6 Reading "info.ss" Files

(require setup/getinfo)

The setup/getinfo library provides functions for accessing fields in "info.ss" files.

(get-info collection-names)   →   (or/c  (symbol? [(-> any)] . -> . any)  false/c)

collection-names : (listof string?)

Accepts a list of strings naming a collection or sub-collection, and calls get-info/full with the full path corresponding to the named collection.

(get-info/full path)   →   (or/c  (symbol? [(-> any)] . -> . any)  false/c)

path : path?

Accepts a path to a directory. It returns #f if there is no "info.ss" file in the directory. If the "info.ss" file has the wrong shape (i.e., not a module using setup/infotab or (lib "infotab.ss" "setup")), or if the "info.ss" file fails to load, then an exception is raised.

Otherwise, get-info/full returns an info procedure of one or two arguments. The first argument to the info procedure is always a symbolic name, and the result is the value of the name in the "info.ss" file, if the name is defined. The optional second argument, thunk, is a procedure that takes no arguments to be called when the name is not defined; the result of the info procedure is the result of the thunk in that case. If the name is not defined and no thunk is provided, then an exception is raised.

(find-relevant-directories syms [mode]) → (listof path?)

syms : (listof symbol?)

mode : (symbols 'preferred 'all-available) = 'preferred

Returns a list of paths identifying installed directories (i.e., collections and installed PLaneT packages) whose "info.ss" file defines one or more of the given symbols. The result is based on a cache that is computed by setup-plt and stored in the "info-domain" sub-directory of each collection directory (as determined by the PLT_COLLECTION_PATHS environment variable, etc.) and the file "cache.ss" in the user add-on directory.

The result is in a canonical order (sorted lexicographically by directory name), and the paths it returns are suitable for providing to get-info/full.

If mode is specified, it must be either 'preferred (the default) or 'all-available. If mode is 'all-available, find-relevant-collections returns all installed directories whose info files contain the specified symbols – for instance, all installed PLaneT packages will be searched if 'all-available is specified. If mode is 'preferred, then only a subset of “preferred” packages will be searched, and in particular only the directory containing the most recent version of any PLaneT package will be returned.

No matter what mode is specified, if more than one collection has the same name, find-relevant-directories will only search the one that occurs first in the PLT_COLLECTION_PATHS environment variable.

(reset-relevant-directories-state!) → void?

Resets the cache used by find-relevant-directories.