4 Module-Processing Helpers
4.1 Reading Module Source Code
Calls thunk with all reader parameters reset to their default
values.
Inspects
stx to check whether evaluating it will declare a
module—
at least if
module is bound in the top-level to
Racket’s
module. The syntax object
stx can contain a
compiled expression. Also,
stx can be an end-of-file, on the
grounds that
read-syntax can produce an end-of-file.
The expected-module-sym argument is currently ignored. In
previous versions, the module form stx was obliged to declare
a module who name matched expected-module-sym.
If stx can declare a module in an appropriate top-level, then
the check-module-form procedure returns a syntax object that
certainly will declare a module (adding explicit context to the
leading module if necessary) in any top-level. Otherwise, if
source-v is not #f, a suitable exception is raised
using the write form of the source in the message; if
source-v is #f, #f is returned.
If stx is eof or eof wrapped as a syntax object, then an
error is raised or #f is returned.
4.2 Getting Module Compiled Code
Returns a compiled expression for the declaration of the module
specified by path and submodule-path, where
submodule-path is empty for a root module or a list for a
submodule.
The compiled-subdir argument defaults to "compiled";
it specifies the sub-directory to search for a compiled version of the
module. The roots list specifies a compiled-file search path
in the same way as the current-compiled-file-roots parameter.
The compile-proc argument defaults to compile. This
procedure is used to compile module source if an already-compiled
version is not available. If submodule-path is not '(),
then compile-proc must return a compiled module form.
The ext-proc argument defaults to #f. If it is not
#f, it must be a procedure of two arguments that is called
when a native-code version of path should be used. In that
case, the arguments to ext-proc are the path for the
extension, and a boolean indicating whether the extension is a _loader
file (#t) or not (#f).
The rkt-try-ss? argument defaults to #t. If it is not
#f, then if path ends in ".rkt", then the
corresponding file ending in ".ss" will be tried as well.
The choose-proc argument is a procedure that takes three
paths: a source path, a ".zo" file path, and an extension path
(for a non-_loader extension). Some of the paths may not
exist. The result should be either 'src, 'zo,
'so, or #f, indicating which variant should be used
or (in the case of #f) that the default choice should be
used.
The default choice is computed as follows: if a ".zo" version
of path is available and newer than path itself (in
one of the directories specified by compiled-subdir), then it
is used instead of the source. Native-code versions of path
are ignored, unless only a native-code non-_loader version exists
(i.e., path itself does not exist). A _loader extension
is selected a last resort.
If an extension is preferred or is the only file that exists, it is
supplied to ext-proc when ext-proc is #f,
or an exception is raised (to report that an extension file cannot be
used) when ext-proc is #f.
If notify-proc is supplied, it is called for the file
(source, ".zo" or extension) that is chosen.
If read-syntax-proc is provided, it is used to read the
module from a source file (but not from a bytecode file).
| (get-module-path | | path | | | | | #:submodule? submodule? | | | | [ | #:sub-path compiled-subdir0 | | | | | compiled-subdir | | | | | #:roots roots | | | | | #:choose choose-proc | | | | | #:rkt-try-ss? rkt-try-ss?]) | |
|
|
| path : path-string? |
| submodule? : boolean? |
|
|
|
| | choose-proc | | : | | | | | | | = | | (lambda (src zo so) #f) |
|
| rkt-try-ss? : boolean? = #t |
Produces two values. The first is the path of the latest source or compiled
file for the module specified by
path; this result is the path of the
file that
get-module-code would read to produce a compiled module
expression. The second value is
'src,
'zo, or
'so,
depending on whether the first value represents a Racket source file, a
compiled bytecode file, or a native library file.
The compiled-subdir, roots, choose-proc, and
rkt-try-ss? arguments are interpreted the same as by
get-module-code.
The submodule? argument represents whether the desired module is a
submodule of the one specified by path. When submodule? is
true, the result is never a 'so path, as native libraries cannot
provide submodules.
Constructs the path used to store compilation metadata for a source file stored
in the directory
path. The argument
roots specifies the
possible root directories to consider and to search for an existing file. The
sub-path arguments specify the subdirectories and filename of the
result relative to the chosen root. For example, the compiled
".zo"
file for
"/path/to/source.rkt" might be stored in
(get-metadata-path (build-path "/path/to") "compiled" "source_rkt.zo").
A parameter whose value is used like
open-input-file to read
a module source or
".zo" file.
4.3 Resolving Module Paths to File Paths
Resolves a module path to filename path. The module path is resolved
relative to rel-to-path-v if it is a path string (assumed to
be for a file), to the directory result of calling the thunk if it is
a thunk, or to the current directory otherwise.
Like
resolve-module-path but the input is a
module path index; in this case, the
rel-to-path-v
base is used where the module path index contains the “self” index.
If
module-path-index depends on the “self” module path
index, then an exception is raised unless
rel-to-path-v is a
path string.
See module-path-index-resolve.
Examples:
|
#<path:/home/scheme/pltbuild/racket/racket/collects/racket/main.rkt> |
|
#<path:/home/scheme/pltbuild/racket/build/user/6.6/pkgs/racket-doc/syntax/apple.rkt> |
|
'(submod #<path:banana.rkt> test) |
4.4 Simplifying Module Paths
Returns a “simplified” module path by combining
module-path-v with
rel-to-module-path-v, where the
latter must have one of the following forms: a
'(lib ....) or
symbol module path; a
'(file ....) module path; a
'(planet ....) module path; a
path;
'(quote symbol);
a
'(submod base symbol ...) module path
where
base would be allowed; or a thunk to generate one of those.
The result can be a path if module-path-v contains a path
element that is needed for the result, or if
rel-to-module-path-v is a non-string path that is needed for
the result. Similarly, the result can be 'submod wrapping a
path. Otherwise, the result is a module path (in the sense of
module-path?) that is not a plain filesystem path.
When the result is a 'lib or 'planet module path, it
is normalized so that equivalent module paths are represented by
equal? results. When the result is a 'submod module
path, it contains only symbols after the base module path, and the
base is normalized in the case of a 'lib or 'planet
base.
Examples:
Like
collapse-module-path when given two arguments, but the
input is a
module path index; in this case,
the
rel-to-module-path-v base is used where the module path
index contains the “self” index.
When given a single argument, collapse-module-path-index
returns a module path that is relative if the given module path index
is relative. The resulting module path is not necessarily normalized.
Changed in version 6.1.1.8 of package base: Added the one-argument variant for
collapsing a relative module path
index.
4.5 Inspecting Modules and Module Dependencies
Re-exports syntax/modread,
syntax/modcode, syntax/modcollapse,
and syntax/modresolve, in addition to the following:
A debugging aid that prints the import hierarchy starting from a given
module path.
4.6 Wrapping Module-Body Expressions
Added in version 6.0.0.1 of package base.
Constructs a function that is suitable for use as a
#%module-begin replacement, particularly to replace the
facet of #%module-begin that wraps each top-level
expression to print the expression’s result(s).
The function takes a syntax object and returns a syntax object using
module-begin-form. Assuming that module-begin-form
resembles #%plain-module-begin, each top-level expression
expr will be wrapped as (wrap-form expr), while
top-level declarations (such as define-values and
require forms) are left as-is. Expressions are detected after
macro expansion and begin splicing, and expansion is
interleaved with declaration processing as usual.