def balanced_braces(gen):
print u'balanced braces start'
count = 0
lexemes = []
while True:
lexemes.append(gen.parse(alt(any, EOF)))
tokid = lexemes[-1].get_token().tokid
if tokid == Token.LBRACK:
count += 1
print u'incr count to: %d' % count
elif tokid == Token.RBRACK:
if count <= 0:
gen.fail(u'balanced braces')
count -= 1
print u'decr count to: %d' % count
elif count == 0 and tokid in [Token.NL, Token.EOF]:
print u'balanced braces end'
return Box.List(lexemes)
def pattern(gen):
return gen.parse(alt(var_pattern, tag_pattern, named_pattern, paren_pattern))
def expr(gen):
box = gen.parse(alt(definition, chain).many())
elements = [a.get_ast() for a in box.get_list()]
return ASTBox(Sequence(elements))
def atom(gen):
return gen.parse(alt(var, number, paren, lam, tag, autovar))
def module_item(gen):
return gen.parse(alt(definition, unparsed_annotation))
out[i+1] = rest[i].get_ast()
return ASTBox(Chain(out))
@generate
def definition(gen):
box = gen.parse(assign).get_list()
name = box[0].get_token().value
args = [a.get_ast() for a in box[1].get_list()]
body = gen.parse(chain).get_ast()
return ASTBox(Definition(sym(name), args, body))
expr_element = alt(chain, definition)
@generate
def expr(gen):
box = gen.parse(alt(definition, chain).many())
elements = [a.get_ast() for a in box.get_list()]
return ASTBox(Sequence(elements))
@generate('pattern')
def pattern(gen):
return gen.parse(alt(var_pattern, tag_pattern, named_pattern, paren_pattern))
paren_pattern = LPAREN.then(pattern).skip(RPAREN)
var_pattern = NAME.map(lambda s: ASTBox(VarPat(sym(s.get_token().value))))
