As a result:
* functions such as `nth` should work correctly on iterators;
* `nth` will raise `IndexError` (in a fashion consistent with `get`)
when the index is out of bounds;
* `take`, etc. will raise `ValueError` instead of returning
an ambiguous value if the index is negative;
* `map`, `zip`, `range`, `input`, `filter` work the same way (Py3k one)
on both Python 2 and 3 (see #523 and #331).
Also small DRYing in try handling.
Previously, writing a bare (try (foo)) would invoke Pokemon
exception catching (gotta catch 'em all) instead of the correct
behavior, which is to raise the exception if no handler is provided.
Note that this is a cute feature of Hy, as a `try` with no `except`
is a syntax error. We avoid the syntax error here because we don't
use Python's compiler, which is the only thing that can throw
Syntax Errors. :D
Fixes#555.
The yield-from that existed previously wasn't actually implementing the
full complexity of "yield from":
http://legacy.python.org/dev/peps/pep-0380/#formal-semantics
... this includes passing along errors, and many other things.
Also removes the yield-from backport macro, since it does not seem
possible at present to conditionally build macros.
Thus, there is no longer yield-from on pre-python-3.3 systems.
Includes updated docs and tests to reflect all this.
One would expect the form:
> (defmacro a (&rest b) b)
> (a 1 2)
To return a tuple object but we have no Hy model so it returns a HyList.
Not sure if this is the right thing to do.
When (import) encounters anything but a HySymbol or HyList, raise an
exception, as that is not valid in Hy. Previously, anything other than a
HySymbol or HyList was simply ignored, turning that particular import
into a no-op, which was both wrong and confusing.
Reported-by: Richard Parsons <richard.lee.parsons@gmail.com>
Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
This function will recursively perform all possible macroexpansions in
the supplied form. Unfortunately, it also traverses into quasiquoted
parts, where it shouldn't, but it is a useful estimation of macro
expansion anyway.
Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
The hy.contrib.walk module provides a few functions to walk the Hy AST,
and potentially transform it along the way. The main entry point
is (walk), which takes two functions and a form as arguments, and
applies the first (inner) function to each element of the form, building
up a data structure of the same type as the original. Then applies outer
(the second function) to the result.
Two convenience functions are provided: (postwalk) and (prewalk), which
do a depth-first, post/pre-order traversal of the form.
Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
* hy/core/language.hy: Adding a simple `identity` function that returns
the argument supplied to it
* docs/language/core.rst: Updated docs with identity function
Sometimes it is better to start with the false condition, sometimes that
makes the code clearer. For that, the (if-not) macro, which simply
reverses the order of the condition blocks, can be of great use.
Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
In the same vein as defmacro-alias, this implements defn-alias /
defun-alias, which does essentially the same thing as defmacro-alias,
but for functions.
Signed-off-by: Gergely Nagy <algernon@balabit.hu>
With this patch, every identifier is split up along dots, each part gets
separately mangled, and then it is all joined back together. This allows
for fun stuff like (.foo? (Foo)), and even more contrived examples.
Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
The hy2py tool has been very useful for me, but most of the time, it's
only a part of its output that one is interested in. The whole output,
with source code, AST and python code together is one big monstrosity.
So instead of printing all that, lets have a few handy command-line
options to control which part gets printed.
By default, only the generated python source is, as that's what the name
of the tool implies.
Also, don't run it. That's what hy is for.
Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
There's no reason why one would need to choose between --spy and -i, so
pass down options.spy to run_icommand, and then to HyREPL, so we can
have both.
Signed-off-by: Gergely Nagy <algernon@balabit.hu>
* hy/core/language.hy:
-Added a simple coll? function that checks whether the given argument
is an iterable and not a string,
- Also replaced the check in `flatten` by coll?
* tests/native_tests/core.hy: Tests updated for checking coll?
