interp and type check for Lwhile

Author: jsiek

interp_Pwhile.py

@@ -0,0 +1,17 @@
+from ast import *
+from interp_Pif import InterpPif
+from utils import *
+
+class InterpPwhile(InterpPif):
+
+  def interp_stmts(self, ss, env):
+    if len(ss) == 0:
+      return
+    match ss[0]:
+      case While(test, body, []):
+        while self.interp_exp(test, env):
+            self.interp_stmts(body, env)
+        return self.interp_stmts(ss[1:], env)
+      case _:
+        return super().interp_stmts(ss, env)
+    

type_check_Pwhile.py

@@ -0,0 +1,19 @@
+from ast import *
+from type_check_Pvar import check_type_equal
+from type_check_Pif import TypeCheckPif
+from utils import *
+
+class TypeCheckPwhile(TypeCheckPif):
+
+  def type_check_stmts(self, ss, env):
+    if len(ss) == 0:
+      return
+    match ss[0]:
+      case While(test, body, []):
+        test_t = self.type_check_exp(test, env)
+        check_type_equal(bool, test_t, test)
+        body_t = self.type_check_stmts(body, env)
+        return self.type_check_stmts(ss[1:], env)
+      case _:
+        return super().type_check_stmts(ss, env)
+