For easier macro writing purposes, allow an empty (cond), that simply
returns nil. Closes#904.
Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
To mirror the behaviour of (setv), allow an empty (del) too: one that
shall return nil. Closes#905.
Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
To allow classes to have methods that match built-in names, yet, still
disallow them outside of defclass, keep an internal state whether
builtins are allowed in the current context.
By default, this is false. But defclass will set it to True when it
compiles its body, and set it back to the previous value when it's done
with that. We need to set back to the previous value to allow nested
defclasses to work properly.
This closes#783.
Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
Strip the \ufdd0 prefix from the keyword argument before turning it into
a string: the same representation the user entered looks better, and is
printable too, thus Python2 doesn't choke on it.
Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
Some valid-looking list comprehensions, such as (genexpr x []) can crash
Python 2.7. The AST we generate from these cannot be expressed in
Python, but were valid in Hy.
Added two guards to guard against this, so we raise an error instead of
crashing Python.
Closes#572, #591 and #634.
Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
Postfixing functions with a bang, like set!, get!, etc are relatively
common. However, those names are not valid in python, so in the name of
python interoperability, lets mangle them to set_bang and get_bang,
respectively.
Closes#536.
Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
When trying to setv a callable, raise an error instead of showing the
user an incredibly ugly backtrace. Closes#532.
Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
In case for doesn't get a body, raise the appropriate, descriptive error
instead of an IndexOutOfBounds one. Also updated the failing test case.
Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
defclass now has a new syntax:
(defclass Name [BaseList]
[property value
property value] ;; optional
(defn method [self]
self.property))
Anything after the optional property list (which will be translated to a
setv within the class context) will be added to the class body. This
allows one to have side effects and complex expressions within the class
definition.
As a side effect, defining methods is much more friendly now!
Closes#850.
Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
xor with more than two input parameters is not well defined and people
have different expectations on how it should behave. Avoid confusion by
sticking with two parameters only.
Added xor to complement and, or, not operators. Standard python
falsey/truthy semantics are followed. This implementation works for
two or more parameters.
The `with-decorator` special form is not the most ergonomic—this commit
introduces a new builtin `#@` reader macro that expands to an invocation
of `with-decorator`. To support this, `reader_macroexpand` is made to
also look in the default `None` namespace, in imitation of how
regular (non-reader) macros defined in hy.core are looked up. The
docstring of `hy.macros.reader` is also edited slightly for accuracy.
This in the matter of issue #856.
Much like how `can_compile` returns the compilation result, which some
tests make use of, it may be useful for for `cant_compile` to return the
exception object that it caught, for more specific assertions.
Python 3 supports keyword-only arguments as described in the immortal
PEP 3102. This commit implements keyword-only argument support for Hy
using a `&kwonly` lambda-list-keyword with semantics analogous how
`&optional` arguments are handled: `&kwonly` arguments are either a
symbol, in which case the keyword argument so named is mandatory, or a
two-element list, the first of which is the symbolic name of the keyword
argument and the second of which is its default value if not
supplied. If Hy is running under Python 2, attempting to use `&kwonly`
args will raise a HyTypeError.
This effort is with the aim of resolving #453.
Expressions can sometimes contain itertools.islice objects, which we can
only walk if we force them into a list. To do this, the walk function
has to be taught that collections that are not instances of list should
be forced into a list.
Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
Python 3.5's PEP 448 ("Additional Unpacking Generalizations") allows the
iterable- and dictionary- unpacking operators to be used more than once;
the implementation (see https://hg.python.org/cpython/rev/a65f685ba8c0)
gets rid of the optional `starargs` and `kwargs` arguments to `ast.Call`
and `ast.ClassDef`, instead using `ast.Starred` and `ast.keyword`
objects inside of the normal `args` and `keywords` lists,
respectively. This commit allows Hy's `apply` to work correctly with
this revised AST when running under Python 3.5.
As reported in issue #748, there was a bug in which passing a lambda
as the value of a :keyword argument would fail—
$ hy --spy
hy 0.10.1 using CPython(default) 3.4.0 on Linux
=> (sorted (range 10) :key (fn [x] (- x)))
from hy.core.language import range
sorted(range(10), key=_hy_anon_fn_1)
Traceback (most recent call last):
File "<input>", line 1, in <module>
NameError: name '_hy_anon_fn_1' is not defined
The function call would appear in the generated AST without being
preceded by the appropriate function definition corresponding to the
anonymous function argument value in the Hy source, causing either a
NameError (as in the example above), or erroneous reuse of whatever
function was already pointed to by the `_hy_anon_fn_` name referenced
in the list of keywords passed to `ast.Call`.
This commit aims to fix the problem by handling it in same way that
the expression/statement gap is bridged many other places in the
compiler, by adding the compiled value of the keyword argument to the
Result object being built during `_compile_collect`, with the
understanding that any Python statements implied by the argument value
will be appropriately preserved therein.
Python 3.5 will have a new commercial-at infix operator with the magic
methods __matmul__, __rmatmul__, and __imatmul__, unused as yet in the
standard library, but intended to represent matrix multiplication in
numerical code; see PEP 465 (https://www.python.org/dev/peps/pep-0465/)
for details. This commit (developed against Python 3.5 alpha 3) brings
support for this operator to Hy when running under Python 3.5 (or,
hypothetically as yet, greater). For Hy under Python <= 3.4, attempting
to use `@` in function-call position currently results in a NameError;
this commit does not change that behavior.
This is intended to resolve#668.
jcrocholl/pep8 (used by flake8, used in Hy's continuous integration
builds) introduced an imports-at-top-of-file check in 1.6.0 and a
line-breaks-around-binary-operators check in 1.6.2. This commit makes
nonfunctional changes to bring the Hy codebase in compliance with this
tool, fixing #764.
This code is heavily, *heavily* based off of Guillermo Vaya
(willyfrog)'s work... instead of defining its own keyword arg though, it
uses the "standard" :kwarg type, which is the main difference from
willyfrog's original branch.
Included tests and some documentation in the tutorial.
Also documented "apply" separately as an example of reproducing
*args and **kwargs.
When (fn) or (defn) does not get an arglist as first/second parameter,
emit a more descriptive error message, rather than an ugly traceback.
Fixes#716.
Reported-by: Joakim Tall
Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
Our MetaImporter was being inserted at the end of sys.meta_path.
For Python prior to 3.3, this was fine since sys.meta_path
was empty by default. As of the completion of PEP 302 in Py3.3 and
later, there are several importers registered by default. One of
these was trying (and failing) to import simple Hy modules,
resulting in a failure to import anything inside __init__.hy.
This change simply inserts the Hy-specific importer at the front
of the list.
This was noted in issue #620 (great catch @algernon)
