#     Copyright 2016, Kay Hayen, mailto:kay.hayen@gmail.com
#
#     Python tests originally created or extracted from other peoples work. The
#     parts were too small to be protected.
#
#     Licensed under the Apache License, Version 2.0 (the "License");
#     you may not use this file except in compliance with the License.
#     You may obtain a copy of the License at
#
#        http://www.apache.org/licenses/LICENSE-2.0
#
#     Unless required by applicable law or agreed to in writing, software
#     distributed under the License is distributed on an "AS IS" BASIS,
#     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#     See the License for the specific language governing permissions and
#     limitations under the License.
#
from __future__ import print_function

def displayDict(d):
    result = '{'
    for key, value in sorted(d.items()):
        result += "%s: %s" % (key, value)
    result += '}'

print("List contraction on the module level:")
x = [(u if u%2==0 else 0) for u in range(10)]
print(x)

print("List contraction on the function level:")
def someFunction():
    x = [(u if u%2==0 else 0) for u in range(10)]
    print(x)

someFunction()

print("List contractions with no, 1 one 2 conditions:")
def otherFunction():
    print([ x for x in range(8) ])
    print([ x for x in range(8) if x % 2 == 1 ])
    print([ x for x in range(8) if x % 2 == 1 if x > 4 ])

otherFunction()

print("Complex list contractions with more than one for:")
def complexContractions():
    print([ (x,y) for x in range(3) for y in range(5) ])

    seq = range(3)
    res = [(i, j, k) for i in iter(seq) for j in iter(seq) for k in iter(seq)]

    print(res)

complexContractions()

print("Contraction for 2 for statements and one final if referring to first for:")

def trickyContraction():
    class Range:
        def __init__(self, value):
            self.value = value

        def __iter__(self):
            print("Giving range iter to", self.value)

            return iter(range(self.value))

    def Cond(y):
        print("Checking against", y)

        return y == 1

    r = [ (x,z,y) for x in Range(3) for z in Range(2) for y in Range(4) if Cond(y) ]
    print("result is", r)

trickyContraction()

def lambdaWithcontraction(x):
    l = lambda x : [ z for z in range(x) ]
    r = l(x)

    print("Lambda contraction locals:", displayDict(locals()))

lambdaWithcontraction(3)

print("Contraction that gets a 'del' on the iterator variable:", end = ' ')

def allowedDelOnIteratorVariable(z):
    x = 2
    del x
    return [ x*z for x in range(z) ]

print(allowedDelOnIteratorVariable(3))
