Section "paths"

To allow for the circumstances of a browser, we do not provide a search path of multiple loca-tions and/or multiple file extensions. Rather the mechanism is such that only one resource, the Prolog flag system_url, is probed. Dogelog player can also load native libraries written in the host programming language of the target platform:

library(N): (file spec)
The file spec addresses the Prolog text library N.
foreign(N): (file spec)
The file spec addresses the native library N.

Plain file names in include/1 or ensure_loaded/1 are resolved against the parent Prolog text. Otherwise, plain file names are resolved against the Prolog flag base_url. The resolution result can be inspected via the predicate absolute_file_name/2, although it is not necessary to call this predicate before using file systems operations.

The following file path predicates are provided:

file_property(S, P):
The predicate succeeds with the properties of the file S that unify with P. The following file properties are support:

type(T): The type T of the file, possible values “regular”, “directory” and “other”.
absolute_path(Q): The resolved and normalized path Q for the file.
last_modified(L): The last modified date in milliseconds of the file.

 set_file_property(S, P):
The predicate assigns the property P to the file F. Currently supports the file property last_modified/1 for file system paths.
absolute_file_name(F, G):
absolute_file_name(F, G, L):
The predicate succeeds in G with the absolute file name of F. If F is already an absolute file name, then F is returned unchanged, otherwise the F is resolved against the base file path. The ternary predicate allows specifying absolute file options. The following absolute file options are supported:

relative_to(R): R is the base file path, default is the Prolog flag base_url.

is_absolute_file_name(F):
The predicate succeeds if F is an absolute file name. A file name is considered absolute if it starts with a file separator or if it contains a protocol separator before the first file separator or in itself.
file_directory_name(F, G):
The predicate succeeds in G with the directory name of the file name F. The trailing file separator is included in the directory name.
file_base_name(F, G):
The predicate succeeds in G with the base name of the file name F. File names with trailing file separator return empty base name.


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