302 lines
6.7 KiB
Python
Raw Permalink Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

# -*- coding: utf8 -*-
"""
.. module:: lesscpy.lessc.utility
:synopsis: various utility functions
Copyright (c)
See LICENSE for details.
.. moduleauthor:: Johann T. Mariusson <jtm@robot.is>
"""
from __future__ import print_function
import collections
import itertools
import math
import re
import sys
def flatten(lst):
"""Flatten list.
Args:
lst (list): List to flatten
Returns:
generator
"""
for elm in lst:
if isinstance(elm, collections.Iterable) and not isinstance(elm, str):
for sub in flatten(elm):
yield sub
else:
yield elm
def pairwise(lst):
""" yield item i and item i+1 in lst. e.g.
(lst[0], lst[1]), (lst[1], lst[2]), ..., (lst[-1], None)
Args:
lst (list): List to process
Returns:
list
"""
if not lst:
return
length = len(lst)
for i in range(length - 1):
yield lst[i], lst[i + 1]
yield lst[-1], None
def rename(blocks, scope, stype):
""" Rename all sub-blocks moved under another
block. (mixins)
Args:
lst (list): block list
scope (object): Scope object
"""
for p in blocks:
if isinstance(p, stype):
p.tokens[0].parse(scope)
if p.tokens[1]:
scope.push()
scope.current = p.tokens[0]
rename(p.tokens[1], scope, stype)
scope.pop()
def blocksearch(block, name):
""" Recursive search for name in block (inner blocks)
Args:
name (str): search term
Returns:
Block OR False
"""
if hasattr(block, 'tokens'):
for b in block.tokens[1]:
b = (b if hasattr(b, 'raw') and b.raw() == name
else blocksearch(b, name))
if b:
return b
return False
def reverse_guard(lst):
""" Reverse guard expression. not
(@a > 5) -> (@a =< 5)
Args:
lst (list): Expression
returns:
list
"""
rev = {
'<': '>=',
'>': '=<',
'>=': '<',
'=<': '>'
}
return [rev[l] if l in rev else l for l in lst]
def debug_print(lst, lvl=0):
""" Print scope tree
args:
lst (list): parse result
lvl (int): current nesting level
"""
pad = ''.join(['\t.'] * lvl)
t = type(lst)
if t is list:
for p in lst:
debug_print(p, lvl)
elif hasattr(lst, 'tokens'):
print(pad, t)
debug_print(list(flatten(lst.tokens)), lvl + 1)
def destring(value):
""" Strip quotes from string
args:
value (str)
returns:
str
"""
return value.strip('"\'')
def analyze_number(var, err=''):
""" Analyse number for type and split from unit
1px -> (q, 'px')
args:
var (str): number string
kwargs:
err (str): Error message
raises:
SyntaxError
returns:
tuple
"""
n, u = split_unit(var)
if not isinstance(var, str):
return (var, u)
if is_color(var):
return (var, 'color')
if is_int(n):
n = int(n)
elif is_float(n):
n = float(n)
else:
raise SyntaxError('%s ´%s´' % (err, var))
return (n, u)
def with_unit(number, unit=None):
""" Return number with unit
args:
number (mixed): Number
unit (str): Unit
returns:
str
"""
if isinstance(number, tuple):
number, unit = number
if number == 0:
return '0'
if unit:
number = str(number)
if number.startswith('.'):
number = '0' + number
return "%s%s" % (number, unit)
return number if isinstance(number, str) else str(number)
def is_color(value):
""" Is string CSS color
args:
value (str): string
returns:
bool
"""
if not value or not isinstance(value, str):
return False
if value[0] == '#' and len(value) in [4, 5, 7, 9]:
try:
int(value[1:], 16)
return True
except ValueError:
pass
return False
def is_variable(value):
""" Check if string is LESS variable
args:
value (str): string
returns:
bool
"""
if isinstance(value, str):
return (value.startswith('@') or value.startswith('-@'))
elif isinstance(value, tuple):
value = ''.join(value)
return (value.startswith('@') or value.startswith('-@'))
return False
def is_int(value):
""" Is value integer
args:
value (str): string
returns:
bool
"""
try:
int(str(value))
return True
except (ValueError, TypeError):
pass
return False
def is_float(value):
""" Is value float
args:
value (str): string
returns:
bool
"""
if not is_int(value):
try:
float(str(value))
return True
except (ValueError, TypeError):
pass
return False
def split_unit(value):
""" Split a number from its unit
1px -> (q, 'px')
Args:
value (str): input
returns:
tuple
"""
r = re.search('^(\-?[\d\.]+)(.*)$', str(value))
return r.groups() if r else ('', '')
def away_from_zero_round(value, ndigits=0):
"""Round half-way away from zero.
Python2's round() method.
"""
if sys.version_info[0] >= 3:
p = 10 ** ndigits
return float(math.floor((value * p) + math.copysign(0.5, value))) / p
else:
return round(value, ndigits)
def convergent_round(value, ndigits=0):
"""Convergent rounding.
Round to neareas even, similar to Python3's round() method.
"""
if sys.version_info[0] < 3:
if value < 0.0:
return -convergent_round(-value)
epsilon = 0.0000001
integral_part, _ = divmod(value, 1)
if abs(value - (integral_part + 0.5)) < epsilon:
if integral_part % 2.0 < epsilon:
return integral_part
else:
nearest_even = integral_part + 0.5
return math.ceil(nearest_even)
return round(value, ndigits)
def pc_or_float(s):
""" Utility function to process strings that contain either percentiles or floats
args:
str: s
returns:
float
"""
if isinstance(s, str) and '%' in s:
return float(s.strip('%')) / 100.0
return float(s)
def permutations_with_replacement(iterable, r=None):
"""Return successive r length permutations of elements in the iterable.
Similar to itertools.permutation but withouth repeated values filtering.
"""
pool = tuple(iterable)
n = len(pool)
r = n if r is None else r
for indices in itertools.product(range(n), repeat=r):
yield list(pool[i] for i in indices)