Support if-let in scopes

2 files changed, 72 insertions, 6 deletions

diff --git a/crates/libsyntax2/src/ast/generated.rs b/crates/libsyntax2/src/ast/generated.rs
index 1dd161f52..6891e857c 100644
--- a/crates/libsyntax2/src/ast/generated.rs
+++ b/crates/libsyntax2/src/ast/generated.rs
@@ -141,7 +141,11 @@ impl<'a> AstNode<'a> for BlockExpr<'a> {
     fn syntax(self) -> SyntaxNodeRef<'a> { self.syntax }
 }
 
-impl<'a> BlockExpr<'a> {}
+impl<'a> BlockExpr<'a> {
+    pub fn block(self) -> Option<Block<'a>> {
+        super::child_opt(self)
+    }
+}
 
 // BreakExpr
 #[derive(Debug, Clone, Copy)]
@@ -197,6 +201,32 @@ impl<'a> AstNode<'a> for CastExpr<'a> {
 
 impl<'a> CastExpr<'a> {}
 
+// Condition
+#[derive(Debug, Clone, Copy)]
+pub struct Condition<'a> {
+    syntax: SyntaxNodeRef<'a>,
+}
+
+impl<'a> AstNode<'a> for Condition<'a> {
+    fn cast(syntax: SyntaxNodeRef<'a>) -> Option<Self> {
+        match syntax.kind() {
+            CONDITION => Some(Condition { syntax }),
+            _ => None,
+        }
+    }
+    fn syntax(self) -> SyntaxNodeRef<'a> { self.syntax }
+}
+
+impl<'a> Condition<'a> {
+    pub fn pat(self) -> Option<Pat<'a>> {
+        super::child_opt(self)
+    }
+
+    pub fn expr(self) -> Option<Expr<'a>> {
+        super::child_opt(self)
+    }
+}
+
 // ConstDef
 #[derive(Debug, Clone, Copy)]
 pub struct ConstDef<'a> {
@@ -403,7 +433,11 @@ impl<'a> AstNode<'a> for ExprStmt<'a> {
     fn syntax(self) -> SyntaxNodeRef<'a> { self.syntax }
 }
 
-impl<'a> ExprStmt<'a> {}
+impl<'a> ExprStmt<'a> {
+    pub fn expr(self) -> Option<Expr<'a>> {
+        super::child_opt(self)
+    }
+}
 
 // FieldExpr
 #[derive(Debug, Clone, Copy)]
@@ -504,7 +538,11 @@ impl<'a> AstNode<'a> for ForExpr<'a> {
     fn syntax(self) -> SyntaxNodeRef<'a> { self.syntax }
 }
 
-impl<'a> ForExpr<'a> {}
+impl<'a> ForExpr<'a> {
+    pub fn body(self) -> Option<Block<'a>> {
+        super::child_opt(self)
+    }
+}
 
 // ForType
 #[derive(Debug, Clone, Copy)]
@@ -540,7 +578,11 @@ impl<'a> AstNode<'a> for IfExpr<'a> {
     fn syntax(self) -> SyntaxNodeRef<'a> { self.syntax }
 }
 
-impl<'a> IfExpr<'a> {}
+impl<'a> IfExpr<'a> {
+    pub fn condition(self) -> Option<Condition<'a>> {
+        super::child_opt(self)
+    }
+}
 
 // ImplItem
 #[derive(Debug, Clone, Copy)]
@@ -674,7 +716,11 @@ impl<'a> AstNode<'a> for LoopExpr<'a> {
     fn syntax(self) -> SyntaxNodeRef<'a> { self.syntax }
 }
 
-impl<'a> LoopExpr<'a> {}
+impl<'a> LoopExpr<'a> {
+    pub fn body(self) -> Option<Block<'a>> {
+        super::child_opt(self)
+    }
+}
 
 // MatchArm
 #[derive(Debug, Clone, Copy)]
@@ -1742,5 +1788,13 @@ impl<'a> AstNode<'a> for WhileExpr<'a> {
     fn syntax(self) -> SyntaxNodeRef<'a> { self.syntax }
 }
 
-impl<'a> WhileExpr<'a> {}
+impl<'a> WhileExpr<'a> {
+    pub fn condition(self) -> Option<Condition<'a>> {
+        super::child_opt(self)
+    }
+
+    pub fn body(self) -> Option<Block<'a>> {
+        super::child_opt(self)
+    }
+}
 
diff --git a/crates/libsyntax2/src/ast/mod.rs b/crates/libsyntax2/src/ast/mod.rs
index 6217c5b74..2ebee6a4f 100644
--- a/crates/libsyntax2/src/ast/mod.rs
+++ b/crates/libsyntax2/src/ast/mod.rs
@@ -115,6 +115,18 @@ impl<'a> Module<'a> {
     }
 }
 
+impl<'a> IfExpr<'a> {
+    pub fn then_branch(self) -> Option<Block<'a>> {
+        self.blocks().nth(0)
+    }
+    pub fn else_branch(self) -> Option<Block<'a>> {
+        self.blocks().nth(1)
+    }
+    fn blocks(self) -> impl Iterator<Item=Block<'a>> {
+        children(self)
+    }
+}
+
 fn child_opt<'a, P: AstNode<'a>, C: AstNode<'a>>(parent: P) -> Option<C> {
     children(parent).next()
 }