Although the documentation claimed that `read/recursive` produces
a plaeholder, that seems to be a leftover from a much older
reader (before `make-reader-graph`). Fix the new `read/recursive`
to be like the old one, and update the documentation.
Thanks to Alex Knauth for tracking down the unnecessary change
in reader behavior.
Related to #2099
Compared to v6.12, `map` & co. already provide better checking in
reporting an error when a keyword-requiring function is provided
with empty lists, but repair the error message to talk about
required keywords instead of just by-position arity.
Thanks to Philip McGrath for reporting the problem.
Related to #2099
If `local-expand` with a 'module-begin context introduces a macro
definition, but the definition is dropped while a non-macro definition
is later introduced, then make sure references go to the non-macro
definition.
This change also addresses a related scenario, where a
`local-expand`-discovered macro definition is not dropped, but it is
given an extra scope --- which amounts to the same thing from the
expander's perspective.
When a module body is expanded with `local-expand`, then submodules
can remain declared even if the submodule is discarded in the final
expansion. Since that's the way it has always been, leave it that way.
But also guard against a way of generating an import cycle via those
leftover declarations.
The `identifier-prune-lexical-context` operation doesn't really
work out with scope sets, and it was effectively disabled when
we switched the old expander to scope sets.
the fact that blame object equality now works right and
adding context to a blame object doesn't produce an equal?
blame object
also it appears that blame-add-unknown-context is not actually
being called so lets just get rid of that functionality
(but preserve reasonable backwards compatibility in
case someone is actually calling that function or
supplying #f to blame-add-context)
And the interning of blame objects was not intended to be
in 0b3f4b627e, so get rid of it here
closesracket/typed-racket#722
This ensures macro-introduction scopes don’t unintentionally end up on
lifted pieces of syntax, which causes problems for Check Syntax, since
it affects the syntax-original?-ness of the require spec.
Allow `syntax-local-make-definition-context` in places where the
created scope is not accumulated for stripping from `quote-syntax`.
Refine the docs to clarify those situtations.
A test for the repair exposed a problem with use-site scopes
and `quote-syntax`, so fix that, too.
Closes#2062
When `local-expand` is used for a 'module-begin context, use a fresh
binding -> definition-unreadable-symbol table for the nested
expansion. That way, the table used for the main expansion is
unchanged, and re-expanding or evaluating the expanded module will
arrive at the same unreadable symbols as the initial expansion.
The report and example are from Alexis.
The old implementation turns a single optional argument into two
arguments: the optional value and a boolean to indicate whether the
optional value is supplied.
The new expansion uses `unsafe-undefined` in place of not-supplied
arguments, in the general case. If the default-value expression is
simple enough, however, it is copied to call sites that would
otherwise supply `unsafe-undefined`. In the common case where the
default value is `#f`, for example, no run-time test is needed in the
core implementation function to check whether the default is supplied,
because a `#f` will be filled in for callers.
The performance improvement is tiny to non-existent for realistic
programs, but the simpler and reduced generated code may help in the
long run.
