These exception types are intended as a hook for a programming
environment to recommend packages that can provide a module that isn't
found (through an uncaught-exception handler). The new exceptions are
generated by the default module name resolver and defaultload
handler. In addition to the exceptions, there's a new
`prop:exn:missing-module' property and `exn:missing-module?', which is
what an environment should use to detect relevant exceptions.
There's also a new `current-module-path-for-load' parameter, which
just provides a commuincation path from the module name resolver to
the the load handler. The parameter is a relatively ugly piece of the
puzzle, but it's the best I could find to squash the new functionality
into the existing stack of handlers.
... when PWD is defined and when it refers to the same directory
as the result of getcwd().
A shell sets PWD before starting Racket to communicate a preferred
way of referring to the current directory, which may involve soft
links that are not reflected in getpwd().
Swap order of argument for `environment-variables-get'
and `environment-variables-set!', so that the environment
variables come first --- which follows the usual order.
This change means that the parameter isn't used to get
the default environment variables, but that seems ok; the
convenient interface is `getenv' and `putenv'.
On Windows, case-normalized environment variable names.
Also, change the implementation to use an immutable hash
internally.
By default, a sandbox gets a fresh environment variable set,
which means that it does not affect environment variables
outside the sandbox (which means that sandboxed code cannot
set the Racket process's OS-level environment variables).
Closes PR 13667
The `current-environment-variables' parameter determines the current
mutable "environment variable set". If that set is the initial one for
a Racket process, then using the set corresponds to working with OS
environment variables. Otherwise, it's really just a hash table that
is packaged up as OS environment variables if a subprocess is created.
The new environment-variable interface works in terms of bytes, instead
of assuming that environment variable names and values fit in a string
encoding.
The string-based `getenv' and `putenv' are still available as
convenience wrappers. The checking on environment-variable names
for those wrappers is a little tighter, preventing any attempt to use a
name that contains "=".
Added contract checking to arity=?, arity-includes?, and normalized-arity.
Removed contract checking from normalize-arity to make it a total predicate.
Updated documentation for normalize-arity to reflect this change.
Allow a thread to be GCed when it is blocked on a place
channel for reading and the place channel's write end
is inaccessible.
GC is limited to threads that do not participate in cycles
of such threads, where the otherwise unerachable threads
are blocked on place channels that are reachable among the
set of threads. In other words, the GC finds the greatest
fix point (as measured by the threads to retain) instead of
least fix point --- which isn't what you want, but finding
the least fix point seems to require significant extra GC
machinery across places.
This improvement was intended to solve the same problem as
commit 7b0608c, but that case seems to run into the limitation
on cycles.
Enable extflonums in a MSVC build by relying on a MinGW-built DLL,
"longdouble.dll". The DLL is loaded on startup. If the DLL isn't
available, then `extflonum-available?' reports #f.
Instead of setting the floating-point mode globally to extended
precision, the mode is changed only just before (and restored right
after) extflonum arithmetic operations.
* See comment about implementation issues.
* Removed the `list?' requirement on `takef' etc -- so it matches the
non-*f versions. (IMO, it'd be better to drop it from all of them.)
This also changes the output of `dropf' to `any/c'.
* Swapped the argument order so the predicate is last -- this makes it
uniform with the non-f* versions. (IMO, it'b be better to use the
popular order in all of them instead.)
* Includes tests, and also improved version of previous tests.
* Includes docs, and also fixes to previous docs (eg, drop* doesn't
return a fresh list).
