Like other lisps, operators `+` and `*` return their identity values
when called with no arguments. Also with a single operand they return
the operand.
This fixes#372
There was a couple of duplicate imports and type checkings in the
codebase. So I added a new module to unify all Python 2 and 3
compatibility codes.
Also, this is a somewhat common pattern in Python. See Jinja2 for
example:
https://github.com/mitsuhiko/jinja2/blob/master/jinja2/_compat.py
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.
Add set of new core functions to the stdlib.
Moved the auto-import code from compile_expression to
HySymbol so that "even?' in this style expression will
be found and imported.
(list (filter even? [1 2 3 4 5]))
The core functions are documented in 2 sections, one
for basic functions like (even?..) and (nth ...) and
one for all the sequence functions.
Update: This removes all the caching decorators, misnamed as
'lazy-seq' from the core. All sequence methods now just use
yield to return a generator, so they are Python-lazy
Further refinements of core functions
Cleaned up the docs to use 'iterator' instead of 'generator'
Fixed drop to just return the iterator instead of an extra
yield loop. But also added a test to catch dropping too
many.
This will let us implement common functions seen in other lisps,
and allow them to be importable, without explicit imports. The goal
is to keep this as small as we can; we don't want too much magic.
I've added `take' and `drop' as examples of what we can do.
A macro is available in the module where it was defined and
in any module that does a require of the defining module.
Only macros defined in hy.core are globally available.
Fixes#181
