1 files changed, 45 insertions, 9 deletions
diff --git a/src/lang/ts-lang/builtin/sbuiltin.ts b/src/lang/ts-lang/builtin/sbuiltin.ts
index f873666..c92fd6a 100644
--- a/src/lang/ts-lang/builtin/sbuiltin.ts
+++ b/src/lang/ts-lang/builtin/sbuiltin.ts
@@ -1,27 +1,63 @@
+import { FnError } from ".";
 import { ASTNode, StackFrame } from "../core/common";
-import { CallFn, FnPrim, GetEvaluatedChildren, EvalError } from "../core/eval";
+import {
+  CallFn,
+  FnPrim,
+  GetEvaluatedChildren,
+  EvalError,
+  _Evaluate,
+} from "../core/eval";
 import { ExtractNumber, ToString } from "../util";
 
 export type SBUILTIN_Call<
   Node extends ASTNode,
-  Frame extends StackFrame
-> = GetEvaluatedChildren<Node, Frame> extends [
+  Frame extends StackFrame,
+  Callstack extends readonly string[]
+> = GetEvaluatedChildren<Node, Frame, Callstack> extends [
   infer Fn,
   ...infer Values extends readonly any[]
 ]
-  ? CallFn<Fn, Values, Frame>
+  ? CallFn<Fn, Values, Frame, Callstack>
   : EvalError<`Invalid params for function call: ${ToString<
-      GetEvaluatedChildren<Node, Frame>
+      GetEvaluatedChildren<Node, Frame, Callstack>
     >}`>;
 
 export type SBUILTIN_Map<
   Node extends ASTNode,
-  Frame extends StackFrame
-> = GetEvaluatedChildren<Node, Frame> extends [
+  Frame extends StackFrame,
+  Callstack extends readonly string[]
+> = GetEvaluatedChildren<Node, Frame, Callstack> extends [
   infer Arr extends readonly any[],
   infer Fn extends FnPrim
 ]
-  ? { [Idx in keyof Arr]: CallFn<Fn, [Arr[Idx], ExtractNumber<Idx>], Frame> }
+  ? {
+      [Idx in keyof Arr]: CallFn<
+        Fn,
+        [Arr[Idx], ExtractNumber<Idx>],
+        Frame,
+        Callstack
+      >;
+    }
   : EvalError<`Invalid params for map: ${ToString<
-      GetEvaluatedChildren<Node, Frame>
+      GetEvaluatedChildren<Node, Frame, Callstack>
     >}`>;
+
+export type SBUILTIN_IfElse<
+  Node extends ASTNode,
+  Frame extends StackFrame,
+  Callstack extends readonly string[]
+> = Node["children"] extends infer Children extends readonly ASTNode[]
+  ? Children extends [infer A, infer B, infer C, infer D]
+    ? FnError<`Invalid args for "if": ${ToString<Children>}`>
+    : Children extends [
+        infer Cond extends ASTNode,
+        infer TrueVal extends ASTNode,
+        infer FalseVal extends ASTNode
+      ]
+    ? _Evaluate<Cond, Frame, Callstack> extends true
+      ? _Evaluate<TrueVal, Frame, Callstack>
+      : _Evaluate<Cond, Frame, Callstack> extends false
+      ? _Evaluate<FalseVal, Frame, Callstack>
+      : FnError<`Condition value ${ToString<Cond>} is not a boolean`>
+    : FnError<`Invalid args for "if": ${ToString<Children>}`>
+  : never;