Auto-promotion now occurs in only two cases: when we start the compiler and when we expand a macro. It's fully recursive so even a non-model nested in a model will be promoted.
This change fixes some regressions induced by the stricter type checks of the pattern-matching compiler.
It's rarely useful, because it catches all exceptions, but it doesn't let you do anything other than return `None`. You can still get the same effect with `(except [])`.
HyKeywords are no longer an instances of string with a particular
prefix, but a completely separate object.
This means keywords no longer trip isinstance str checks, adding a
little bit of type safety to the compiler.
It also means that HyKeywords evaluate to themselves.
Closes#1352
Python Class AST expects a body which is a list of ast.Expr. Force
every entry to be stored as a statement. This means we'll preserve
print statements.
Python also doesn't construct docstrings in classes by setting a
__doc__ attribute, it does it by inspecting the first ast.Expr node of
the class. But this means we can remove the special handler for it.
This means that a HySymbol remembers its original name. That is, `a-b` and `a_b` are different symbols although `(setv a-b 1)` and `(setv a_b 1)` set the same variable (namely, `a_b`).
Most of the edits in this commit are to switch underscores to hyphens in places where mangling hasn't happened yet.
I removed some lexer tests since the lexer no longer does any mangling.
This removes a lot of hy-reprs that were hard-coded into the hy-repr function itself. It also allows you to add a hy-repr for an existing class without monkey-patching the class.
