def exec(self, code):
"""
Execute the string ``code`` on the interpreter,
returning the result of the last evaluation.
"""
r = NIL
for expr in parse(lex(code)):
r = self.eval(expr)
return r
def test_many_quotes(quotes):
parser = parse(iter([q] * quotes + [lp, rp]))
r = next(parser)
for _ in range(quotes):
assert isinstance(r, Quoted)
r = r.elem
assert r is NIL
with pytest.raises(StopIteration):
next(parser)
def test_many_quote_nested(quotes, inner):
parser = parse(iter([q] * quotes + [lp, inner, rp]))
r = next(parser)
for _ in range(quotes):
assert isinstance(r, Quoted)
r = r.elem
assert r == SExpression(inner)
with pytest.raises(StopIteration):
next(parser)
def parse_string(code: String):
"""
``code`` is a ``String`` containing a single thing once parsed, such as an
s-expression, or a symbol. Simply just lex it, parse it and return it!
Woo-hoo!
>>> from slyther.types import *
>>> parse_string(String("(print x)"))
(list print x)
Note that the ``BuiltinFunction`` decorator takes care of downgrading an
``SExpression`` to a ``ConsList`` for you.
"""
return next(parse(lex(code)))
def test_bad_quotation_rp():
parser = parse(iter([q, s('a'), lp, q, q, q, rp]))
assert next(parser) == Quoted(s('a'))
with pytest.raises(SyntaxError):
next(parser)
def test_bad_quotation_end():
parser = parse(iter([q, -15, q, q]))
assert next(parser) == Quoted(-15)
with pytest.raises(SyntaxError):
next(parser)
def test_missing_lp():
parser = parse(iter([10, rp]))
assert next(parser) is 10
with pytest.raises(SyntaxError):
next(parser)
def test_missing_rp():
parser = parse(iter([lp, rp, lp, lp, rp]))
assert next(parser) is NIL
with pytest.raises(SyntaxError):
next(parser)
def test_valid_parses(ast):
assert list(parse(deparse(ast))) == ast