7 files changed, 141 insertions, 7 deletions

diff --git a/src/grammar.ron b/src/grammar.ron
index 8ce5ebc49..9f80b3ebf 100644
--- a/src/grammar.ron
+++ b/src/grammar.ron
@@ -135,6 +135,7 @@ Grammar(
         "PATH_EXPR",
         "LAMBDA_EXPR",
         "IF_EXPR",
+        "WHILE_EXPR",
         "BLOCK_EXPR",
         "RETURN_EXPR",
         "MATCH_EXPR",
diff --git a/src/grammar/expressions/atom.rs b/src/grammar/expressions/atom.rs
index ad654df9e..6a0d47d82 100644
--- a/src/grammar/expressions/atom.rs
+++ b/src/grammar/expressions/atom.rs
@@ -29,7 +29,7 @@ pub(crate) fn literal(p: &mut Parser) -> Option<CompletedMarker> {
 pub(super) const ATOM_EXPR_FIRST: TokenSet =
     token_set_union![
         LITERAL_FIRST,
-        token_set![L_PAREN, PIPE, MOVE_KW, IF_KW, MATCH_KW, UNSAFE_KW, L_CURLY, RETURN_KW,
+        token_set![L_PAREN, PIPE, MOVE_KW, IF_KW, WHILE_KW, MATCH_KW, UNSAFE_KW, L_CURLY, RETURN_KW,
                    IDENT, SELF_KW, SUPER_KW, COLONCOLON ],
     ];
 
@@ -47,6 +47,7 @@ pub(super) fn atom_expr(p: &mut Parser, r: Restrictions) -> Option<CompletedMark
         PIPE => lambda_expr(p),
         MOVE_KW if la == PIPE => lambda_expr(p),
         IF_KW => if_expr(p),
+        WHILE_KW => while_expr(p),
         MATCH_KW => match_expr(p),
         UNSAFE_KW if la == L_CURLY => block_expr(p),
         L_CURLY => block_expr(p),
@@ -97,7 +98,8 @@ fn lambda_expr(p: &mut Parser) -> CompletedMarker {
 fn if_expr(p: &mut Parser) -> CompletedMarker {
     assert!(p.at(IF_KW));
     let m = p.start();
-    if_head(p);
+    p.bump();
+    cond(p);
     block(p);
     if p.at(ELSE_KW) {
         p.bump();
@@ -110,10 +112,28 @@ fn if_expr(p: &mut Parser) -> CompletedMarker {
     m.complete(p, IF_EXPR)
 }
 
-fn if_head(p: &mut Parser) {
-    assert!(p.at(IF_KW));
+// test while_expr
+// fn foo() {
+//     while true {};
+//     while let Some(x) = it.next() {};
+// }
+fn while_expr(p: &mut Parser) -> CompletedMarker {
+    assert!(p.at(WHILE_KW));
+    let m = p.start();
     p.bump();
-    expr_no_struct(p);
+    cond(p);
+    block(p);
+    m.complete(p, WHILE_EXPR)
+}
+
+// test cond
+// fn foo() { if let Some(_) = None {} }
+fn cond(p: &mut Parser) {
+    if p.eat(LET_KW) {
+        patterns::pattern(p);
+        p.expect(EQ);
+    }
+    expr_no_struct(p)
 }
 
 // test match_expr
@@ -152,8 +172,8 @@ fn match_arm(p: &mut Parser) {
             break;
         }
     }
-    if p.at(IF_KW) {
-        if_head(p)
+    if p.eat(IF_KW) {
+        expr_no_struct(p);
     }
     p.expect(FAT_ARROW);
     expr(p);
diff --git a/src/syntax_kinds/generated.rs b/src/syntax_kinds/generated.rs
index 7bdd0267c..1d3d3b9c1 100644
--- a/src/syntax_kinds/generated.rs
+++ b/src/syntax_kinds/generated.rs
@@ -125,6 +125,7 @@ pub enum SyntaxKind {
     PATH_EXPR,
     LAMBDA_EXPR,
     IF_EXPR,
+    WHILE_EXPR,
     BLOCK_EXPR,
     RETURN_EXPR,
     MATCH_EXPR,
@@ -343,6 +344,7 @@ impl SyntaxKind {
             PATH_EXPR => &SyntaxInfo { name: "PATH_EXPR" },
             LAMBDA_EXPR => &SyntaxInfo { name: "LAMBDA_EXPR" },
             IF_EXPR => &SyntaxInfo { name: "IF_EXPR" },
+            WHILE_EXPR => &SyntaxInfo { name: "WHILE_EXPR" },
             BLOCK_EXPR => &SyntaxInfo { name: "BLOCK_EXPR" },
             RETURN_EXPR => &SyntaxInfo { name: "RETURN_EXPR" },
             MATCH_EXPR => &SyntaxInfo { name: "MATCH_EXPR" },
diff --git a/tests/data/parser/inline/0076_cond.rs b/tests/data/parser/inline/0076_cond.rs
new file mode 100644
index 000000000..fdb37ee6f
--- /dev/null
+++ b/tests/data/parser/inline/0076_cond.rs
@@ -0,0 +1 @@
+fn foo() { if let Some(_) = None {} }
diff --git a/tests/data/parser/inline/0076_cond.txt b/tests/data/parser/inline/0076_cond.txt
new file mode 100644
index 000000000..22eed8458
--- /dev/null
+++ b/tests/data/parser/inline/0076_cond.txt
@@ -0,0 +1,42 @@
+FILE@[0; 38)
+  FN_ITEM@[0; 38)
+    FN_KW@[0; 2)
+    NAME@[2; 6)
+      WHITESPACE@[2; 3)
+      IDENT@[3; 6) "foo"
+    PARAM_LIST@[6; 9)
+      L_PAREN@[6; 7)
+      R_PAREN@[7; 8)
+      WHITESPACE@[8; 9)
+    BLOCK_EXPR@[9; 38)
+      L_CURLY@[9; 10)
+      IF_EXPR@[10; 36)
+        WHITESPACE@[10; 11)
+        IF_KW@[11; 13)
+        WHITESPACE@[13; 14)
+        LET_KW@[14; 17)
+        TUPLE_PAT@[17; 26)
+          PATH@[17; 22)
+            PATH_SEGMENT@[17; 22)
+              NAME_REF@[17; 22)
+                WHITESPACE@[17; 18)
+                IDENT@[18; 22) "Some"
+          L_PAREN@[22; 23)
+          PLACEHOLDER_PAT@[23; 24)
+            UNDERSCORE@[23; 24)
+          R_PAREN@[24; 25)
+          WHITESPACE@[25; 26)
+        EQ@[26; 27)
+        PATH_EXPR@[27; 33)
+          PATH@[27; 33)
+            PATH_SEGMENT@[27; 33)
+              NAME_REF@[27; 33)
+                WHITESPACE@[27; 28)
+                IDENT@[28; 32) "None"
+                WHITESPACE@[32; 33)
+        BLOCK_EXPR@[33; 36)
+          L_CURLY@[33; 34)
+          R_CURLY@[34; 35)
+          WHITESPACE@[35; 36)
+      R_CURLY@[36; 37)
+      WHITESPACE@[37; 38)
diff --git a/tests/data/parser/inline/0077_while_expr.rs b/tests/data/parser/inline/0077_while_expr.rs
new file mode 100644
index 000000000..293046a04
--- /dev/null
+++ b/tests/data/parser/inline/0077_while_expr.rs
@@ -0,0 +1,4 @@
+fn foo() {
+    while true {};
+    while let Some(x) = it.next() {};
+}
diff --git a/tests/data/parser/inline/0077_while_expr.txt b/tests/data/parser/inline/0077_while_expr.txt
new file mode 100644
index 000000000..447b4b880
--- /dev/null
+++ b/tests/data/parser/inline/0077_while_expr.txt
@@ -0,0 +1,64 @@
+FILE@[0; 70)
+  FN_ITEM@[0; 70)
+    FN_KW@[0; 2)
+    NAME@[2; 6)
+      WHITESPACE@[2; 3)
+      IDENT@[3; 6) "foo"
+    PARAM_LIST@[6; 9)
+      L_PAREN@[6; 7)
+      R_PAREN@[7; 8)
+      WHITESPACE@[8; 9)
+    BLOCK_EXPR@[9; 70)
+      L_CURLY@[9; 10)
+      EXPR_STMT@[10; 34)
+        WHILE_EXPR@[10; 28)
+          WHITESPACE@[10; 15)
+          WHILE_KW@[15; 20)
+          LITERAL@[20; 26)
+            WHITESPACE@[20; 21)
+            TRUE_KW@[21; 25)
+            WHITESPACE@[25; 26)
+          BLOCK_EXPR@[26; 28)
+            L_CURLY@[26; 27)
+            R_CURLY@[27; 28)
+        SEMI@[28; 29)
+        WHITESPACE@[29; 34)
+      EXPR_STMT@[34; 68)
+        WHILE_EXPR@[34; 66)
+          WHILE_KW@[34; 39)
+          WHITESPACE@[39; 40)
+          LET_KW@[40; 43)
+          TUPLE_PAT@[43; 52)
+            PATH@[43; 48)
+              PATH_SEGMENT@[43; 48)
+                NAME_REF@[43; 48)
+                  WHITESPACE@[43; 44)
+                  IDENT@[44; 48) "Some"
+            L_PAREN@[48; 49)
+            BIND_PAT@[49; 50)
+              NAME@[49; 50)
+                IDENT@[49; 50) "x"
+            R_PAREN@[50; 51)
+            WHITESPACE@[51; 52)
+          EQ@[52; 53)
+          METHOD_CALL_EXPR@[53; 64)
+            PATH_EXPR@[53; 56)
+              PATH@[53; 56)
+                PATH_SEGMENT@[53; 56)
+                  NAME_REF@[53; 56)
+                    WHITESPACE@[53; 54)
+                    IDENT@[54; 56) "it"
+            DOT@[56; 57)
+            NAME_REF@[57; 61)
+              IDENT@[57; 61) "next"
+            ARG_LIST@[61; 64)
+              L_PAREN@[61; 62)
+              R_PAREN@[62; 63)
+              WHITESPACE@[63; 64)
+          BLOCK_EXPR@[64; 66)
+            L_CURLY@[64; 65)
+            R_CURLY@[65; 66)
+        SEMI@[66; 67)
+        WHITESPACE@[67; 68)
+      R_CURLY@[68; 69)
+      WHITESPACE@[69; 70)