Skip calling the domain projection in that case and, if all of the
arguments are any/c then also skip putting the contract continuation mark
This appears to give about a 20% speed up on this program:
#lang racket/base
(require racket/contract/base)
(define f
(contract
(-> any/c integer?)
(λ (x) 1)
'pos 'neg))
(time
(for ([x (in-range 4000000)])
(f 1)))
The recently added fast path for property-only chaperones did not
propagate the original object in the case that the property-only
chaperone wraps a `chaperone-procedure*` chaprerone.
Merge to v6.4
Fix `procedure-specialize` for a procedure that refers to a
syntax-object literal. A syntax-object literal becomes part of the
procedure closure, but in a special way that nomrally allows syntax
objects to be loaded on demand. For now, specialization counts as
a demand of the syntax object.
Merge to v6.4
When a procedure created by `unsafe-{chaperone,impersonate}-procedure`
is given the wrong number of arguments, the original procedure's name
should be used in the error message.
During inlining, the type information gathered in
code that was inside the lambda is copied to the outer
context. But the coordinates of the type information
were shifted in the wrong direction, so the type was
assigned to the wrong variable.
This bug is difficult to trigger, so the test is convoluted.
Merge to v6.4
Add 'module-body-inside-context, 'module-body-outside-context, and
'module-body-context-simple? properties to the expansion of a
`module` form. These properties expose scopes that are used by
`module->namespace` and taht appear in marshaled bytecode.
The expression in a `define-runtime-path` form is used in
both a run-time context and a compile-time context. The
latter is used for `raco exe`. In a cross-build context,
you might need to load OpenSSL support for Linux (say)
at build time while generating executables that refer to
Windows (say) OpenSSL support. In that case, `#:runtime?-id`
lets you choose between `(cross-system-type)` and
`(system-type)`.
Merge to v6.4
In particular, instead of going directly back to the chaperone, handle
the case where the function doesn't accept keyword arguments with a
less expensive fallback.
The less expensive fallback uses a case-lambda wrapper (wrapped inside
a make-keyword-procedure) to close over the neg-party and avoid the
chaperone creation. With this commit, the program below gets about 3x
faster, and is only about 20% slower than the version that replaces
the "(let ([f f]) ...)" with its body
#lang racket/base
(module m racket/base
(require racket/contract/base)
(provide (contract-out [f (-> integer? integer?)]))
(define (f x) x))
(require 'm)
(collect-garbage)
(time (for ([x (in-range 5000000)]) (let ([f f]) (f 1))))
Thanks, @samth!
OS X's libssl is deprecated, and it doesn't work with SSL connections
that need SNI. We'll distribute out own libssl builds for OS X via a
package, but we need a native implementation that works well enough to
get that package.
The 'secure protocol symbol is just a shorthand for
`(ssl-secure-client-context)`, but it helps highlight
that the default 'auto isn't secure, and having a plain
symbol smooths the connection to native Win32 and OS X
implementations of SSL.
The repair involves making `raco exe` detect a sub-submodule
whose name is `declare-preserve-for-embedding` as an indication
that a submodule should be carried along with its enclosing module.
Normally, `define-runtime-module-path-index` would do that, but
the submodule for `place` is created with `syntax-local-lift-module`,
and the point of `syntax-local-lift-module` is to work in a
nested experssion context where definitions cannot be lifted
to the enclosing module.
Made the hash-set chaperones essentially forward the hash chaperone
operations, but now explain them all in terms of set-based operations
in the docs.
Also adjusted value-blame and has-blame? to support late-neg projections
The issue is what happens when the actual function has other arities.
For example, if the function were (λ (x [y 1]) y) then it is not okay
to simply check if procedure-arity-includes? of 1 is true (what the
code used to do) because then when the function is applied to 2
arguments, the call won't fail like it should. It is possible to check
and reject functions that don't have exactly the right arity, but if
the contract were (-> string? any), then the function would have been
allowed and only when the extra argument is supplied would the error
occur. So, this commit makes it so that (-> any/c any) is like
(-> string? any), but with the optimization that if the procedure
accepts only one argument, then no wrapper is created.
This is a backwards incompatible change because it used to be the
case that (flat-contract? (-> any)) returned #t and it now returns #f.
When a module defines <name-1> and doesn't export it, but when
the module imports <name-2> and re-exports that refers to another
module's definition of <name-1>, then <name-1> wasn't properly
registered as an unexported binding.
Most of the implementation change is just a clean-up of an
unnecessary traversal from before the addition of a `count`
field in each hash table.
Also, add `#:skip-filtered-directory?` to `find-files`.
Less significantly, adjust `pathlist-closure` to be consistent in the
way that it includes a separator at the end of a directory path.
Although `procedure-specialize` should be useful in places where
inlining does not apply, allowing inlining and related optimizations
through it, anyway.
- use chaperone-hash-set for set/c when the contract allows only hash-sets
- add a #:lazy flag to allow explicit choice of when to use laziness
(but have a backwards-compatible default that, roughly, eschews laziness
only when the resulting contract would be flat)
Specifically, remove reliance on procedure-closure-contents-eq? to
tell when a pending check is stronger in favor of usint
contract-stronger?
Also, tighten up the specification of contract-stronger? to require
that any contract is stronger than itself
With this commit, this program gets about 10% slower:
#lang racket/base
(require racket/contract/base)
(define f
(contract
(-> any/c integer?)
(λ (x) (if (zero? x)
0
(f (- x 1))))
'pos 'neg))
(time (f 2000000))
becuase the checking is doing work more explicitly now but because the
checking in more general, it identifies the redundant checking in this
program
#lang racket/base
(require racket/contract/base)
(define f
(contract
(-> any/c integer?)
(contract
(-> any/c integer?)
(λ (x) (if (zero? x)
0
(f (- x 1))))
'pos 'neg)
'pos 'neg))
(time (f 200000))
which makes it run about 13x faster than it did before
I'm not sure if this is a win overall, since the checking can be more
significant in the case of "near misses". For example, with this
program, where neither the new nor the old checking detects the
redundancy is about 40% slower after this commit than it was before:
#lang racket/base
(require racket/contract/base)
(define f
(contract
(-> any/c (<=/c 0))
(contract
(-> any/c (>=/c 0))
(λ (x) (if (zero? x)
0
(f (- x 1))))
'pos 'neg)
'pos 'neg))
(time (f 50000))
(The redundancy isn't detected here because the contract system only
looks at the first pending contract check.)
Overall, despite the fact that it slows down some programs and speeds
up others, my main thought is that it is worth doing because it
eliminates a (painful) reliance on procedure-closure-contents-eq? that
inhibits other approaches to optimizing these contracts we might try.
The `procedure-specialize` function is the identity function, but it
provides a hint to the JIT to compile the body of a closure
specifically for the values in the closure (as opposed to compiling
the body generically for all closure instances).
This hint is useful to the contract system, where a predicate
is coerced to a projection with
(lambda (p?)
(procedure-specialize
(lambda (v)
(if (p? v)
v
....))))
Specializing the projection to a given `p?` allows primitive
predicates to be JIT-inlined in the projection's body.
in particular, when there is a recursive contract, then we check only
some part of the first-order checks and see if that was enough to
distinguish the branches. if it was, we don't continue and otherwise we do
A value that starts "1", "y", or "Y" enabled incremental mode
permanently (any value was allowed formerly), while a value that
starts "0", "n", or "N" causes incremental-mode requests to be
ignored.
When custom categories are used in older versions, raco setup will
report a warning, but the documentation will still appear under the
Miscellaneous section. Thus, this is a backwards compatible
implementation of the idea.
Port `examples`, `interactions`, etc., to use the new `examples`
form of `scribble/examples`. The main intended effect is to ensure
that errors are produced by examples only as specifically
indicated.
- uniformly remove the extra layers of calls to unknown functions for
chapereone-of? checks that make sure that chaperone contracts are
well-behaved (put those checks only in contracts that are created
outside racket/contract)
- clean up and simplify how missing projection functions are created
(val-first vs late-neg vs the regular ones)
- add some logging to more accurately tell when late-neg projections
aren't being used
- port the contract combinator that ->m uses to use late-neg
- port the </c combinator to use late-neg
Really, just improve when majors GCs are forced to trigger
further finalizations. This improvement makes `(collect-garbage)`
followed by `(collect-garbage 'incremental)` move more
reliably into incremental mode.
Although calling `(collect-garbage 'incremental)` in a program with
a periodic task is the best way to request incremental collection, it's
handy for some experiments to have an environment variable that turns
it on permanently.
This change also makes incremental-mode minor collections log as "mIn"
instead of "min", and it changes the first field of the logged
`gc-info` structure to be a mode symbol instead of a boolean.
The bug was an induced failure in the http server, to test retry
support, triggered another run of half of the synchronization
protocol, leading to a stuck state.
The strategy of converting a bignum to a flonum by converting on word
boundaries can lose one bit of precision. (If the use of a word
boundary causes a single bit to get rounded away, but the first bit of
the next word is non-zero, then the rounding might have been down when
it should have been up.)
Avoid the problem by aligning relative to the high bit, instead.
Fix even basic readind when extflonums are not supported, but
also fix reading extflonums with large exponents (related to
the other recent changes to number parsing).
Allow a more dynamic (than `impersonator-prop:application-mark`)
determination of continuation marks and associated values to wrap the
call of an impersonated procedure.
When an internal-definition context is used with `local-expand`, the
any binding added to the context affect expansion, but the binding do
not appear in the expansion. As a result, Check Syntax was unable to
draw an arrow from the `s` use to its binding in
(class object%
(define-struct s ())
s)
The general solution is to add the internal-definition context's
bindings to the expansion as a 'disappeared-bindings property. The new
`internal-definitionc-context-track` function does that using a new
`internal-definition-context-binding-identifier` primitive.
In #956, @gus-massa warned that `syntax-local-infer-name` was changed
in a breaking way, but the implications were not clear. At a minimum,
identifiers need to be treated like symbols, so that `mzlib/contract`
name inference works right. I'm erroring more generally on the side
of keeping the old behavior for anything other than pair-based
trees.
Closes#1117.
Repairs 3eb2c20ad0, which used a scope-set comparison for
a table that maps scopes to propagation actions (add, remove,
or flip).
Closes#1113
Merge to v6.3
So now (-> any/c integer?) will avoid the chaperone wrapper when the
function is a struct predicate while simultaneously supporting the
"extra argument neg party" protocol
In `syntax-local-lift-require`, avoid scope adjustments intended
to deal with `require` forms that are compiled in one namespace
and evaluated in another.
When `or` has many subexpressions, the expansion generates a
sequence of deeply nested `let`s, where original and macro-introduced
forms are interleaved in a way that defeats a minimal
child-is-same-as-parent sharing of scope sets. Add a small
cache that's good enough to capture extra sharing and
dramatically lower memory use for an `or` that has 1000
subexpressions.
When an import is shadowed by another import or by a definition, don't
include it in the set of bindings in the resut of
`syntax-local-module-required-identifiers` or in the set that can be
exported by `all-from-out`.
Merge to v6.3
To make the API consistent for MSVC versus MinGW builds, make
a functional formerly required for embedding on 32-bit Windows
always available and required for all Windows variants.
Make the old-generation marking process incremental
on request, where `(collect-garbage 'incremental)`
makes a request.
Only the marking phase of an old-generation collection
is incremental, so far. In exchange for slower
minor collections and a larger heap, you get a major
collection pause time that is roughly halved. So, this
is a step forward, but not good enough for most purposes
that need incremental collection.
An incremental-mode request sticks until the next
major GC. The idea is that any program that could
benefit from incremental collection will have
some sort of periodic task where it can naturally
request incremental mode. (In particular, that
request belongs in the program, not in some external
flag to the runtime system.) Otherwise, the
system should revert to non-incremental mode, given
that incremental mode is slower overall and can
use much more memory --- usually within a factor of
two, but the factor can be much worse due to
fragmentation.
After some expansions, a expression with the syntax property 'inferred-name of
'x is converted to one with ('x . 'x), so it's not useful to get the name of a
procedure. So we simplify the syntax property 'inferred-name to handle
these cases.
Removing all original module context doesn't work, because it
doesn't distinguish between fragments of syntax that had the
"inside-edge" scope without the "outside-edge" scope.
Record the presence of the outside-edge scope by using the
root scope, and convert the root scope to the current namespace's
outside-edge scope on evaluation.
The bug could cause
#lang racket/base
(define x 'outer)
(define-syntax-rule (def-and-use-m given-x)
(begin
(define-syntax-rule (m)
(let ()
(define given-x 'inner)
x))
(m)))
(def-and-use-m x)
to produce 'inner when it should produce 'outer.
Thanks to Brian Mastenbrook for pointing the problem and
providing examples.
On my machine, the sync path was sometimes triggered for "htdp-ptr".
(I'm not sure why; progress toward determinsitic bytecode might
be relevant.) Adjust the trigger for sync mode to check that the
needed "provides.sxref" file exists.
In the common case of a minor GC without a generation 1/2
or a major GC without compaction, a single pass suffices
to both mark and update references.
This change reduces overall GC time by 10%-25% on typical
programs.
The GC supported allocation for an array of objects where
the first one provides a tag, but at this point it was
used only in some corners. Change those corner and simplify
the GC by removing support for arrays of tagged objects.
The main corner to clean up is in the handling of a macro-expansion
observer and inferred names. Move those into the compile-time
environment. It's possible that name inference has been
broken by the changes, but in addition to passing the tests,
the generated bytecode for the base collections is exactly the
same as before the change.
First bug:
When the optimize converts
(let-values ([(X ...) (values M ...)])
....)
to
(let ([X M] ...)
....)
it incorrectly attached a virtual timestamp to each "[X M]" binding
that corresponds to the timestamp after the whole `(values M ...)`.
The solution is to approximate tracking the timestamp for invidual
expressions.
Second bug:
The compiler could reorder a continuation-capturing expression past
an allocation.
The solution is to track allocations with a new virtual clock.
Make `eval-syntax`, `compile-syntax`, and `expand-syntax` more
consistent (with intent and each other) by not installing a fallback
automatically. In particular, a fallback is not installed for a
`module` form, so that different ways of expanding a `module` form
produce consistent results (e.g., for ambiguous bindings).
p ..k matches exactly k repetitions of p, but its documented
behavior is to match "k or more" repetitions. This fix implements
the documented behavior.
Fixes bug number 15122.
Also, strengthen the checking that `#:permissive?` (off by default)
performs for `untar` and `untgz` to disallow a link whose target is an
absolute path or has an up-directory element.
The symbol is used as the "who" field in the error message.
Also fix lazy-require of runtime-report.rkt in residual.rkt; don't
load until syntax-parse actually needs to produce an error report.
(Previously was loaded to create handler whenever syntax-parse code ran.)
Test added in 8ee717520f was broken, because it used
`(current-milliseconds)` instead of `(current-ienxact-milliseconds)`
to construct an argument to`alarm-evt`'
Using the GitHub API for GitHub sources can run afoul of API
limits. Since we now support the Git protocol generall, use
that for GitHub sources, too.
Set the `PLT_USE_GITHUB_API` environment variable to use the
GitHub API, instead.
Refine the changes in 16c198805b so that `(define id ... id ... )` at
the top level compiles more consistently when `id` is an identifier
whose lexical context does not include `#%top`.
When `compile` is used on a top-level definition, do not
create a binding in the current namespace, but arrange for
a suitable binding to be in place for the target namespace.
Closes#1036
This repair adjusts the bug fix of commit 769ad3e98. That older commit
ensured that `sync/enable-break` doesn't both break and accept a
channel message or semaphore wait. But it effectively disables those
actions if the break is continued.
Instead of (partially!) ending the `sync` get out of semaphore
and channel queues so that no event can be selected during
the break, and then get back in line if the break is continued.
When a path is made relative for marshaling to bytecode, record
a list of byte strings in stead of a platform-specific relative
path.
For syntax-object source locations, convert any non-relative path to a
string that shows just the last couple of path elements preceded by
".../". This conversion avoids embedding absolute paths in bytecode,
but at the cost of some information. A more complete and consistent
solution would invove using a module-path index instead of a path, but
that would be a big change at several layers.
Make room in the bytecode format for source locations and 'paren-shape
property values for syntax objects. Saving source locations increases
bytecode size by about 10% on average.
Also, convert the internal representation of syntax properties to
use immutable hash tables, instead of lists.
The `prop:expansion-contexts` property can control the expansion
of a rename transformer in much the same that conditionals on
`(syntax-local-context)` can control the expansion of other
transformers.
These avoid one layer of currying and are more efficient, getting
about a 1.3x speed up on this program:
#lang racket/base
(module server racket/base
(require racket/contract/base)
(provide
(contract-out
[f (-> integer? boolean? char? void?)]))
(define (f i b c) (void)))
(require (submod "." server))
(time
(for ([x (in-range 10000000)])
(f 1 #t #\x)))
All places uses the same accounting bit for objects
that are in the shared space. Each place also flips
the bit value it wants on each accounting, so if two
places are accounting at the same time with opposite
bit values and can reach the same objects, they can
interefere. It's even possible for them to race
through cycles and cause each other to loop forever.
Add a lock to ensure that there's only one bit value
in play for the shared space at any given time. A
place must stall if other places are busy with memory
accounting and an opposite bit value.
While a place message is received by a thread but not yet
deserialized, if the message contains references to objects in the
shared space, and if a "master" GC happens (which crosses all places),
make sure that the references in the still-serialized message are
traversed.
Adjust installation tools to support cross-installation (i.e.,
installation for a platform other than the current one) as triggered
by "system.rktd" in "lib" having different information than the
running Racket executable.
Support PNG-encoded icons in ".ico" files and executables.
For executables, instead of supporting only new icons that match the
sizes and encodings of existing icons in an executable, support
arbitrary replacement icons in an executable.
The improved funcitonality relies on a new library (currently
private) for general updates to a Windows executable's
resources.
A `module-suffixes` entry in a collection's "info.rkt" adds a
file suffix that is meant to be recognized globally (i.e., in
all collections) by all Racket tools.
The new fields are reported by `compiler/module-suffix` library, which
is (so far) used by `raco setup`.
Note that if package A includes files with a suffix that is registered
by package B, then A should have a dependency on B, but `raco setup`
cannot currently detect that such a dependency is needed. That
dependency is likely to happen, anyway, since package A is likely
using libraries form package B.
The `from` string argument is converted to a regexp and cached. When `from` is
a mutable string this can cause wrong results in the following calls
to string-replace. So the string is first converted to an immutable string to
be used as the key for the cache.
When `place` expands, the body of the `place` form is placed into a
`(module* place-body-<n> #f ....)` submodule.
The `place` form previously placed its body in a lifted function,
where the function's exported name was based on
`(current-inexact-milliseconds)`. The generated submodules have
deterministic names, so that compilation is deterministic, and
submodule names don't collide (unlike exported function names) when
multiple `place`-using module are imported into some other module.
Also, using a submodule avoids the problem that the clock doesn't
change fast enough on Windows.
Changes:
- Allow unit contracts to import and export the same signature.
- Add "invoke" contracts that will wrap the result of invoking a unit contract,
no wrapping occurs when a body contract is not specified
- Improve error messages
- Support for init-depend clauses in unit contracts.
- Fix documentation to refelct the above
- Overhaul of unit related tests
Handling init-depend clauses in unit contracts is a rather large and somewhat
non-backwards-compatible change to unit contracts. Unit contracts must now
specify at least as many initialization dependencies as the unit value being
contracted, but may include more. These new dependencies are now actually
specified in the unit wrapper so that they will be checked by compound-unit
expressions.
This commit also adds more information to the first-order-check
error messages. If a unit imports tagged signatures, previously the errror
message did not specify which tag was missing from the unit contract. Now
the tag is printed along with the signature name.
Documentation has been edited to reflect the changes to unit/c contracts
made by this commit.
Additionally this commit overhauls all tests for units and unit contracts.
Test cases now actually check that expected error messages are triggered when
checking contract, syntax, and runtime errors. Test forms now expand into uses
of rackunit's check-exn form so only test failures are reported and all tests in
a file are run on every run of the test file.
Progress toward making the bytecode compiler deterministic, so that a
fresh `make base` always produces exactly the same bytecode from the
same sources. Most changes involve avoiding hash-table order
dependencies and adjusting scope identity. The namespace used to load
a reader extension is also better defined. Plus many other little
changes.
The identity of a scope that is unmarshaled from a bytecode file now
incorporates the hash of the file, and the relative order of scopes is
preserved in a bytecode file. This combination allows compilation to
start with modules that loaded and compiled in different orders
(including delayed loading of bytecode fragments within one file).
Formerly, a reader extension triggered by `#lang` or `#reader` was
loaded in whatever namespace happens to be current. That's
unpredictable and can pollute a module build at the level of bytecode.
To help make builds deterministic, reader extensions are now loaded in
a root namespace of the current namespace.
Deterministic compilation in general relies on deterministic macros.
The two most common ways for a macro to be non-deterministic are by
using `gensym` (use `generate-temporaries`, instead) and by using an
unsorted hash-table traversal (don't do that).
At this point, bytecode generation is unlikely to be completely
deterministic, since I uncovered non-determinism mostly by iterating
attempts over the base collections. For now, the intent is not to
provide guarantees outside of the compilation of the base collections
--- but "more deterministic" is likely to be useful in the short run,
and we can improve further in the long run.
When a module is currently installed as bytecode, but without
corresponding source and without a "info.rkt" specification that
bytecode should be preserved without source, then `raco pkg` should
not count that module bytecode as a conflict (since `raco setup`
will remove it).
Nested splicing forms would lead to an "ambigious binding" error
when the nested forms bind the same name, such as in
(splicing-let ([a 1])
(splicing-let ([a 2])
(define x a)))
The problem is that splicing is implemented by adding a scope to
everything in the form's body, but removing it back off the
identifiers of a definition (so the `x` above ends up with no new
scopes). Meanwhile, a splicing form expands to a set of definitions,
where the locally bound identifier keeps the extra scope (unlike
definitions from the body). A local identifier for a nested splicing
form would then keep the inner scope but lose the outer scope, while
a local identifier from the outer splicing form would keep the outer
scope but no have the inner one --- leading to ambiguity.
The solution in this commit is to annotate a local identifier for a
splicing form with a property that says "intended to be local", so the
nested definition will keep the scope for the outer splicing form as
well as the inner one. It's not clear that this is the right approach,
but it's the best idea I have for now.
Although `eval-syntax` is not supposed to add the current namespace's
"outer edge" scope, it must add the "inner edge" scope to be consistent
with adding the inner edge to every intermediate expansion (as in
other definition contexts).
In addition, `eval`, `eval-syntax`, `expand`, and `expand-syntax`
did not cooperate properly with `local-expand` on the inner edge.
1st is a small grammatical mistake
2nd is in a section about ->* yet mistakenly -> is referred to
3rd is about recontract-out yet contract-out is mentioned instead
4th clarifies return value for value-contract
5th replaces free-identifier? with free-identifier=?
Genereating a use-site scope, instead of a macro-introduction scope,
prevents the scope's presense from triggering a #f result from
`syntax-original?`.
This change mostly reverts 1465ff25fc, which turned out to be a hassle
because it created more cyclic structure.
A simpler strategy is to allow a phase-specific scope to be detached
(perhaps temporarily, due to on-demand loading of bytecode) from its
group; when that's possible, the scope is not reachable from a place
where it can be moved to other syntax objects, so it's ok to be
detached. Debugging output needs to handle that gracefully, though.
Also, in case of broken bytecode, fix up a detached scope if it
does end up in an unexpected place.
Formerly, compiling a definition in one namespace and evaluating it in
another would cause the definition to take place in the original
namespace --- unless the compiled code is marshaled to a byte string
and back. Adjust the "linking" process to redirect the variable
definition and any references to the new namespace. (This is a change
relative to the compiler with the old macro expander.)
Also, repair a compiled `require` form along similar lines. (This is
*not* a change relative to the compiler with the old macro expander;
the mismatch is part of the motivation for changing `define`
handling.)
Part of the expansion to handle contracts confused internal and
external names of signature elements. The new macro expander is less
tolerant of the mistake.
Add the current definition context's scope to any expression that is
produced by macro expansion before trying to expand again, in case the
expansion needs to refer to a definition introduced by a previous
expansion.
Previously, the scope was added before any expansion and after any
expansion, but that misses intermediate points.
The old expander had this bug, too (some of the new tests fail there),
but it showed up less often and was sometimes considered correct, for
various reasons.
The revised implementation of `define-generics` for the new macro
expander wasn't right, because the macro attached to `<gen>/c` for a
given `<gen>` used a macro-introduced reference to the generic to
match up method names with the generic's methods.
The `eval-syntax` function (which is used by other functions, such as
loading a module) should not install fallback-binding scopes from
the current namespace.
When `(let ([x ...]) (let ([y x]) ... y ... y ...))` turns into
`(let ([x ...]) ... x ... x ...)`, make sure that `x` is not
still marked as single-use. Incorrect marking as single-use could
cause the optimizer to inline too much, for example.
Thanks to Gustavo for tracking down the problem.
Previously all the predicates recognized only non-#f things, so ´not´ can be
added to the list of disjoint predicates. But many of the parts of the code
relied on the non-#f property and had to be modified.
In (if (eq? x <pred?-expr>) <tbranch> <fbranch>) infer that the type of
x is pred? in the tbranch.
Also, reduce (eq? x y) => #f when the types are different.
The optimizer reduces the variables with a known type to #t in a Boolean context.
But some predicates imply that the variable has a definite values, so they can be
reduced in a non-Boolean context too.
For example, in (lambda (x) (if (null? x) x 0))) reduce the last x ==> null.
This fixes the bug twice:
* Don't reduce mutable variables with a type to #t in a Boolean context.
* Don't record the type of mutable variables when a predicate is
checked in a test condition.
While reducing some ignored constructors, the optimizer may wrap the arguments
<expr> in (values <expr>) to ensure that it's a single value non-cm expression.
This avoids the unnecessary nesting of (values (values <expr>)).
Similarly, add the cases for begin and begin0 to single_valued_noncm_expression
When a package "p" is clone-linked and the repo for "p" changes to be
a multi-package repository (e.g., with "p-lib", "p-doc", and "p"), a
`raco update` would get confused. Unofrtunately, a plain `raco pkg
update p` can't work in that case, because the clone link would still
be a pathless repo URL; the repairs make `raco pkg update --lookup
--clone ..../p` work as is should.
Related: fix inference of package names in the early check for whether
a package is installed.
While `#:in-original-place? #t` provides one way to serialize
foreign calls, it acts as a single lock and requires expensive
context switches. Using an explicit lock can be more efficient
for serializing calls across different places.
For example, running "plot.scrbl" takes 70 seconds on my machine
in the original place and using `#:lock-name` in any place,
while it took 162 seconds in a non-main place with Cairo+Pango
serialization via `#:in-original-place? #t`.
Internally, the named lock combines compare-and-swap with a
place channel. That strategy gives good performance in the case
of no contention, and it cooperates properly with the Racket
scheduler where there is contention.
The optimizer was able to use the type information gained outside
the let's to reduce expressions inside the lets. For example, in
(lambda (z) (car z) (let ([o (random)]) (pair? z)))
it reduces (pair? z) ==> #t.
This enable the propagation in the other direction so in
(lambda (z) (let ([o (random)]) (car z)) (pair? z))
it reduces (pair? z) ==> #t too.
- Coalesce repeated use of the same predicate.
- Fix scoring of Exact patterns, and scoring generally.
- Use `OrderedAnd` where needed.
- Guarantee that `and` patterns match in order.
- Thread bound variable information properly in GSeq compilation.
- Warn when variables are used non-linearly with `...`
(making this behave properly was not backwards compatible).
Closes#952, which now runs in <1ms and make it a test case.
Also add margin note about `?` patterns and multiple calls.
When `local-require` is used in a non-phase-0 position and it is
`expand`ed (as opposed to compiled directly), then the generated
`#%require` form had the wrong binding phase.
Merge to v6.2
In many use cases the length of the vector is fixed and know,
so we are sure that make-vector will not raise an error and
we can recognize these expressions as omittable and drop
them when the result is ignored.
The result of some procedures is a vector, but they are not omittable
because they may rise an error. With the recent changes of the
predicate reduction these cases are correctly handled.
Adds a sealing and unsealing function to attach (or detach)
seals onto a class via impersonator properties. Since these
properties override, they do not accumulate wrappers.
Calling seal multiple times will still accumulate multiple seal
values inside the property.
A sealed class cannot be instantiated and a subclass may not
add class members that match any of the sealed names in its
sealed parent.
These functions are intended for use by TR's `sealing->/c`
contract, but are parameterized over checking functions and
could be used for other purposes.
An empty string provided to `raco pkg config --set catalogs` would
trigger an error previously. Instead, turn it into a `#f` in the
configuration file, which is replaced by the default search sequence.
The optimizer checks the type of the argument of some unary procedures and
uses the gathered information to replace them by the unsafe version, reduce
predicates and detect type errors. This extends the checks to more procedures
that have no unsafe version and procedures that have more than one argument.
Use the given readtable more consistently to parse
delimiters in the top-level form. This change particularly
addresses problems with trying to restore the original
`(` when parsing a hash table, but allowing nested
forms to still use a different `(` mapping.
When determing whether expressions can be reordered, a reference to a
module-defined variable was considered unreorderable when it is
known to have a value and no further mutation, but the value isn't
constant across all runs.
