Draft: Resolve "Short circuiting and lazy evaluation"

Closes #49

src/virtmat/language/interpreter/deferred_executor.py

@@ -60,17 +60,17 @@ def dummies_right(func, args):
 
 def log_eval(func):
     """a logger indicating when a func property is eventually evaluated"""
-    def decorator(obj):
-        func_ret, pars = func(obj)
+    def logged_func(obj):
+        ret_func, pars = func(obj)
         logger = get_logger(__name__)
         obj_repr = repr(obj)
 
-        def newfunc_ret(*args, **kwargs):
-            ret = func_ret(*args, **kwargs)
-            logger.debug(' evaluated %s: %s', obj_repr, ret)
-            return ret
-        return newfunc_ret, pars
-    return decorator
+        def new_ret_func(*args, **kwargs):
+            ret_val = ret_func(*args, **kwargs)
+            logger.debug(' evaluated %s: %s', obj_repr, ret_val)
+            return ret_val
+        return new_ret_func, pars
+    return logged_func
 
 
 def print_func(self):
@@ -120,7 +120,7 @@ def type_func(self):
            'datatype': get_datatype_name(datatype)}
     if (isinstance_m(par, ['GeneralReference']) and isinstance_m(par.ref, ['ObjectImport'])
        and callable(get_object_import(par.ref)) or not numeric):
-        return (lambda: typemap['Table']([dct]), tuple())
+        return lambda: typemap['Table']([dct]), tuple()
     assert numeric
 
     def retfunc(val):
@@ -620,7 +620,7 @@ def func_reduce_func(self, func):
     def get_func_reduce_val(*args):
         iargs = iter(args)
         fargs = [list(islice(iargs, pl)) for pl in pars_lens]
-        return func([f(*a) for f, a in zip(funcs, fargs)])
+        return func(f(*a) for f, a in zip(funcs, fargs))
     return get_func_reduce_val, tuple(chain.from_iterable(pars))
 
 
@@ -643,7 +643,7 @@ def in_func(self):
         iargs = iter(args)
         eargs = list(islice(iargs, elem_pars_len))
         pargs = [list(islice(iargs, pl)) for pl in pars_lens]
-        return elem_func(*eargs) in [f(*a) for f, a in zip(funcs, pargs)]
+        return elem_func(*eargs) in (f(*a) for f, a in zip(funcs, pargs))
     return get_in_val, tuple(chain.from_iterable(elem_pars+pars))
 
 
@@ -706,6 +706,44 @@ def binary_operation_func(self, operator):
     return binop_func(func, ops)
 
 
+def or_func(self):
+    """return a 2-tuple containing a function and a list of parameters"""
+    funcs = [op.func[0] for op in self.operands]
+    pars = [op.func[1] for op in self.operands]
+    plens = [len(p) for p in pars]
+
+    def get_or_val(*args):
+        null = False
+        iter_args = iter(args)
+        for func, plen in zip(funcs, plens):
+            op_val = func(*list(islice(iter_args, plen)))
+            if op_val:
+                return True
+            if op_val is None:
+                null = True
+        return False if not null else None
+    return get_or_val, tuple(chain.from_iterable(pars))
+
+
+def and_func(self):
+    """return a 2-tuple containing a function and a list of parameters"""
+    funcs = [op.func[0] for op in self.operands]
+    pars = [op.func[1] for op in self.operands]
+    plens = [len(p) for p in pars]
+
+    def get_and_val(*args):
+        null = False
+        iter_args = iter(args)
+        for func, plen in zip(funcs, plens):
+            op_val = func(*list(islice(iter_args, plen)))
+            if op_val is None:
+                null = True
+            elif not op_val:
+                return False
+        return True if not null else None
+    return get_and_val, tuple(chain.from_iterable(pars))
+
+
 def not_func(self, operator):
     """return a 2-tuple containing a function and a list of parameters"""
     if self.not_:
@@ -954,8 +992,8 @@ def add_func_properties(metamodel):
         'Expression': expression_func,
         'Operand': operand_func,
         'BooleanOperand': operand_func,
-        'And': partial(binary_operation_func, operator='and'),
-        'Or': partial(binary_operation_func, operator='or'),
+        'And': and_func,
+        'Or': or_func,
         'Not': partial(not_func, operator=not_),
         'Comparison': comparison_func,
         'Real': real_func,