new file

Author: jsiek

type_check_Pif.py

@@ -0,0 +1,65 @@
+from ast import *
+from type_check_Pvar import TypeCheckPvar, check_type_equal
+from utils import *
+
+class TypeCheckPif(TypeCheckPvar):
+          
+  def type_check_exp(self, e, env):
+    match e:
+      case Constant(value) if isinstance(value, bool):
+        return bool
+      case IfExp(test, body, orelse):
+        test_t = self.type_check_exp(test, env)
+        check_type_equal(bool, test_t, test)
+        body_t = self.type_check_exp(body, env)
+        orelse_t = self.type_check_exp(orelse, env)
+        check_type_equal(body_t, orelse_t, e)
+        return body_t
+      case BinOp(left, Sub(), right):
+        l = self.type_check_exp(left, env)
+        check_type_equal(l, int, left)
+        r = self.type_check_exp(right, env)
+        check_type_equal(r, int, right)
+        return int
+      case UnaryOp(Not(), v):
+        t = self.type_check_exp(v, env)
+        check_type_equal(t, bool, v)
+        return bool 
+      case BoolOp(op, values):
+        left = values[0]; right = values[1]
+        l = self.type_check_exp(left, env)
+        check_type_equal(l, bool, left)
+        r = self.type_check_exp(right, env)
+        check_type_equal(r, bool, right)
+        return bool
+      case Compare(left, [cmp], [right]) if isinstance(cmp, Eq) or isinstance(cmp, NotEq):
+        l = self.type_check_exp(left, env)
+        r = self.type_check_exp(right, env)
+        check_type_equal(l, r, e)
+        return bool
+      case Compare(left, [cmp], [right]):
+        l = self.type_check_exp(left, env)
+        check_type_equal(l, int, left)
+        r = self.type_check_exp(right, env)
+        check_type_equal(r, int, right)
+        return bool
+      case Let(Name(x), rhs, body):
+        t = self.type_check_exp(rhs, env)
+        new_env = dict(env); new_env[x] = t
+        return self.type_check_exp(body, new_env)
+      case _:
+        return super().type_check_exp(e, env)
+
+  def type_check_stmts(self, ss, env):
+    if len(ss) == 0:
+      return
+    match ss[0]:
+      case If(test, body, orelse):
+        test_t = self.type_check_exp(test, env)
+        check_type_equal(bool, test_t, test)
+        body_t = self.type_check_stmts(body, env)
+        orelse_t = self.type_check_stmts(orelse, env)
+        check_type_equal(body_t, orelse_t, ss[0])
+        return self.type_check_stmts(ss[1:], env)
+      case _:
+        return super().type_check_stmts(ss, env)