4.6 In-Source Documentation
The scribble/srcdoc and
scribble/extract libraries support writing
documentation withing the documentation code along with an export
contract, similar to using JavaDoc. With this approach, a
single contract specification is used both for the run-time contract
and the documentation of an exported binding.
The scribble/srcdoc library provides forms for
exporting a binding with associated documentation. The
scribble/extract library is used to pull
scribble/srcdoc-based documentation into a Scribble document
(perhaps for multiple libraries).
Although documentation is written with a library’s implementation when
using scribble/srcdoc, the documentation creates no
run-time overhead for the library. Similarly, typesetting the
documentation does not require running the library. The two phases
(run time versus documentation time) are kept separate in much the
same way that the module system keeps expansion-time code separate
from run-time code.
For an example use, see the "file" collection’s
"gif.rkt" source file and the corresponding extraction in
"scribblings/gif.scrbl". As that example illustrates,
prefixing the module declaration with
enables the @-reader, which is handy for writing documentation
expressions.
4.6.1 Source Annotations for Documentation
Like
provide or
provide/contract, but each
spec uses a
documentation transformer to describe
the exported identifier and its contract.
The currently supported documentation transformers are
proc-doc, proc-doc/names, parameter-doc,
and thing-doc.
Like
require, but for bindings that are needed at
documentation time (and documentation-expansion time, etc.) instead of
run time (and expansion time, etc.). A
require-doc form has
no effect on a normal use of the library; it affects only
documentation extraction.
Typically, a library that uses scribble/srcdoc
includes at least (require/doc scribble/base scribble/manual)
to get core Racket forms and basic Scribble functions to use in
documentation expressions.
| (proc-doc/names id contract ((arg-id ...) ((arg-id default-expr) ...)) desc-expr) |
| (proc-doc/names id case-contract ((arg-id ...) ((arg-id default-expr) ...)) desc-expr) |
| |
| contract | | = | | (-> arg ... result) | | | | | | | (->* (mandatory ...) (optional ...) result) | | | | | | | | mandatory | | = | | contract-expr | | | | | | | keyword contract-expr | | | | | | | | optional | | = | | contract-expr | | | | | | | keyword contract-expr | | | | | | | | case-contract | | = | | (case-> (-> arg ... result) ...) |
|
The arg-ids specify the names of arguments, which are not
normally written as part of a contract. They are combined with the
contract expression to generate the description of the binding in the
documentation via defproc. The (arg-id default-expr)
pairs specify the names and default values of the optional arguments.
The desc-expr is a documentation-time expression that
produces prose to describe the exported binding—that is, the last
part of the generated defproc, so the description can refer
to the arg-ids using racket.
The normal requires of the enclosing library are effectively
converted into for-label requires when generating
documentation, so that identifiers in the contracts are
linked to their corresponding documentation. Similarly, any binding
that is available in the run-time phase of of the enclosing library
can be referenced in documentation prose using the racket
form.
| (proc-doc id contract desc-expr) |
| |
| contract | | = | | (-> result) | | | | | | | (->d (arg ...) () (values [id result] ...)) | | | | | | | (->d (arg ...) () #:pre-cond expression (values [id result] ...)) | | | | | | | (->d (arg ...) () [id result]) | | | | | | | (->d (arg ...) () #:pre-cond expression [id result]) | | | | | | | (->d (arg ...) () #:rest id rest [id result]) |
|
Like
proc-doc, but supporting contract forms that embed
argument names. Only a subset of
->d forms are currently
supported.
Like
proc-doc, but for an export of an arbitrary value.
Like
proc-doc, but for exporting a parameter.
4.6.2 Extracting Documentation from Source
Expands to a sequence of documentation forms extracted from
module-path, which is expected to be a module that uses
scribble/srcdoc.
Similar to
include-extracted, but the documentation is
packaged and exported as
exported, instead of left
inline.
Use this form in combination with
include-previously-extracted when documentation from a single
source is to be split and typeset among multiple documentation
locations. The provide-extracted form extracts the
documentation once, and then include-previously-extracted
form extracts documentation for specific bindings as needed.