Python Macros: Use Cases?

Question

If Python had a macro facility similar to Lisp/Scheme (something like MetaPython), how would you use it?

If you are a Lisp/Scheme programmer, what sorts of things do y

Answer 1

Hy, For my own use, I created a Python module (Espy) that allows macro definitions with arguments, loop and conditional code generation: You create a source.espy file, then launch the appropriate function, then source.py is generated.

It allows syntaxes as following:

macro repeat(arg1):
    for i in range(%arg1%):
        socket
    print "stop"
   ...
repeat(5):
    print "Hi everybody"
    print "See you soon"

is equivalent to:

...
for i in range(5):
    print "Hi everybody"
    print "See you soon"
print "stop"

Other syntax:

macro doit(arg1):
    for i in %arg1%:
        socket suit(arg2):
            socket
            print %arg2%
        socket check(arg3):
            if %arg2%==%arg3%:
                socket
...
#use
doit(range(10)):
    suit(result):
        result=i*i
    check(result,25):
        print "I knew that 5*5 == 25"

is equivalent to:

for i in range(10):
    result=i*i
    print result
    if result==25:
        print "I knew that 5*5 == 25"

More, Espy has 2 functions: "macro for" and "macro if". An example:

macro for v in [6,10,12,20,23]:
    macro if 7<%v%<22:
        True:
            print "At %v%, I'm awake."
        False:
            print "At %v%, I'm sleeping."

is translated by Espy in:

print "At 6, I'm sleeping."
print "At 10, I'm awake."
print "At 12, I'm awake."
print "At 20, I'm awake."
print "At 23, I'm sleeping."

Complete documentation and free download can be found here: http://elp.chronocv.fr

I use this module in many cases. It permits more structured and shorter codes. With it I generated 65000 lines of clear and efficient python code from 1000 lines of espy code for a new chess engine project (still in progress).

If Python could include macros in futur release, it'd become more impressive.