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letexpr 0.3.5

imitation of let expression like a Haskell.

[![Build Status]https://travis-ci.org/hachibeeDI/letexpr.png?branch=master]https://travis-ci.org/hachibeeDI/letexpr

# letexpr

That is python module imitate `let expression` like a Haskell.

And support lazy evaluation.


# Installation

```bash
$ pip install https://github.com/hachibeeDI/letexpr/archive/master.zip
```


# Example

```python
from letexpr import let, expr

# expr(x) = lambda x: lambda: x

answer = (
let()
| ('x', expr(10))
| ('y', expr(20))
| ('size', lambda x, y: x * y)
| ('hoge', lambda x, y: 'fooo')
).in_(lambda x, y, size:
'x = {x}, y = {y}, x * y = {size}'.format(x=x, y=y, size=size))
print answer
# => 'x = 10, y = 20, x * y = 200'


# with List Comprehensions
even_or_odd = [
(let()
| ('_i', expr(str(i)))
| ('r', expr('even' if i % 2 == 0 else 'odd'))
).in_(lambda _i, r:
_i + ' is an ' + r + ' number.')
for i in range(1, 5)]
print even_or_odd
# => ['1 is odd number.', '2 is even number.', '3 is odd number.', '4 is even number.']


# with anonymous function
let_ = (let()
| ('x', expr('x'))
| ('y', expr('y'))
)
@let_.in_()
def _(x, y):
return x + y
print let_.end
# => 'xy'

```

# Testing


```bash
$ pip install nose
$ nosetests --with-doctest
```  
File Type Py Version Uploaded on Size
letexpr-0.3.5.tar.gz (md5) Source 2014-07-14 3KB
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  • Author: OGURA_Daiki
  • Home Page: https://github.com/hachibeeDI/letexpr
  • Keywords: let,expression
  • License:
    The MIT License (MIT)
    
    Copyright (c) 2014 OGURA Daiki
    
    Permission is hereby granted, free of charge, to any person obtaining a copy
    of this software and associated documentation files (the "Software"), to deal
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    The above copyright notice and this permission notice shall be included in all
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    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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