pseudosugar 2010.01.01.README

DESCRIPTION: pseudosugar - extend python with functional programming language features

REQUIRES: LINUX OS AND PYTHON3.1

QUICK TEST: $ python3.1 setup.py build dev –quicktest

SUMMARY: pseudosugar is a pure python module. pseudosugar is a python ast tree hack, adding the following syntax sugars:

function<<<< aa, bb, cc, … -> function(aa, bb, cc, …) aa, bb, cc, … >>>>function -> function(aa, bb, cc, …)

xx ..function(aa, bb, cc) -> function(xx, aa, bb, cc) xx …function(aa, bb, cc) -> function(aa, xx, bb, cc) xx ….function(aa, bb, cc) -> function(aa, bb, xx, cc)

RECENT CHANGELOG:

20091231 - added <<<< and >>>> sugar 20091224 - added pseudomethod interactive console - revamped pseudomethod import hook 20091224 - modularized package - fix install issues - added sdist check 20091209 - improved documentation 20091205 - moved source code to c++ 20091116 - package integrated

DEMO USAGE:

>>> ## start up the interactive console
>>> from pseudosugar import *
>>> pseudo_console().interact()

Python 3.1.1 (r311:74480, Sep 13 2009, 17:17:12) [GCC 4.3.2] on linux2 Type “help”, “copyright”, “credits” or “license” for more information. (pseudo_console) pseudo_importer - adding hook <pseudosugar.pseudo_importer object at 0xb7ac754c> to sys.meta_path >>> from pseudosugar import *

>>> #### QUICK EXAMPLES
>>> ## prefix operator
>>> print<<<< 'hello', 'world'
hello world

>>> ## postfix operator
>>> 'hello', 'world' >>>>print
hello world

>>> ## pseudomethod
>>> def function(aa, bb, cc): return (aa, bb, cc)
>>> 1 ..function(0, 0) >>>>print
(1, 0, 0)
>>> 2 ...function(0, 0) >>>>print
(0, 2, 0)
>>> 3 ....function(0, 0) >>>>print
(0, 0, 3)

>>> ## '<<<<' CONVERTS FUNCTIONS INTO PREFIX OPERATORS
>>> ## foo<<<< turns foo into a prefix operator
>>> ## foo<<<< will take in everything to its right that is comma delimited
>>> ## print<<<< is useful for making print statements
>>> print<<<< 'bob says', 'hello ' + re.sub<<<< re.compile('(\w+)'), '\\1!', 'world'
bob says hello world!

>>> ## '>>>>' CONVERTS FUNCTIONS INTO POSTFIX OPERATORS
>>> ## it behaves almost exactly like '>>>>' except in reverse
>>> ## it is useful for chaining together multiple operators
>>> 'qwerty' >>>>list >>>>sorted >>>>enumerate >>>>dict >>>>print
{0: 'e', 1: 'q', 2: 'r', 3: 't', 4: 'w', 5: 'y'}

>>> ## OPERATOR PRECEDENCE
>>> ## '>>>>' has higher operator precedence than '<<<<'
>>> print( list<<<< 'abcd' >>>>tuple ) ## list(tuple('abcd'))
['a', 'b', 'c', 'd']

>>> #### PSEUDOMETHOD SYNTAX
>>> ## DYNAMICALLY BIND FUNCTION CALLS TO OBJECTS
>>> ## bind the function call print() to 'hello'
>>> print('hello')
hello
>>> 'hello' ..print()
hello
>>> 'hello' ..print('world')
hello world
>>> 'hello' ..print('world', '!')
hello world !
>>> 'hello' ..print('world', '!', file = sys.stdout)
hello world !

>>> ## create a string pseudomethod which adds an exclamation or other endings
>>> def add_ending(self, end = '!'): return self + end
>>> 'hello' ..add_ending() ..print()
hello!
>>> 'hello'.upper() ..add_ending() ..print()
HELLO!
>>> 'hello'.upper() ..add_ending(' world') ..print()
HELLO world
>>> 'hello'.upper() ..add_ending(' world').lower() ..print()
hello world
>>> 'hello'.upper() ..add_ending(' world').lower() ..add_ending('!') ..print()
hello world!
>>> 'hello'.upper() ..add_ending(' world').lower() ..add_ending('!') ..add_ending(end = '!') ..print()
hello world!!

>>> ## OPERATOR PRECEDENCE
>>> ## 'aa ..bb()' has the same operator precedence as the attribute operator 'a.b'
>>> def add(aa, bb): return aa + bb
>>> print( 2 * 3 ..add(4) + 5 == 2 * (3 + 4) + 5 )
True
>>> print( 3 == 1 ..add(2) )
True
>>> print( 0, 0 ..add(1), 0 )
0 1 0

>>> ## EXTEND RESTRICTED TYPES
>>> ## the python code object type <class 'code'> cannot be subtyped nor will it accept any method binding.
>>> ## however, we can extend it by dynamically binding ordinary functions.
>>> ## here's a pseudomethod which disassembles an instance of the type to a specified output
>>> import dis, io, sys
>>> def disassemble(self, file):
...   backup_stdout = sys.stdout ## backup sys.stdout
...   try:
...     sys.stdout = file
...     dis.dis(self) ## disassemble self
...     return file
...   finally:
...     sys.stdout = backup_stdout ## restore sys.stdout

>>> code_source = 'print( "hello" )'; code_object = compile(code_source, '', 'exec'); exec( code_object )
hello
>>> code_object ..disassemble(file = io.StringIO()).getvalue() ..print()
  1           0 LOAD_NAME                0 (print)
              3 LOAD_CONST               0 ('hello')
              6 CALL_FUNCTION            1
              9 POP_TOP
             10 LOAD_CONST               1 (None)
             13 RETURN_VALUE

>>> ## '...' AND '....' SYNTAX
>>> ## sometimes we instead want the 2nd or 3rd argument of a function bound to an object.
>>> ## '...' and '....' will do this respectively
>>> '2nd' ...print(0, 0)
0 2nd 0
>>> '3rd' ....print(0, 0)
0 0 3rd

>>> ## '....' is useful for chaining re.sub
>>> ss = 'file = io.StringIO(); print 1, 2, 3 >> file; print file.getvalue()'; print( ss )
file = io.StringIO(); print 1, 2, 3 >> file; print file.getvalue()

>>> print(
...   re.sub('print (.*?)$', 'print( \\1 )',
...          re.sub('print (.*) >> (.*?);', 'print( \\1, file = \\2 );', ss)
...          )
...   )
file = io.StringIO(); print( 1, 2, 3, file = file ); print( file.getvalue() )

>>> ss ....re.sub('print (.*) >> (.*?);', 'print( \\1, file = \\2 );') \
...    ....re.sub('print (.*?)$', 'print( \\1 )') \
...    ..print()
file = io.StringIO(); print( 1, 2, 3, file = file ); print( file.getvalue() )

>>> ## in fact, another primary use of pseudomethod is to flatten ugly, hard-to-read, lisp-like nested function calls
>>> print( dict( enumerate( zip( 'abc',  sorted( 'abc bca cab'.split(' '), key = lambda x: x[1] ) ) ) ) )
{0: ('a', 'cab'), 1: ('b', 'abc'), 2: ('c', 'bca')}

>>> 'abc bca cab'.split(' ') ..sorted(key = lambda x: x[1]) ...zip('abc') ..enumerate() ..dict() ..print()
{0: ('a', 'cab'), 1: ('b', 'abc'), 2: ('c', 'bca')}

>>> ## IMPORT MODULES WRITTEN WITH PSEUDOMETHOD SYNTAX
>>> ## create test_module.py
>>> open('test_module.py', 'w').write('"hello" ..print()\n') ..print('bytes written')
18 bytes written

>>> ## during import, insert the magic prefix 'pseudosugar.' before the last module
>>> ## import pseudosugar.a
>>> ## import a.pseudosugar.b
>>> ## import a.b.pseudosugar.c
>>> import pseudosugar.test_module
hello