MacroPy 1.0.1

Macros for Python: Quasiquotes, Case Classes, LINQ and more!

MacroPy is an implementation of Macros in the Python Programming Language. MacroPy provides a mechanism for user-defined functions (macros) to perform transformations on the abstract syntax tree(AST) of Python code at module import time. This is an easy way to modify the semantics of a python program

Python like you’ve never seen before

MacroPy allows you to create constructs which are impossible to have in normal python code, such as:

Tracing

with trace:
    sum([x + 5 for x in range(3)])

# sum([x + 5 for x in range(3)])
# range(3) -> [0, 1, 2]
# x + 5 -> 5
# x + 5 -> 6
# x + 5 -> 7
# [x + 5 for x in range(3)] -> [5, 6, 7]
# sum([x + 5 for x in range(3)]) -> 18

Quick Lambdas

print map(f[_[0]], ['omg', 'wtf', 'bbq'])
# ['o', 'w', 'b']

print reduce(f%[_ + _], ['omg', 'wtf', 'bbq'])
# 'omgwtfbbq

Case Classes

@case
class Point(x, y): pass

p = Point(1, 2)

print str(p)    #Point(1, 2)
print p.x       #1
print p.y       #2
print Point(1, 2) == Point(1, 2) # True

And more! All this runs perfectly on vanilla Python 2.7 or PyPy 2.0. For more details, see the GitHub page.