Return, as a monadic value, a one-argument procedure that, given a node of TYPE, returns its edges. NODES is taken to be the sinks of the global graph.

Return, as a monadic value, a one-argument procedure that, given a node of TYPE, returns its back edges. NODES is taken to be the sinks of the global graph.

Return the list of nodes directly or indirectly connected to NODES according to the NODE-EDGES procedure. NODE-EDGES must be a one-argument procedure that, given a node, returns its list of direct dependents; it is typically returned by 'node-edges' or 'node-back-edges'.

Compute the hash of FILE with ALGORITHM.

Symbolic links are only dereferenced if RECURSIVE? is false. Directories are only supported if RECURSIVE? is #true or 'auto'. The executable bit is only recorded if RECURSIVE? is #true. If FILE is a symbolic link, it is only followed if RECURSIVE? is false.

For regular files, there are two different hashes when the executable hash isn't recorded: the regular hash and the nar hash. In most situations, the regular hash is desired and setting RECURSIVE? to 'auto' does the right thing for both regular files and directories.

This procedure must only be used under controlled circumstances; the detection of symbolic links in FILE is racy.

When FILE is a directory, the procedure SELECT? called as (SELECT? FILE STAT) decides which files to include. By default, version control files are excluded. To include everything, SELECT? can be set to (const #true).

Return a two-argument procedure that returns true when version-control metadata directories such as '.git' is found in DIRECTORY.

Return true if FILE matches a version control system from the list VCSES-DIRECTORIES.

This procedure evaluates to a predicate that reports back whether a given file - stat combination is part of the files tracked by Mercurial.

Return the file-name for packages using hg-download.

Return the version string for packages using hg-download.

Return a fixed-output derivation that fetches REF, a <hg-reference> object. The output is expected to have recursive hash HASH of type HASH-ALGO (a symbol). Use NAME as the file name, or a generic name if #f.

Like 'http-fetch', return an input port, but cache its contents in ~/.cache/guix. The cache remains valid for TTL seconds.

Call WRITE-CACHE with the HTTP input port and the cache output port to write the data to cache. Call CACHE-MISS with URI just before fetching data from URI.

HEADERS is an alist of extra HTTP headers, to which cache-related headers are added automatically as appropriate.

TIMEOUT specifies the timeout in seconds for connection establishment.

Write information about redirects to LOG-PORT.