def test_curried_fn_call():
parsed_call = parse("pair 3 true")
pair = Ident("pair")
three = Const(3, Int)
true = Const(True, Bool)
built_call = Call(Call(pair, three), true)
assert parsed_call == built_call
def test_fun_decl_in_let():
fun_decl = parse("""
let
fun f x y z = 1
in
f
end
""")
nested_lambda = parse("""
let
val f = fn x => fn y => fn z => 1
in
f
end
""")
assert fun_decl == nested_lambda
def test_if_stmt():
parsed_if = parse("if true then succ 3 else pred 5")
three = Const(3, Int)
five = Const(5, Int)
true = Const(True, Bool)
pred = Ident("pred")
pred_call = Call(pred, five)
succ = Ident("succ")
succ_call = Call(succ, three)
built_if = If(true, succ_call, pred_call)
assert parsed_if == built_if
def repl():
checker = check.Checker()
while True:
inp = input("==> ")
try:
ast = parse.parse(inp)
except rply.errors.LexingError as err:
idx = err.source_pos.idx
lineno = err.source_pos.lineno
colno = err.source_pos.colno
if lineno < 0 and colno < 0:
pos = f"at index {idx}"
else:
pos = f"on line {lineno}, column {colno} "
print(f"Lexing Error: Unexpected character {pos}!")
continue
except rply.errors.ParsingError as err:
lineno = err.source_pos.lineno
colno = err.source_pos.colno
print(
f"Parsing Error: Unexpected token on line {lineno}, column {colno}!"
)
continue
try:
t = ast.infer_type(checker)
t = checker.unifiers.concretize(t)
print(f"_ : {t}")
except env.EnvKeyError as err:
print(f"Semantic Error: Unrecognized symbol '{err.key}'!")
continue
except unifier_set.UnificationError as err:
print(err.msg)
continue
def test_complex_let():
parsed_let = parse("""
let
val f = fn a => a
in
pair (f 3) (f true)
end
""")
f = Ident("f")
a = Ident("a")
three = Const(3, Int)
true = Const(True, Bool)
pair = Ident("pair")
fn = Lambda(a, a)
f_of_3 = Call(f, three)
f_of_true = Call(f, true)
pair_call = Call(Call(pair, f_of_3), f_of_true)
built_let = Let(f, fn, pair_call)
assert parsed_let == built_let
def test_lambda():
parsed_fn = parse("fn x => zero x")
built_fn = Lambda(Ident("x"), Call(Ident("zero"), Ident("x")))
assert parsed_fn == built_fn