On this page:
2.1 Reading Module Source Code
2.2 Getting Module Compiled Code
exn: get-module-code
2.3 Resolving Module Paths to File Paths
2.4 Simplifying Module Paths
2.5 Inspecting Modules and Module Dependencies

2 Module-Processing Helpers

2.1 Reading Module Source Code

 (require syntax/modread)

(with-module-reading-parameterization thunk)  any
  thunk : (-> any)
Calls thunk with all reader parameters reset to their default values.

(check-module-form stx 
  (or/c syntax? false/c)
  stx : (or/c syntax? eof-object?)
  expected-module-sym : symbol?
  source-v : (or/c string? false/c)
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.

2.2 Getting Module Compiled Code

 (require syntax/modcode)

(get-module-code module-path-v    
  [#:sub-path compiled-subdir0    
  #:compile compile-proc0    
  #:extension-handler ext-proc0    
  #:choose choose-proc    
  #:notify notify-proc    
  #:src-reader read-syntax-proc])  any
  module-path-v : module-path?
  compiled-subdir0 : (and/c path-string? relative-path?)
   = "compiled"
  compiled-subdir : (and/c path-string? relative-path?)
   = compiled-subdir0
  compile-proc0 : (any/c . -> . any) = compile
  compile-proc : (any/c . -> . any) = compile-proc0
  ext-proc0 : (or/c false/c (path? boolean? . -> . any)) = #f
  ext-proc : (or/c false/c (path? boolean? . -> . any))
   = ext-proc0
  choose-proc : 
(path? path? path?
 . -> .
 (or/c (symbols 'src 'zo 'so) false/c))
   = (lambda (src zo so) #f)
  notify-proc : (any/c . -> . any) = void
  read-syntax-proc : (any/c input-port? . -> . syntax?)
   = read-syntax
Returns a compiled expression for the declaration of the module specified by module-path-v.

The compiled-subdir argument defaults to "compiled"; it specifies the sub-directory to search for a compiled version of the module.

The compile-proc argument defaults to compile. This procedure is used to compile module source if an already-compiled version is not available.

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 is 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 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 prefered 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).

A parameter whose value is used like open-input-file to read a module source or ".zo" file.

(struct exn:get-module-code exn (path)
  #:extra-constructor-name make-exn:get-module-code)
  path : path?
An exception structure type for exceptions raised by get-module-code.

2.3 Resolving Module Paths to File Paths

 (require syntax/modresolve)

(resolve-module-path module-path-v    
  rel-to-path-v)  path?
  module-path-v : module-path?
  rel-to-path-v : (or/c path-string? (-> any) false/c)
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.

(resolve-module-path-index module-path-index    
  rel-to-path-v)  path?
  module-path-index : module-path-index?
  rel-to-path-v : (or/c path-string? (-> any) false/c)
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.

2.4 Simplifying Module Paths

 (require syntax/modcollapse)

(collapse-module-path module-path-v 
  (or/c path? module-path?)
  module-path-v : module-path?
  rel-to-module-path-v : any/c
Returns a “simplified” module path by combining module-path-v with rel-to-module-path-v, where the latter must have the form '(lib ....) or a symbol, '(file <string>), '(planet ....), a path, 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; otherwise, the result is a module path in the sense of module-path?.

When the result is a 'lib or 'planet module path, it is normalized so that equivalent module paths are represented by equal? results.

(collapse-module-path-index module-path-index 
  (or/c path? module-path?)
  module-path-index : module-path-index?
  rel-to-module-path-v : any/c
Like collapse-module-path, 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.

2.5 Inspecting Modules and Module Dependencies

 (require syntax/moddep)

Re-exports syntax/modread, syntax/modcode, syntax/modcollapse, and syntax/modresolve, in addition to the following:

(show-import-tree module-path-v)  void?
  module-path-v : module-path?
A debugging aid that prints the import hierarchy starting from a given module path.