ast: add IfStmt and IfBranch

src/ast.zig

@@ -20,8 +20,6 @@ pub const NodeType = enum {
 
 pub const ParamDecl = struct {
     name: Token,
-
-    // TODO types
     typ: Token,
 };
 
@@ -81,26 +79,28 @@ pub const VarDecl = struct {
 pub const Expr = union(ExprType) {
     Assign: AssignExpr,
     VarDecl: VarDecl,
+
     Binary: BinaryExpr,
     Unary: UnaryExpr,
     Literal: LiteralExpr,
+
     Variable: Token,
     Grouping: *Expr,
 };
 
-// TODO
-//pub const IfStmt = struct {
-//    condition: *Expr,
-//    then_branch: *StmtList,
-//    else_branch: *StmtList,
-//};
+pub const IfBranch = std.ArrayList(Stmt);
+
+pub const IfStmt = struct {
+    condition: *Expr,
+    then_branch: IfBranch,
+    else_branch: IfBranch,
+};
 
 pub const Stmt = union(enum) {
     Expr: *Expr,
     Println: *Expr,
 
-    // TODO
-    //If: IfStmt,
+    If: IfStmt,
 
     pub fn mkPrintln(allocator: *std.mem.Allocator, expr: *Expr) !*Stmt {
         var println = try allocator.create(Stmt);