def test_native(self):
add = NativeFunction(Parser.native_function("add(x, y)"),
lambda x, y: x + y)
mod = Module([Parser.rule("a(x) --> add(x, 1)")], [add])
term = Parser.term("a(1)")
result = Interpreter(mod).interpret(term)
self.assertEqual(result, IntTerm(2))
Parser.rule("E |- retrieve(x) --> E[x]"),
# TODO rename this to something other than ifz... it is not an ifz
Parser.rule(
"ifz(cond, then, else) --> result where cond --> cond2; case cond2 of {0 => result => else otherwise => result => then}"
),
while_rule,
Parser.rule("while2(cond, 0, then) --> 0"),
Parser.rule(
"while2(cond, value, then) --> while(cond, then) where then --> ignored"
)
]
def write(s, unused):
print(s)
return 0
native_functions = [
NativeFunction(Parser.native_function("write(x)"),
write), # TODO rpython demands it
NativeFunction(Parser.native_function("add(x, y)"), lambda x, y: x + y),
NativeFunction(Parser.native_function("sub(x, y)"), lambda x, y: x - y),
NativeFunction(Parser.native_function("mul(x, y)"), lambda x, y: x * y),
NativeFunction(Parser.native_function("div(x, y)"), lambda x, y: x // y),
NativeFunction(Parser.native_function("leq(x, y)"),
lambda x, y: int(x <= y))
]
e2 = Module(rules, native_functions)