* with-decorator: Allow a `setv` form as the form to be decorated
This feature is of dubious value by itself, but it's necessary to allow `defn` to create a lambda instead of a `def`.
* Make `fn` work the same as `lambda`
That is, allow it to generate a `lambda` instead of a `def` statement if the function body is just an expression.
I've removed two uses of with_decorator in hy.compiler because they'd require adding another case to HyASTCompiler.compile_decorate_expression and they have no ultimate effect, anyway.
In a few tests, I've added a meaningless statement in `fn` bodies to force generation of a `def`.
I've removed `test_fn_compiler_empty_function` rather than rewrite it because it seems like a pain to maintain and not very useful.
* Remove `lambda`, now that `fn` does the same thing
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.
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
