Make OD-API for consistent for constraints, LHS patterns, RHS actions.

util/eval.py

@@ -1,9 +1,13 @@
 # based on https://stackoverflow.com/a/39381428
 # Parses and executes a block of Python code, and returns the eval result of the last statement
 import ast
-def exec_then_eval(code, _globals, _locals):
+def exec_then_eval(code, _globals={}, _locals={}):
     block = ast.parse(code, mode='exec')
     # assumes last node is an expression
     last = ast.Expression(block.body.pop().value)
-    exec(compile(block, '<string>', mode='exec'), _globals, _locals)
-    return eval(compile(last, '<string>', mode='eval'), _globals, _locals)
+    extended_globals = {
+        '__builtins__': {'isinstance': isinstance, 'print': print, 'int': int, 'float': float, 'bool': bool, 'str': str, 'tuple': tuple, 'len': len, 'set': set, 'dict': dict },
+        **_globals,
+    }
+    exec(compile(block, '<string>', mode='exec'), extended_globals, _locals)
+    return eval(compile(last, '<string>', mode='eval'), extended_globals, _locals)