node {
+            ast::RecordField(field) => { field.field_name().map(|it| it.to_string()) },
+            ast::RecordFieldPat(field) => { field.field_name().map(|it| it.to_string()) },
+            _ => None,
         }
+    };
+    res.unwrap_or_default()
 }
 
 fn get_fields(record: &SyntaxNode) -> Vec<SyntaxNode> {

crates/ra_hir_def/src/body/lower.rs

@@ -637,7 +637,7 @@ impl ExprCollector<'_> {
                 let iter = record_field_pat_list.record_field_pats().filter_map(|f| {
                     let ast_pat = f.pat()?;
                     let pat = self.collect_pat(ast_pat);
-                    let name = f.name()?.as_name();
+                    let name = f.field_name()?.as_name();
                     Some(RecordFieldPat { name, pat })
                 });
                 fields.extend(iter);

crates/ra_hir_expand/src/name.rs

@@ -83,6 +83,15 @@ impl AsName for ast::Name {
     }
 }
 
+impl AsName for ast::NameOrNameRef {
+    fn as_name(&self) -> Name {
+        match self {
+            ast::NameOrNameRef::Name(it) => it.as_name(),
+            ast::NameOrNameRef::NameRef(it) => it.as_name(),
+        }
+    }
+}
+
 impl AsName for tt::Ident {
     fn as_name(&self) -> Name {
         Name::resolve(&self.text)

crates/ra_hir_ty/src/tests/patterns.rs

@@ -1,7 +1,8 @@
-use super::{infer, infer_with_mismatches};
 use insta::assert_snapshot;
 use test_utils::covers;
 
+use super::{infer, infer_with_mismatches};
+
 #[test]
 fn infer_pattern() {
     assert_snapshot!(

crates/ra_ide/src/completion/complete_pattern.rs

@@ -7,6 +7,10 @@ pub(super) fn complete_pattern(acc: &mut Completions, ctx: &CompletionContext) {
     if !ctx.is_pat_binding_or_const {
         return;
     }
+    if ctx.record_pat_syntax.is_some() {
+        return;
+    }
+
     // FIXME: ideally, we should look at the type we are matching against and
     // suggest variants + auto-imports
     ctx.scope().process_all_names(&mut |name, res| {

crates/ra_ide/src/completion/complete_record.rs

@@ -2,7 +2,7 @@
 use crate::completion::{CompletionContext, Completions};
 
 pub(super) fn complete_record(acc: &mut Completions, ctx: &CompletionContext) -> Option<()> {
-    let missing_fields = match (ctx.record_lit_pat.as_ref(), ctx.record_lit_syntax.as_ref()) {
+    let missing_fields = match (ctx.record_pat_syntax.as_ref(), ctx.record_lit_syntax.as_ref()) {
         (None, None) => return None,
         (Some(_), Some(_)) => unreachable!("A record cannot be both a literal and a pattern"),
         (Some(record_pat), _) => ctx.sema.record_pattern_missing_fields(record_pat),

crates/ra_ide/src/completion/complete_unqualified_path.rs

@@ -3,7 +3,14 @@
 use crate::completion::{CompletionContext, Completions};
 
 pub(super) fn complete_unqualified_path(acc: &mut Completions, ctx: &CompletionContext) {
-    if !(ctx.is_trivial_path && !ctx.is_pat_binding_or_const && !ctx.record_lit_syntax.is_some()) {
+    if !ctx.is_trivial_path {
+        return;
+    }
+
+    if ctx.is_pat_binding_or_const
+        || ctx.record_lit_syntax.is_some()
+        || ctx.record_pat_syntax.is_some()
+    {
         return;
     }
 

crates/ra_ide/src/completion/completion_context.rs

@@ -30,7 +30,7 @@ pub(crate) struct CompletionContext<'a> {
     pub(super) function_syntax: Option<ast::FnDef>,
     pub(super) use_item_syntax: Option<ast::UseItem>,
     pub(super) record_lit_syntax: Option<ast::RecordLit>,
-    pub(super) record_lit_pat: Option<ast::RecordPat>,
+    pub(super) record_pat_syntax: Option<ast::RecordPat>,
     pub(super) impl_def: Option<ast::ImplDef>,
     pub(super) is_param: bool,
     /// If a name-binding or reference to a const in a pattern.
@@ -93,7 +93,7 @@ impl<'a> CompletionContext<'a> {
             function_syntax: None,
             use_item_syntax: None,
             record_lit_syntax: None,
-            record_lit_pat: None,
+            record_pat_syntax: None,
             impl_def: None,
             is_param: false,
             is_pat_binding_or_const: false,
@@ -182,6 +182,11 @@ impl<'a> CompletionContext<'a> {
                 self.is_param = true;
                 return;
             }
+            // FIXME: remove this (V) duplication and make the check more precise
+            if name_ref.syntax().ancestors().find_map(ast::RecordFieldPatList::cast).is_some() {
+                self.record_pat_syntax =
+                    self.sema.find_node_at_offset_with_macros(&original_file, offset);
+            }
             self.classify_name_ref(original_file, name_ref, offset);
         }
 
@@ -211,8 +216,9 @@ impl<'a> CompletionContext<'a> {
                 self.is_param = true;
                 return;
             }
+            // FIXME: remove this (^) duplication and make the check more precise
             if name.syntax().ancestors().find_map(ast::RecordFieldPatList::cast).is_some() {
-                self.record_lit_pat =
+                self.record_pat_syntax =
                     self.sema.find_node_at_offset_with_macros(&original_file, offset);
             }
         }

crates/ra_parser/src/grammar.rs

@@ -282,13 +282,10 @@ fn name_ref(p: &mut Parser) {
 }
 
 fn name_ref_or_index(p: &mut Parser) {
-    if p.at(IDENT) || p.at(INT_NUMBER) {
+    assert!(p.at(IDENT) || p.at(INT_NUMBER));
     let m = p.start();
     p.bump_any();
     m.complete(p, NAME_REF);
-    } else {
-        p.err_and_bump("expected identifier");
-    }
 }
 
 fn error_block(p: &mut Parser, message: &str) {

crates/ra_parser/src/grammar/patterns.rs

@@ -192,16 +192,32 @@ fn record_field_pat_list(p: &mut Parser) {
         match p.current() {
             // A trailing `..` is *not* treated as a DOT_DOT_PAT.
             T![.] if p.at(T![..]) => p.bump(T![..]),
-
-            IDENT | INT_NUMBER if p.nth(1) == T![:] => record_field_pat(p),
             T!['{'] => error_block(p, "expected ident"),
+
+            c => {
+                let m = p.start();
+                match c {
+                    // test record_field_pat
+                    // fn foo() {
+                    //     let S { 0: 1 } = ();
+                    //     let S { x: 1 } = ();
+                    // }
+                    IDENT | INT_NUMBER if p.nth(1) == T![:] => {
+                        name_ref_or_index(p);
+                        p.bump(T![:]);
+                        pattern(p);
+                    }
                     T![box] => {
+                        // FIXME: not all box patterns should be allowed
                         box_pat(p);
                     }
                     _ => {
                         bind_pat(p, false);
                     }
                 }
+                m.complete(p, RECORD_FIELD_PAT);
+            }
+        }
         if !p.at(T!['}']) {
             p.expect(T![,]);
         }
@@ -210,26 +226,6 @@ fn record_field_pat_list(p: &mut Parser) {
     m.complete(p, RECORD_FIELD_PAT_LIST);
 }
 
-// test record_field_pat
-// fn foo() {
-//     let S { 0: 1 } = ();
-//     let S { x: 1 } = ();
-// }
-fn record_field_pat(p: &mut Parser) {
-    assert!(p.at(IDENT) || p.at(INT_NUMBER));
-    assert!(p.nth(1) == T![:]);
-
-    let m = p.start();
-
-    if !p.eat(INT_NUMBER) {
-        name(p)
-    }
-
-    p.bump_any();
-    pattern(p);
-    m.complete(p, RECORD_FIELD_PAT);
-}
-
 // test placeholder_pat
 // fn main() { let _ = (); }
 fn placeholder_pat(p: &mut Parser) -> CompletedMarker {

crates/ra_syntax/src/ast.rs

@@ -18,8 +18,8 @@ use crate::{
 pub use self::{
     expr_extensions::{ArrayExprKind, BinOp, ElseBranch, LiteralKind, PrefixOp, RangeOp},
     extensions::{
-        AttrKind, FieldKind, PathSegmentKind, SelfParamKind, SlicePatComponents, StructKind,
-        TypeBoundKind, VisibilityKind,
+        AttrKind, FieldKind, NameOrNameRef, PathSegmentKind, SelfParamKind, SlicePatComponents,
+        StructKind, TypeBoundKind, VisibilityKind,
     },
     generated::{nodes::*, tokens::*},
     tokens::*,

crates/ra_syntax/src/ast/extensions.rs

@@ -1,6 +1,8 @@
 //! Various extension methods to ast Nodes, which are hard to code-generate.
 //! Extensions for various expressions live in a sibling `expr_extensions` module.
 
+use std::fmt;
+
 use itertools::Itertools;
 use ra_parser::SyntaxKind;
 
@@ -217,6 +219,34 @@ impl ast::RecordField {
     }
 }
 
+pub enum NameOrNameRef {
+    Name(ast::Name),
+    NameRef(ast::NameRef),
+}
+
+impl fmt::Display for NameOrNameRef {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            NameOrNameRef::Name(it) => fmt::Display::fmt(it, f),
+            NameOrNameRef::NameRef(it) => fmt::Display::fmt(it, f),
+        }
+    }
+}
+
+impl ast::RecordFieldPat {
+    /// Deals with field init shorthand
+    pub fn field_name(&self) -> Option<NameOrNameRef> {
+        if let Some(name_ref) = self.name_ref() {
+            return Some(NameOrNameRef::NameRef(name_ref));
+        }
+        if let Some(ast::Pat::BindPat(pat)) = self.pat() {
+            let name = pat.name()?;
+            return Some(NameOrNameRef::Name(name));
+        }
+        None
+    }
+}
+
 impl ast::EnumVariant {
     pub fn parent_enum(&self) -> ast::EnumDef {
         self.syntax()

crates/ra_syntax/src/ast/generated/nodes.rs

@@ -1806,8 +1806,8 @@ impl AstNode for RecordFieldPat {
     fn syntax(&self) -> &SyntaxNode { &self.syntax }
 }
 impl ast::AttrsOwner for RecordFieldPat {}
-impl ast::NameOwner for RecordFieldPat {}
 impl RecordFieldPat {
+    pub fn name_ref(&self) -> Option<NameRef> { support::child(&self.syntax) }
     pub fn colon_token(&self) -> Option<SyntaxToken> { support::token(&self.syntax, T![:]) }
     pub fn pat(&self) -> Option<Pat> { support::child(&self.syntax) }
 }

crates/ra_syntax/test_data/parser/inline/ok/0102_record_field_pat_list.rast

@@ -44,11 +44,13 @@ SOURCE_FILE@[0; 119)
             RECORD_FIELD_PAT_LIST@[40; 56)
               L_CURLY@[40; 41) "{"
               WHITESPACE@[41; 42) " "
+              RECORD_FIELD_PAT@[42; 43)
                 BIND_PAT@[42; 43)
                   NAME@[42; 43)
                     IDENT@[42; 43) "f"
               COMMA@[43; 44) ","
               WHITESPACE@[44; 45) " "
+              RECORD_FIELD_PAT@[45; 54)
                 BIND_PAT@[45; 54)
                   REF_KW@[45; 48) "ref"
                   WHITESPACE@[48; 49) " "
@@ -79,7 +81,7 @@ SOURCE_FILE@[0; 119)
               L_CURLY@[73; 74) "{"
               WHITESPACE@[74; 75) " "
               RECORD_FIELD_PAT@[75; 79)
-                NAME@[75; 76)
+                NAME_REF@[75; 76)
                   IDENT@[75; 76) "h"
                 COLON@[76; 77) ":"
                 WHITESPACE@[77; 78) " "
@@ -110,7 +112,7 @@ SOURCE_FILE@[0; 119)
               L_CURLY@[101; 102) "{"
               WHITESPACE@[102; 103) " "
               RECORD_FIELD_PAT@[103; 107)
-                NAME@[103; 104)
+                NAME_REF@[103; 104)
                   IDENT@[103; 104) "h"
                 COLON@[104; 105) ":"
                 WHITESPACE@[105; 106) " "

crates/ra_syntax/test_data/parser/inline/ok/0143_box_pat.rast

@@ -44,6 +44,7 @@ SOURCE_FILE@[0; 118)
               RECORD_FIELD_PAT_LIST@[50; 81)
                 L_CURLY@[50; 51) "{"
                 WHITESPACE@[51; 52) " "
+                RECORD_FIELD_PAT@[52; 57)
                   BOX_PAT@[52; 57)
                     BOX_KW@[52; 55) "box"
                     WHITESPACE@[55; 56) " "
@@ -53,7 +54,7 @@ SOURCE_FILE@[0; 118)
                 COMMA@[57; 58) ","
                 WHITESPACE@[58; 59) " "
                 RECORD_FIELD_PAT@[59; 79)
-                  NAME@[59; 60)
+                  NAME_REF@[59; 60)
                     IDENT@[59; 60) "j"
                   COLON@[60; 61) ":"
                   WHITESPACE@[61; 62) " "

crates/ra_syntax/test_data/parser/inline/ok/0145_record_field_pat.rast

@@ -25,6 +25,7 @@ SOURCE_FILE@[0; 63)
               L_CURLY@[21; 22) "{"
               WHITESPACE@[22; 23) " "
               RECORD_FIELD_PAT@[23; 27)
+                NAME_REF@[23; 24)
                   INT_NUMBER@[23; 24) "0"
                 COLON@[24; 25) ":"
                 WHITESPACE@[25; 26) " "
@@ -54,7 +55,7 @@ SOURCE_FILE@[0; 63)
               L_CURLY@[46; 47) "{"
               WHITESPACE@[47; 48) " "
               RECORD_FIELD_PAT@[48; 52)
-                NAME@[48; 49)
+                NAME_REF@[48; 49)
                   IDENT@[48; 49) "x"
                 COLON@[49; 50) ":"
                 WHITESPACE@[50; 51) " "

crates/ra_syntax/test_data/parser/ok/0063_trait_fn_patterns.rast

@@ -68,11 +68,13 @@ SOURCE_FILE@[0; 170)
               RECORD_FIELD_PAT_LIST@[59; 67)
                 L_CURLY@[59; 60) "{"
                 WHITESPACE@[60; 61) " "
+                RECORD_FIELD_PAT@[61; 62)
                   BIND_PAT@[61; 62)
                     NAME@[61; 62)
                       IDENT@[61; 62) "a"
                 COMMA@[62; 63) ","
                 WHITESPACE@[63; 64) " "
+                RECORD_FIELD_PAT@[64; 65)
                   BIND_PAT@[64; 65)
                     NAME@[64; 65)
                       IDENT@[64; 65) "b"

crates/ra_syntax/test_data/parser/ok/0064_impl_fn_params.rast

@@ -71,11 +71,13 @@ SOURCE_FILE@[0; 137)
               RECORD_FIELD_PAT_LIST@[58; 66)
                 L_CURLY@[58; 59) "{"
                 WHITESPACE@[59; 60) " "
+                RECORD_FIELD_PAT@[60; 61)
                   BIND_PAT@[60; 61)
                     NAME@[60; 61)
                       IDENT@[60; 61) "a"
                 COMMA@[61; 62) ","
                 WHITESPACE@[62; 63) " "
+                RECORD_FIELD_PAT@[63; 64)
                   BIND_PAT@[63; 64)
                     NAME@[63; 64)
                       IDENT@[63; 64) "b"

xtask/src/ast_src.rs

@@ -511,7 +511,7 @@ pub(crate) const AST_SRC: AstSrc = AstSrc {
             T![..],
             T!['}']
         }
-        struct RecordFieldPat: AttrsOwner, NameOwner { T![:], Pat }
+        struct RecordFieldPat: AttrsOwner { NameRef, T![:], Pat }
 
         struct TupleStructPat { Path, T!['('], args: [Pat], T![')'] }
         struct TuplePat { T!['('], args: [Pat], T![')'] }