def _prepare_schema_coercer_global_cache():
'''Prepare global cache for scheme coercer.'''
from xoutil import Undefined
from xoutil.eight import zip
from xoutil.values import (coercer as checker_coerce,
iterable,
identity_coerce, identifier_coerce,
positive_int_coerce)
pos_coerce = iterable(positive_int_coerce, outer_coerce=set)
alias_coerce = iterable(identifier_coerce, outer_coerce=set)
default_coerce = identity_coerce
checker_default = identity_coerce
pos_default = set()
alias_default = set()
default_default = Undefined
names = ('checker', 'pos', 'aliases', 'default')
coercers = dict(zip(names, (checker_coerce, pos_coerce, alias_coerce,
default_coerce)))
defaults = dict(zip(names, (checker_default, pos_default, alias_default,
default_default)))
return (names, coercers, defaults)
def findlinestarts(code):
"""Find the offsets in a byte code which are start of lines in the source.
Generate pairs (offset, lineno) as described in Python/compile.c.
"""
from xoutil.eight import zip
byte_increments = [_ord(x) for x in code.co_lnotab[0::2]]
line_increments = [_ord(x) for x in code.co_lnotab[1::2]]
lastlineno = None
lineno = code.co_firstlineno
addr = 0
for byte_incr, line_incr in zip(byte_increments, line_increments):
if byte_incr:
if lineno != lastlineno:
yield (addr, lineno)
lastlineno = lineno
addr += byte_incr
lineno += line_incr
if lineno != lastlineno:
yield (addr, lineno)
