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- Bundle Operations
- Bundle Database Operations
- Bundle Template Operations
- Thread Local Storage
- Bugs and Limitations
- Version history
A Chicken implementation of SRFI 29.
The addition of the escape code ~[n]@* to the SRFI 28 format is not part of this extension.
undefined-condition?[procedure] (undefined-condition? OBJECT) => boolean
Is the OBJECT an instance of the SRFI 29 undefined-condition.
A composite-property-condition of (exn srfi-29 undefined).
unbound-variable-condition?[procedure] (unbound-variable-condition? OBJECT) => boolean
Is the OBJECT an instance of the SRFI 29 unbound-variable-condition.
A composite-property-condition of (exn srfi-29 unbound).
current-language[parameter] (current-language [LANGUAGE])
Gets or sets the LANGUAGE symbol.
current-country[parameter] (current-country [COUNTRY])
Gets or sets the COUNTRY symbol.
current-locale-details[parameter] (current-locale-details [LOCALE-DETAILS])
Gets or sets the LOCALE-DETAILS list.
current-locale-format-function[parameter] (current-locale-format-function [FORMAT-PROCEDURE])
Gets or sets the FORMAT-PROCEDURE.
This procedure must at least have the signature of a SRFI 28 format procedure. The default is the Chicken extras#format procedure.
This is not a paramter but a variable. It is not thread-local.
When the current-locale is changed, (see the locale egg), the current-* parameters need not be set individually. This will update those parameters to the values in the new locale. (Reset as in set anew.)
- A BUNDLE-SPECIFIER is a list of symbols of the form (PACKAGE-NAME [LANGUAGE] [COUNTRY] [DETAILS...]).
- A BUNDLE-ALIST is an association-list over with key TEMPLATE-NAME & value TEMPLATE-VALUE. The association-list elements must be of the form (TEMPLATE-NAME . TEMPLATE-VALUE).
That is (cons 'template-example 'value-example) is legal, whereas (list 'template-example 'value-example) is not. The form (list 'template-example 'value-example) will have the value (list 'value-example), and not 'value-example, as expected.
- A TEMPLATE-NAME is something suitable as a key, such as a symbol or string, but can be any object with a readable printname.
- A TEMPLATE-VALUE maybe any object, but should have a readable printname.
declare-bundle![procedure] (declare-bundle! BUNDLE-SPECIFIER BUNDLE-ALIST)
Creates a bundle.
undeclare-bundle![procedure] (undeclare-bundle! BUNDLE-SPECIFIER)
Removes the bundle specified by BUNDLE-SPECIFIER from the active bundles.
Bundle Database Operations
SRFI 29 does not specify how bundles are stored. This extension uses the filesystem for the bundle database.
Bundles are stored in the system bundle directory, (make-pathname (repository-path) "srfi-29-bundles"), unless an ALTERNATE directory is specified.
Within a bundle directory the structure is (directory [LANGUAGE] [COUNTRY] [SCRIPT] [CODESET] [MODIFIER] PACKAGE-NAME).
store-bundle![procedure] (store-bundle! BUNDLE-SPECIFIER [ALTERNATE])
Stores the bundle using the write procedure.
load-bundle![procedure] (load-bundle! BUNDLE-SPECIFIER [ALTERNATE])
Loads the bundle using the read procedure.
load-best-available-bundle![procedure] (load-best-available-bundle! BUNDLE-SPECIFIER [ALTERNATE])
Attempts (load-bundle! BUNDLE-SPECIFIER [ALTERNATE]), from most to least specific.
remove-bundle![procedure] (remove-bundle! BUNDLE-SPECIFIER [ALTERNATE])
Removes the bundle specified by BUNDLE-SPECIFIER from the active bundles, and from the filesystem.
Will not remove the locale directory hierarchy created by (store-bundle!...).
remove-bundle-directory![procedure] (remove-bundle-directory! BUNDLE-SPECIFIER [ALTERNATE])
Removes the bundle directory hierarchy created by (store-bundle!...). Will only remove empty directories. Returns #t if operation succeeded, #f when a non-empty directory encountered.
Does not remove the bundle, if any, from the active bundles. A filesystem only operation.
This procedure should be used with caution.
declared-bundle-specifiers[procedure] (declared-bundle-specifiers) => list
Returns a list of all the declared BUNDLE-SPECIFIERs.
declared-bundle-templates[procedure] (declared-bundle-templates BUNDLE-SPECIFIER) => list
Returns an association-list of all the templates for the BUNDLE-SPECIFIER.
most-specific-bundle-specifier[procedure] (most-specific-bundle-specifier PACKAGE-NAME) => bundle-specifier
Returns the most specific bundle specifier for the current locale.
The current locale is composed of the (current-language), (current-country), and (current-locale-details).
Note that the most-specific-bundle-specifier may not be a declared bundle.
Bundle Template Operations
These routines will use the most specific declared bundle for the package PACKAGE-NAME in the current locale.
required-localized-template[procedure] (required-localized-template PACKAGE-NAME TEMPLATE-NAME) => *
Returns the object for the TEMPLATE-NAME in PACKAGE-NAME. Otherwise a undefined-condition exception is raised.
localized-template[procedure] (localized-template PACKAGE-NAME TEMPLATE-NAME [PACKAGE-NOT-FOUND [TEMPLATE-NOT-FOUND]]) => *
Returns the object for the TEMPLATE-NAME in PACKAGE-NAME. Otherwise the appropriate ...-NOT-FOUND value.
PACKAGE-NOT-FOUND and TEMPLATE-NOT-FOUND have default #t,
localized-template/default[procedure] (localized-template/default PACKAGE-NAME TEMPLATE-NAME [PACKAGE-NOT-FOUND [TEMPLATE-NOT-FOUND]]) => *
Returns (localized-template PACKAGE-NAME TEMPLATE-NAME PACKAGE-NOT-FOUND TEMPLATE-NOT-FOUND).
PACKAGE-NOT-FOUND and TEMPLATE-NOT-FOUND have default TEMPLATE-NAME.
Somewhat like the Posix 'gettext' routine.
make-localized-template[procedure] (make-localized-template PACKAGE-NAME) => (procedure (symbol #!optional * *) *)
Returns a localized-template-like procedure curried upon the PACKAGE-NAME.
make-localized-template/default[procedure] (make-localized-template/default PACKAGE-NAME) => (procedure (symbol #!optional * *) *)
Returns a localized-template/default-like procedure curried upon the PACKAGE-NAME.
make-required-localized-template[procedure] (make-required-localized-template PACKAGE-NAME) => (procedure (symbol) *)
Like make-localized-template but raises an undefined-condition exception should the package or template be missing.
localized-format[procedure] (localized-format PACKAGE-NAME TEMPLATE-NAME ARG0...) => string
Returns the formatted string using the (current-locale-format-function) and the format string (localized-template PACKAGE-NAME TEMPLATE-NAME) on the arguments ARG0....
When a localized-template is not found and the TEMPLATE-NAME is a string then it is used a the format-string.
A representation is always displayed, even when no template is found. Just not a localized one.
localized-template-set![procedure] (localized-template-set! PACKAGE-NAME TEMPLATE-NAME VALUE) => boolean
Creates or updates the VALUE for the TEMPLATE-NAME in PACKAGE-NAME and returns #t, when the package exists. Otherwise returns #f.
This can be used to extend the meaning of a package template at runtime. For example: caching the actual closure for a named procedure.
load-localized-compiled-code[procedure] (load-localized-compiled-code LIBRARY PACKAGE-NAME TEMPLATE-NAMES)
Loads a Scheme code library and replaces the toplevel variable references from the templates with the actual value. Each item package-name+template-name has a variable reference upon entry. Upon exit this is replaced with the variable value after load.
Every item package-name+template-name referenced must be defined. Otherwise a (exn srfi-29 undefined) exception if raised.
LIBRARY is an absolute pathname, relative pathname, or (unitname pathname). The corresponding load call is load-relative, load-relative, and load-library. (See Unit eval.)
TEMPLATE-NAMES is a list of template-name.
A variable-reference is a symbol or (symbol symbol). The later is a module import reference; this is a brittle feature as it relies upon knowledge of implementation details.
Note that only load-relative is used for a library pathname. Be sure to provide an absolute-pathname when a current-directory relative pathname is needed.
localized-templates[procedure] (localized-templates PACKAGE-NAME) => list
Returns an association-list of all the templates for the PACKAGE-NAME.
- undefined-condition Signaled for unknown bundle-specification, package, template.
- unbound-variable-condition Signaled for an unbound reference during localized code resolution.
- (exn type) Signaled for argument type errors.
- (exn) message = "invalid library load specificiation" arguments = LIBSPEC Signaled during localized code resolution for a bad library load name form.
Thread Local Storage
Just as the locale extension supports per thread locale information so does this extension support per thread bundles. However, localized information is probably accessed more frequently than locale information. So the support for per thread bundles is delayed until runtime. Setting the environment variable SRFI29_TLS to [Yy1] will activate the feature.
When active each thread may have a different bundle for a package; i.e. a user of [[SRFI 19|srfi-19] can have a different language in each thread.
- Possible race condition exists creating a bundle file or directory should another thread be performing the same action.
Just do not allow this to happen.
- The locale symbols must have a lowercase printname! As such they do not truly reflect ISO 639-1/2 & ISO 3166-1 standard names. This is a SRFI 29 restriction.
- (current-locale-details) is ill-defined by the SRFI 29 document. Which symbol means what? This implementation defines locale details as a 3 element list (SCRIPT CODESET MODIFIER) where the elements are symbols or #f.
- The SRFI 29 document uses the term country for what the locale extension knows as region.
Bugs and Limitations
- Currently there is no support for source-form code. Such is considered an even worse security-hole than loading compiled code. However, a possibility is use of the sandbox. Should there be sufficient interest this area can be explored.
- Added runtime support for package per thread. Removed deprecated identifiers.
- Added unbound-variable-condition?. Deprecated !localized-template & make-!localized-template in favor of required-localized-template & make-required-localized-template.
- Added undefined-condition?, !localized-template, make-localized-template, make-localized-template/default, load-localized-compiled-code. localized-template & localized-template/default now distinguish an undefined template from an undefined package.
- Fixs for bundle-specifier? and load-best-available-bundle!
- Intitial Chicken 4 release. Added introspection routines. Removed PORT parameter for localized-format.
Copyright (C) 2010 Kon Lovett. All rights reserved.
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