def test_lookahead(self):
x = t.Lookahead(t.Exactly("x"))
self.assertEqual(writeBytecode(x),
[t.Choice(7),
t.Choice(4),
t.Match('x'),
t.Commit(1),
t.Fail(),
t.Commit(1),
t.Fail()])
def test_tripleOr(self):
xy = t.Or([t.Exactly("x"), t.Exactly("y"), t.Exactly("z")])
self.assertEqual(writeBytecode(xy), [
t.Choice(3),
t.Match('x'),
t.Commit(5),
t.Choice(3),
t.Match('y'),
t.Commit(2),
t.Match('z')
])
def generate_Lookahead(self, out, expr, debugname=None):
L1 = out.emit(t.Choice())
L2 = out.emit(t.Choice())
self._generateNode(out, expr)
L3 = out.emit(t.Commit(), label=L2)
out.emit(t.Fail(), label=L3)
out.patchNext(L1)
def test_optional(self):
x = t.Optional(t.Exactly("x"))
self.assertEqual(writeBytecode(x),
[t.Choice(3),
t.Match('x'),
t.Commit(2),
t.Python("None")])
def test_many1(self):
xs = t.Many1(t.Exactly("x"))
self.assertEqual(writeBytecode(xs),
[t.Match('x'),
t.Choice(3),
t.Match('x'),
t.Commit(-2)])
def test_not(self):
x = t.Not(t.Exactly("x"))
self.assertEqual(writeBytecode(x),
[t.Choice(4),
t.Match('x'),
t.Commit(1),
t.Fail()])
def generate_Optional(self, out, expr, debugname=None):
"""
Try to parse an expr and continue if it fails.
"""
L = out.emit(t.Choice())
self._generateNode(out, expr, debugname)
L2 = out.emit(t.Commit())
out.emit(t.Python("None"), label=L)
out.patchNext(L2)
def generate_Repeat(self, out, min, max, expr, debugname=None):
out.emit(t.Python(str(min.data)))
out.emit(t.Push())
out.emit(t.Python(str(max.data)))
out.emit(t.Push())
L = out.emit(t.RepeatChoice())
self._generateNode(out, expr, debugname)
L2 = out.emit(t.Commit())
out.patchNext(L)
out.backpatch(L2, L)
def test_repeat(self):
x = t.Repeat(3, 4, t.Exactly('x'))
self.assertEqual(writeBytecode(x),
[t.Python("3"),
t.Push(),
t.Python("4"),
t.Push(),
t.RepeatChoice(3),
t.Match('x'),
t.Commit(-2)])
def generate_Or(self, out, exprs, debugname=None):
if len(exprs.args) == 1:
self._generateNode(out, exprs.args[0])
return
L = None
lcs = []
for ex in exprs.args[:-1]:
L = out.emit(t.Choice(), label=L)
self._generateNode(out, ex)
lcs.append(out.emit(t.Commit()))
out.patchNext(L)
self._generateNode(out, exprs.args[-1])
for LC in lcs:
out.patchNext(LC)
def generate_Not(self, out, expr, debugname=None):
L1 = out.emit(t.Choice())
self._generateNode(out, expr)
L2 = out.emit(t.Commit())
out.emit(t.Fail(), label=L1)
out.patchNext(L2)
def generate_Many(self, out, expr, debugname=None):
L = out.emit(t.Choice())
self._generateNode(out, expr, debugname)
L2 = out.emit(t.Commit())
out.patchNext(L)
out.backpatch(L2, L)
