The `if` form now supports elif clauses.
It works like `cond` but without the implicit `do`.
The old `if` is now `if*`
variadic lif now supports "ellif" clauses.
Update if-no-waste compiler to use `if*` properly.
(Sometimes one character is all it takes.)
document if
reword truthiness
Comparison operators such as =, !=, <, >, <=, >= should support a
one-arity version too, and return true in those cases (except for !=,
which returns false).
This closes#949.
Reported-by: Matthew Egan Odendahl
Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
This changes with syntax from (with [[x (expr)] (expr)] ...) to (with
[x (expr) (expr)] ...). Should have no ill side effects apart from the
syntax change.
Closes#852.
Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
This changes let to use a flat list of symbol-value pairs instead of a
vector of vectors. One side effect is that (let [[a 1] z]) is not
expressible now, and one will explicitly need to set a nil value for z,
such as: (let [a 1 z nil]).
Closes#713.
Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
apply now mangles strings and keywords according to the Hy mangling
rules (by using the same function, now imported from
hy.lex.parser). With this change, if the dict passed to apply has
keywords, strings or quoted symbols, they'll get mangled, to turn them
into proper keys.
This only works for the cases where the keys are directly in the apply
params. A previously deffed dict, or key through a variable will not be
mangled.
This closes#219.
Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
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>
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.
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>
Python has the keyword.iskeyword method we can leverage for Python
keywords, but we also need to address Hy builtins like 'get' or
'slice'.
And to make behavior compatible with Python 2 or 3, we also make
a special case to prevent assignment to False, True or None as
well as the Hy versions: false, true, null, and nil.
For non-Hy modules, we also check to make sure the symbol is not
part of the compiler. This allows shadow.hy to override "+" but
prevents general use from re-defn-ing 'get' or 'do'.
