lawvere 0.1

• Installation
• Usage
• Development

安装

从pypi安装：

pip install lawvere

或来源：

git clone git@github.com:apieum/lawvere.git
cd lawvere
python setup.py install

用法

快速入门：

for impatients

arrow只接受两个可选参数：

• domain或source：它是类型的元组（如果是1元组，则仅是类型）
• 共域或target：（单一类型）

它返回一个函数装饰器

语法与Python2.7到3.x兼容。 如果只针对3.x版本，则可以使用注释而不是“arrow”参数。 “arrow”参数覆盖注释。

与2.x和3.x python版本兼容的代码。

fromlawvereimportarrow# obviously you don't need to use named parameters# it's just to illustrate their meaning.@arrow(domain=(int,int),codomain=int)defadd(x,y):returnx+y# currying:add2=add(2)assertadd2(3)==5assertadd(1)(2)==3# successive calls# composition (pipe):# pass the result of first function to secondadd4=add2>>add2assertadd4(1)==5# composition (circle):# pass result of add(1) into add4add5=add4<<add(1)assertadd5(5)==10# composed functions are tuples:assertisinstance(add4,tuple)assertadd5[1]==add4# equality is checked over signatures:assertadd(1)==add(1)assertadd5==add(1)>>add2>>add2# operator precedence:assertadd5==add(1)>>(add2<<add2)assertadd5==add2>>add2<<add(1)# Type Checking:type_checked=Falsetry:add('a','b')=='ab'exceptTypeError:type_checked=Trueasserttype_checked,'add should not exists for str types'# dispatch register# concat inherit arrow properties@add.register((str,str),str)defconcat(x,y):return"%s%s"%(x,y)# can still call/curry... concatassertconcat('a')('b')=='a b'# add with str call concatassertadd('a')==concat('a')# Concat is only defined for strtype_checked=Falsetry:assertconcat(1,2)==3exceptTypeError:type_checked=Trueasserttype_checked,'concat should not exists for int types'# Type Checking when composing:try:add>>concat(y='b')exceptTypeErrorasexc:message=str(exc)# hope message is clear :)assertmessage=="Cannot compose add -> int with concat(x:str=Undefined, y:str=b)"# if composition was circle message would be:# ... concat -> str with add(x:int=Undefined, y:int=Undefined)

代码仅与3.x版本兼容。

fromlawvereimportarrow@arrowdefadd(x:int,y:int)->int:returnx+y# identical use as Python 2 ## Type Checking:type_checked=Falsetry:add('a','b')=='ab'exceptTypeError:type_checked=Trueasserttype_checked,'add should not exists for str types'# dispatch@add.registerdefconcat(x:str,y:str)->str:return"%s%s"%(x,y)assertconcat('a','b')=='a b'# now add exists for str types:assertadd('a','b')=='a b'# type is also checked when composing... see python 2 ex.

开发

感谢您的反馈、代码评审、改进或错误，以及文档帮助。 你可以通过邮件联系我：apieum[在]gmail[点]com

测试建议要求：

pip install -r dev-requirements.txt

有时-规格颜色不起作用。卸载nosespec和nosecolor，然后按此顺序分别重新安装nosecolor和nosespec（先安装nosecolor）

启动测试：

git clone git@github.com:apieum/lawvere.git
cd lawvere
nosetests --with-spec --spec-color ./lawvere
# or with watch
# nosetests --with-spec --spec-color --with-watch ./lawvere