A.16.1 The Package Directories.Hierarchical_File_Names
The library package Directories.Hierarchical_File_Names
is an optional package providing operations for file name construction
and decomposition for targets with hierarchical file naming.
Static Semantics
If provided, the library
package Directories.Hierarchical_File_Names has the following declaration:
package Ada.Directories.Hierarchical_File_Names
is
function Is_Simple_Name (Name :
in String)
return Boolean;
function Is_Root_Directory_Name (Name :
in String)
return Boolean;
function Is_Parent_Directory_Name (Name :
in String)
return Boolean;
function Is_Current_Directory_Name (Name :
in String)
return Boolean;
function Is_Full_Name (Name :
in String)
return Boolean;
function Is_Relative_Name (Name :
in String)
return Boolean;
function Simple_Name (Name :
in String)
return String
renames Ada.Directories.Simple_Name;
function Containing_Directory (Name :
in String)
return String
renames Ada.Directories.Containing_Directory;
function Initial_Directory (Name :
in String)
return String;
function Relative_Name (Name :
in String)
return String;
function Compose (Directory :
in String := "";
Relative_Name :
in String;
Extension :
in String := "")
return String;
end Ada.Directories.Hierarchical_File_Names;
In addition to the operations provided in package
Directories.Hierarchical_File_Names, the operations in package Directories
can be used with hierarchical file names. In particular, functions Full_Name,
Base_Name, and Extension provide additional capabilities for hierarchical
file names.
function Is_Simple_Name (Name : in String) return Boolean;
Returns True if Name is a simple name, and returns
False otherwise.
function Is_Root_Directory_Name (Name : in String) return Boolean;
Returns True if Name is syntactically a root (a
directory that cannot be decomposed further), and returns False otherwise.
function Is_Parent_Directory_Name (Name : in String) return Boolean;
Returns True if Name can be used to indicate symbolically
the parent directory of any directory, and returns False otherwise.
function Is_Current_Directory_Name (Name : in String) return Boolean;
Returns True if Name can be used to indicate symbolically
the directory itself for any directory, and returns False otherwise.
function Is_Full_Name (Name : in String) return Boolean;
Returns True if the leftmost directory part of
Name is a root, and returns False otherwise.
function Is_Relative_Name (Name : in String) return Boolean;
Returns True if Name allows the identification
of an external file (including directories and special files) but is
not a full name, and returns False otherwise.
function Initial_Directory (Name : in String) return String;
Returns the leftmost directory part in Name. That
is, it returns a root directory name (for a full name), or one of a parent
directory name, a current directory name, or a simple name (for a relative
name). The exception Name_Error is propagated if the string given as
Name does not allow the identification of an external file (including
directories and special files).
function Relative_Name (Name : in String) return String;
Returns the entire file name except the Initial_Directory
portion. The exception Name_Error is propagated if the string given as
Name does not allow the identification of an external file (including
directories and special files), or if Name has a single part (this includes
if any of Is_Simple_Name, Is_Root_Directory_Name, Is_Parent_Directory_Name,
or Is_Current_Directory_Name are True).
function Compose (Directory : in String := "";
Relative_Name : in String;
Extension : in String := "") return String;
Returns the name of the external file with the
specified Directory, Relative_Name, and Extension. The exception Name_Error
is propagated if the string given as Directory is not the null string
and does not allow the identification of a directory, or if Is_Relative_Name
(Relative_Name) is False, or if the string given as Extension is not
the null string and is not a possible extension, or if Extension is not
the null string and Simple_Name (Relative_Name) is not a base name.
The result of Compose is a full name if Is_Full_Name
(Directory) is True; result is a relative name otherwise.
Implementation Advice
Directories.Hierarchical_File_Names should be provided
for systems with hierarchical file naming, and should not be provided
on other systems.
46 These operations operate on file names,
not external files. The files identified by these operations do not need
to exist. Name_Error is raised only as specified or if the file name
is malformed and cannot possibly identify a file. The result of these
operations depends only on their parameters.
47 Containing_Directory raises Use_Error
if Name does not have a containing directory, including when any of Is_Simple_Name,
Is_Root_Directory_Name, Is_Parent_Directory_Name, or Is_Current_Directory_Name
are True.
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