Adding to the manual gensym for macros are 2 new
macros, but very literal from the CL in
letoverlambda.
The first is the (with-gensyms ...) macro that
can generate a small set of syms for a macro. Works
something like:
(defmacro adder2 [A B]
(with-gensyms [a b]
`(let [[~a ~A] [~b ~B]]
(+ ~a ~b))))
and ~a and ~b will be replaced with (gensym "a") and
(gensym "b") respectively.
Then the final macro is a new defmacro that will automatically
replace symbols prefaced with "g!" with a new gensym based on the
rest of the symbol. So in this final version of 'nif':
(defmacro/g! nif4 (expr pos zero neg)
`(let [[~g!result ~expr]]
(cond [(pos? ~g!result) ~pos]
[(zero? ~g!result) ~zero]
[(neg? ~g!result) ~neg])))
all uses of ~g!result will be replaced with (gensym "result").
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
This rounds out the first pass at a set of core functions, adding
some that were not in the first PR.
From here I'm working on a contrib.seq and contrib.io module to
hold less obvious but maybe interesting native functions that can
move to core if desired.
This should also close out issure #150 asking for some core
functions like these.
Updated most methods to replace While with For, and added tons of new tests
for things like (cycle []) and lists with None's in them.
thanks @olasd
Add set of new core functions
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.
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.
