racket/collects/version/version.scrbl
2012-06-25 23:34:21 -06:00

133 lines
4.6 KiB
Racket

#lang scribble/doc
@(require scribble/manual
scribble/bnf
(for-label version/patchlevel
version/check
version/tool
version/utils
racket/base
racket/contract))
@(define (selflink s) (link s (tt s)))
@title{Version: Racket Version Checking}
The @filepath{version} collection contains several version-related
pieces that are used by Racket. See also @racket[version] from
@racketmodname[racket/base].
@; ----------------------------------------------------------------------
@section{Installed Patch Level}
@defmodule[version/patchlevel]
@defthing[patchlevel exact-nonnegative-integer?]{
Indicates the current installed patch level, which is normally zero,
but may be updated by patches to DrRacket.}
@; ----------------------------------------
@section{Checking Available Versions}
@defmodule[version/check]
@defproc[(check-version) (or/c symbol? list?)]{
Checks the currently available version on the PLT website
(@selflink["http://download.racket-lang.org"]) and returns a value that
indicates the current state of the curent installation:
@itemize[
@item{@racket[`ok] --- You're fine.}
@item{@racket[`(ok-but ,_version)] --- You have a fine stable
version, but note that there is a newer alpha version available
numbered @racket[_version].}
@item{@racket[`(newer ,_version)] --- You have an old
version. Please upgrade to @racket[_version].}
@item{@racket[`(newer ,_version ,_alpha)] --- You have an
old-but-stable version, please upgrade to @racket[_version]; you
may consider also the newer alpha version numbered
@racket[_alpha].}
@item{@racket[`(error ,_message)] --- An error occurred, and
@racket[_message] is a string that indicates the error.}
@item{@racket[`(error ,_message ,_additional-info)] --- An error
occurred; @racket[_message] is a string that indicates the
error, and @racket[_additional-info] is a string containing a
system error. The @racket[_additional-info] content is always
parenthesizes, so @racket[message] is a short error and
@racket[(string-append message " " additional-info)] is a
verbose one.}
]}
@; ----------------------------------------------------------------------
@section{DrRacket Version Tool}
@defmodule[version/tool]
The @racket[version/tool] library implements a DrRacket tool that
@itemize[
@item{makes the patchlevel display as a version @tt{p}@nonterm{N}
suffix in DrRacket (though the base verion reported by
@racket[(version)] is not changed);}
@item{if enabled by the user, periodically checks whether a
new Racket distribution is available for download.}
]
@; ----------------------------------------------------------------------
@section{Version Utilities}
@defmodule[version/utils]{
The @racketmodname[version/utils] library provides a few of convenient
utilities for dealing with version strings. Unless explicitly noted,
these functions do not handle legacy versions of Racket.}
@defproc[(valid-version? [str string?]) boolean?]{
Returns @racket[#t] if @racket[str] is a valid Racket version
string, @racket[#f] otherwise.}
@defproc[(version->list [str valid-version?])
(list integer? integer? integer? integer?)]{
Returns a list of four numbers that the given version string
represent. @racket[str] is assumed to be a valid version.}
@defproc[(version<? [str1 valid-version?] [str2 valid-version?]) boolean?]{
Returns @racket[#t] if @racket[str1] represents a version that is
strictly smaller than @racket[str2], @racket[#f] otherwise.
@racket[str1] and @racket[str2] are assumed to be valid versions.}
@defproc[(version<=? [str1 valid-version?] [str2 valid-version?]) boolean?]{
Returns @racket[#t] if @racket[str1] represents a version that is
smaller than or equal to @racket[str2], @racket[#f] otherwise.
@racket[str1] and @racket[str2] are assumed to be valid versions.}
@defproc[(alpha-version? [str valid-version?]) boolean?]{
Returns @racket[#t] if the version that @racket[str] represents is an
alpha version. @racket[str] is assumed to be a valid version.}
@defproc[(version->integer [str string?]) (or/c integer? false/c)]{
Converts the version string into an integer. For version
@racket["X.YY.ZZZ.WWW"], the result will be @racketvalfont{XYYZZZWWW}.
This function works also for legacy Racket versions, by
translating @racket["XYY.ZZZ"] to @racketvalfont{XYYZZZ000}. The
resulting integer can thefore be used to conveniently compare any two
(valid) version strings. If the version string is invalid the
resulting value is @racket[#f].
Note that this is the only function that deals with legacy version
strings.}