Commit Graph

63 Commits

Author SHA1 Message Date
Bob Tolbert
f5d88bb108 gensym in Hy
Simple implementation of gensym in Hy.

Returns a new HySymbol.

Usable in macros like:

(defmacro nif [expr pos zero neg]
  (let [[g (gensym)]]
    `(let [[~g ~expr]]
       (cond [(pos? ~g) ~pos]
             [(zero? ~g) ~zero]
             [(neg? ~g) ~neg]))))

This addresses all the general comments about (gensym), and doesn't
try to implement "auto-gensym" yet. But clearly the macro approach
instead of the pre-processor approach (as described in the
letoverlambda (http://letoverlambda.com/index.cl/guest/chap3.html#sec_5)
is the way to go
2013-12-15 12:36:36 -07:00
Abhishek L
f1c68bd51a Allow macros to return None, fixes #357
Allows Hy macros to return None, to test this

  (defmacro foo [])
  (foo)

Should work now
2013-12-06 00:27:45 +05:30
Konrad Hinsen
b11f2fcf49 Macro if-python2 for compile-time choice between Python 2 and Python 3 code branches 2013-09-02 09:58:35 +02:00
Paul Tagliamonte
1c12b2870e Add yield from via macro magic.
This will let us use (basic) yield from behavior from Python 2. This
 isn't complete, and is low-hanging fruit for others willing to hack
 on hy.

 I've also changed the macrosystem to allow for proper bootstrapping.
 This is similar to how it's done elsewhere in the codebase (stdlib
 stuff).
2013-08-17 11:37:48 -04:00
Paul Tagliamonte
7c91913122 Fix yielding to not suck (#151)
This adds a class to avoid returning when we have a Yieldable
 expression contained in the body of the function. This breaks Python
 2.x, and ought to break Python 3.x, but doesn't.

 We need this fo' context managers, etc.

 This commit also has work from @rwtolbert adding new testcases and
 fixes for yielded entries behind a while / for.
2013-07-14 13:11:27 -04:00
Konrad Hinsen
2674016d3d More tests 2013-06-07 16:36:04 +02:00
Konrad Hinsen
6eacf63b53 Provide both eval-and-compile and eval-when-compile 2013-06-07 16:36:04 +02:00
Konrad Hinsen
80105d9731 eval-when-compile permits compile-time definitions that can be used from macros 2013-06-07 16:36:04 +02:00
Konrad Hinsen
12abef5ed5 Forgot boolean constants.. 2013-06-07 16:35:28 +02:00
Konrad Hinsen
e47bac1f96 Permit macros to return constants 2013-06-05 12:19:06 +02:00
Nicolas Dandrimont
1e7c90c44e Test requires from native code 2013-05-11 21:25:21 +02:00
Nicolas Dandrimont
bd478590fa Make that test macro more lispy 2013-05-11 21:25:21 +02:00
Nicolas Dandrimont
0bbce2a819 Add a native macros test 2013-05-11 19:40:48 +02:00