Fix #265

compiler/erg_compiler/lib/std/_erg_control.py

@@ -0,0 +1,21 @@
+def if__(cond, then, else_=lambda: None):
+    if cond:
+        return then()
+    else:
+        return else_()
+
+def for__(iterable, body):
+    for i in iterable:
+        body(i)
+
+def while__(cond_block, body):
+    while cond_block():
+        body()
+
+def with__(obj, body):
+    obj.__enter__()
+    body(e)
+    obj.__exit__()
+
+def discard__(obj):
+    pass