Auto merge of #12962 - lowr:patch/parse-last-range-pattern, r=Veykril

Parse range patterns in struct and slice without trailing comma

Resolves #12935

This patch includes the support for range patterns in slices, which is unstable (tracked in https://github.com/rust-lang/rust/issues/67264). If it's not desired I can remove it.

5 files changed, 181 insertions, 7 deletions

diff --git a/crates/parser/src/grammar/patterns.rs b/crates/parser/src/grammar/patterns.rs
index 4cbf1030614..7e21a808da0 100644
--- a/crates/parser/src/grammar/patterns.rs
+++ b/crates/parser/src/grammar/patterns.rs
@@ -75,6 +75,16 @@ fn pattern_single_r(p: &mut Parser<'_>, recovery_set: TokenSet) {
         //         Some(1..) => ()
         //     }
         //
+        //     match () {
+        //         S { a: 0 } => (),
+        //         S { a: 1.. } => (),
+        //     }
+        //
+        //     match () {
+        //         [0] => (),
+        //         [1..] => (),
+        //     }
+        //
         //     match (10 as u8, 5 as u8) {
         //         (0, _) => (),
         //         (1.., _) => ()
@@ -88,11 +98,27 @@ fn pattern_single_r(p: &mut Parser<'_>, recovery_set: TokenSet) {
                 let m = lhs.precede(p);
                 p.bump(range_op);
 
-                // `0 .. =>` or `let 0 .. =` or `Some(0 .. )`
-                //       ^                ^                ^
-                if p.at(T![=]) | p.at(T![')']) | p.at(T![,]) {
+                // testing if we're at one of the following positions:
+                // `0 .. =>`
+                //       ^
+                // `let 0 .. =`
+                //           ^
+                // `let 0..: _ =`
+                //         ^
+                // (1.., _)
+                //     ^
+                // `Some(0 .. )`
+                //            ^
+                // `S { t: 0.. }`
+                //             ^
+                // `[0..]`
+                //      ^
+                if matches!(p.current(), T![=] | T![,] | T![:] | T![')'] | T!['}'] | T![']']) {
                     // test half_open_range_pat
-                    // fn f() { let 0 .. = 1u32; }
+                    // fn f() {
+                    //     let 0 .. = 1u32;
+                    //     let 0..: _ = 1u32;
+                    // }
                 } else {
                     atom_pat(p, recovery_set);
                 }
diff --git a/crates/parser/test_data/parser/inline/ok/0058_range_pat.rast b/crates/parser/test_data/parser/inline/ok/0058_range_pat.rast
index 44c967e8dc5..cfef5d3f953 100644
--- a/crates/parser/test_data/parser/inline/ok/0058_range_pat.rast
+++ b/crates/parser/test_data/parser/inline/ok/0058_range_pat.rast
@@ -172,6 +172,122 @@ SOURCE_FILE
               WHITESPACE "\n    "
               R_CURLY "}"
         WHITESPACE "\n\n    "
+        EXPR_STMT
+          MATCH_EXPR
+            MATCH_KW "match"
+            WHITESPACE " "
+            TUPLE_EXPR
+              L_PAREN "("
+              R_PAREN ")"
+            WHITESPACE " "
+            MATCH_ARM_LIST
+              L_CURLY "{"
+              WHITESPACE "\n        "
+              MATCH_ARM
+                RECORD_PAT
+                  PATH
+                    PATH_SEGMENT
+                      NAME_REF
+                        IDENT "S"
+                  WHITESPACE " "
+                  RECORD_PAT_FIELD_LIST
+                    L_CURLY "{"
+                    WHITESPACE " "
+                    RECORD_PAT_FIELD
+                      NAME_REF
+                        IDENT "a"
+                      COLON ":"
+                      WHITESPACE " "
+                      LITERAL_PAT
+                        LITERAL
+                          INT_NUMBER "0"
+                    WHITESPACE " "
+                    R_CURLY "}"
+                WHITESPACE " "
+                FAT_ARROW "=>"
+                WHITESPACE " "
+                TUPLE_EXPR
+                  L_PAREN "("
+                  R_PAREN ")"
+                COMMA ","
+              WHITESPACE "\n        "
+              MATCH_ARM
+                RECORD_PAT
+                  PATH
+                    PATH_SEGMENT
+                      NAME_REF
+                        IDENT "S"
+                  WHITESPACE " "
+                  RECORD_PAT_FIELD_LIST
+                    L_CURLY "{"
+                    WHITESPACE " "
+                    RECORD_PAT_FIELD
+                      NAME_REF
+                        IDENT "a"
+                      COLON ":"
+                      WHITESPACE " "
+                      RANGE_PAT
+                        LITERAL_PAT
+                          LITERAL
+                            INT_NUMBER "1"
+                        DOT2 ".."
+                    WHITESPACE " "
+                    R_CURLY "}"
+                WHITESPACE " "
+                FAT_ARROW "=>"
+                WHITESPACE " "
+                TUPLE_EXPR
+                  L_PAREN "("
+                  R_PAREN ")"
+                COMMA ","
+              WHITESPACE "\n    "
+              R_CURLY "}"
+        WHITESPACE "\n\n    "
+        EXPR_STMT
+          MATCH_EXPR
+            MATCH_KW "match"
+            WHITESPACE " "
+            TUPLE_EXPR
+              L_PAREN "("
+              R_PAREN ")"
+            WHITESPACE " "
+            MATCH_ARM_LIST
+              L_CURLY "{"
+              WHITESPACE "\n        "
+              MATCH_ARM
+                SLICE_PAT
+                  L_BRACK "["
+                  LITERAL_PAT
+                    LITERAL
+                      INT_NUMBER "0"
+                  R_BRACK "]"
+                WHITESPACE " "
+                FAT_ARROW "=>"
+                WHITESPACE " "
+                TUPLE_EXPR
+                  L_PAREN "("
+                  R_PAREN ")"
+                COMMA ","
+              WHITESPACE "\n        "
+              MATCH_ARM
+                SLICE_PAT
+                  L_BRACK "["
+                  RANGE_PAT
+                    LITERAL_PAT
+                      LITERAL
+                        INT_NUMBER "1"
+                    DOT2 ".."
+                  R_BRACK "]"
+                WHITESPACE " "
+                FAT_ARROW "=>"
+                WHITESPACE " "
+                TUPLE_EXPR
+                  L_PAREN "("
+                  R_PAREN ")"
+                COMMA ","
+              WHITESPACE "\n    "
+              R_CURLY "}"
+        WHITESPACE "\n\n    "
         MATCH_EXPR
           MATCH_KW "match"
           WHITESPACE " "
diff --git a/crates/parser/test_data/parser/inline/ok/0058_range_pat.rs b/crates/parser/test_data/parser/inline/ok/0058_range_pat.rs
index 6c586a89560..2411d51096b 100644
--- a/crates/parser/test_data/parser/inline/ok/0058_range_pat.rs
+++ b/crates/parser/test_data/parser/inline/ok/0058_range_pat.rs
@@ -11,6 +11,16 @@ fn main() {
         Some(1..) => ()
     }
 
+    match () {
+        S { a: 0 } => (),
+        S { a: 1.. } => (),
+    }
+
+    match () {
+        [0] => (),
+        [1..] => (),
+    }
+
     match (10 as u8, 5 as u8) {
         (0, _) => (),
         (1.., _) => ()
diff --git a/crates/parser/test_data/parser/inline/ok/0166_half_open_range_pat.rast b/crates/parser/test_data/parser/inline/ok/0166_half_open_range_pat.rast
index 3d3587a7063..4b401b60df0 100644
--- a/crates/parser/test_data/parser/inline/ok/0166_half_open_range_pat.rast
+++ b/crates/parser/test_data/parser/inline/ok/0166_half_open_range_pat.rast
@@ -11,7 +11,7 @@ SOURCE_FILE
     BLOCK_EXPR
       STMT_LIST
         L_CURLY "{"
-        WHITESPACE " "
+        WHITESPACE "\n    "
         LET_STMT
           LET_KW "let"
           WHITESPACE " "
@@ -27,6 +27,25 @@ SOURCE_FILE
           LITERAL
             INT_NUMBER "1u32"
           SEMICOLON ";"
-        WHITESPACE " "
+        WHITESPACE "\n    "
+        LET_STMT
+          LET_KW "let"
+          WHITESPACE " "
+          RANGE_PAT
+            LITERAL_PAT
+              LITERAL
+                INT_NUMBER "0"
+            DOT2 ".."
+          COLON ":"
+          WHITESPACE " "
+          INFER_TYPE
+            UNDERSCORE "_"
+          WHITESPACE " "
+          EQ "="
+          WHITESPACE " "
+          LITERAL
+            INT_NUMBER "1u32"
+          SEMICOLON ";"
+        WHITESPACE "\n"
         R_CURLY "}"
   WHITESPACE "\n"
diff --git a/crates/parser/test_data/parser/inline/ok/0166_half_open_range_pat.rs b/crates/parser/test_data/parser/inline/ok/0166_half_open_range_pat.rs
index 1360eda0565..c9386a221a9 100644
--- a/crates/parser/test_data/parser/inline/ok/0166_half_open_range_pat.rs
+++ b/crates/parser/test_data/parser/inline/ok/0166_half_open_range_pat.rs
@@ -1 +1,4 @@
-fn f() { let 0 .. = 1u32; }
+fn f() {
+    let 0 .. = 1u32;
+    let 0..: _ = 1u32;
+}