module Make:
Constructs path handling module for string-like type and its operations given in S
.
Parameters: |
|
type
ustring
Type of strings used. In case of Path.OfRope
it is Rope.t
and in Path.OfString
module it is string
.
type
uchar
Type of characters. It corresponds to ustring
type.
module OperatorLift:sig
..end
Convenience operator for lifting primitive strings to ustring
type.
typet =
ustring list
A type for storing paths. It is reversed list of names. In case of absolute path, the last element of the list is empty string (Windows: empty or letter-colon; details below). Empty list represents empty relative path.
Examples: ["a";"b";"c"]
is c/b/a (relative path); ["d";"e";""]
stays for /e/d (absolute path).
All examples here and below are given for ustring
=string
case for clarity. To have the code working with other string types, one should prepend the !!
operator (BatPathGen.PathType.OperatorLift.(!!)
) to all string literals.
There are two infix operators provided to allow to write expressions in natural order. For example, to build a path using BatPathGen.PathType.Operators.(/:)
one can write:
base_dir/:"bar"
instead of "bar"::base_dir
However it may be sometimes inevitable to write components in reverse, for example:
let whose_readme = function "README"::app::"doc"::"share"::_ -> Some app | _ -> None
Windows: Windows absolute paths start with "\\" or with drive letter. Use following representation:
Path.root/:"."/:"pipe" = ["pipe";".";""]
for "\\.\pipe"["C:"]/:"foo" = ["foo";"C:"]
for "C:\foo"In principle the first type of paths has broader range of allowed characters, but this implementation applies more strict rules to both (BatPathGen.PathType.default_validator
).
val is_relative : t -> bool
val is_absolute : t -> bool
val root : t
Root of the filesystem ([""]
). It is minimal absolute path. Below it is called 'empty'. However it yields "/" or "\\" when converted to a string.
Windows: This path (root and nothing more) is meaningless, but for simplicity it is considered valid here. To create absolute path starting with drive letter, construct the list explicitly (as in ["C:"]/:"foo"
).
A path consisting of drive letter only is also called 'empty' here.
val append : t -> ustring -> t
Alternative name for BatPathGen.PathType.Operators.(/:)
val concat : t -> t -> t
Alternative name for BatPathGen.PathType.Operators.(//@)
module Operators:sig
..end
Infix operators for path construction.
module Infix:sig
..end
As other Operators modules in batteries are named "Infix" we provide Infix as well.
exception Malformed_path
val normalize_filepath : t -> t
Consumes single dots where possible, e.g.:
normalize ([".."]/:"foo"/:"."/:"bar"/:"sub1"/:".."/:"sub2") = [".."]/:"foo"/:"bar"/:"sub1"/:".."/:"sub2"
When a directory structure contains links, it can be not pefectly pure tree. Then meaing of the ".." symbol depends on the real nature of parent of what is denoted by the name that preceded the ".." symbol. This symbol cannot be resolved for a graph traversal case when dealing with abstract paths only.
Windows: If single dot is next to root, it is preserved.
val normalize_in_graph : t -> t
Another name for normalize_filepath
.
val normalize_in_tree : t -> t
Consumes single dots and applies double dots where possible, e.g.:
normalize ([".."]/:"foo"/:"."/:"bar"/:"sub1"/:".."/:"sub2") = [".."]/:"foo"/:"bar"/:"sub2"
This normalization is useful when dealing with paths that describe locations in a tree and the ".." symbol always points to the only parent of what precedes this symbol.
Windows: If single dot is next to root, it is preserved.
Malformed_path
when absolute path is given that contains double dots that would be applied to the root.val normalize : t -> t
Deprecated name for normalize_in_tree
val parent : t -> t
Returns parent path, i.e. immediate ancestor: parent (foo/:bar) = foo
Invalid_argument
if empty path (relative []
or absolute [""]
) is givenval belongs : t -> t -> bool
belongs base sub
is true
when sub
descends from base
, i.e. base
is a prefix of sub
. If base
=sub
the function returns true
. It is otherwise false
.
Both arguments must be absolute paths or both relative.
If both arguments have a root portion with drive letter and these letters are different, belongs base sub
returns false.
Invalid_argument
if exactly one of given arguments is absolute pathval relative_to_any : t -> t -> t
relative_to_any base sub
returns relative path rel
such that
normalize (base/:rel) = normalize sub
, i.e. common base is stripped and ".." are added if necessary.
Both arguments must be absolute paths or both relative.
This function normalizes base
and sub
before calculation of the relative path.
Windows: If base
and sub
are absolute, they must have the same root element: have the same drive letter or both starting with BatPathGen.PathType.root
(i.e. ""
is the last element of the list).
Exceptionally it is possible to get an absolute path as a result if drive letter is in sub
but not as a root element (e .g. base = root/:"bar"
and sub = root/:bar//@(["C:"]/:"foo"
).
Invalid_argument
if exactly one of given arguments is an absolute pathMalformed_path
if normalization fails (see BatPathGen.PathType.normalize
)relative_to_parent
may be sometimes more suitableexception Not_parent
val relative_to_parent : t -> t -> t
relative_to_parent parent sub
returns relative path rel
such that
(normalize parent)/:rel = normalize sub
. It is checked if sub
is really a descendant of parent
.
Both arguments must be absolute paths or both relative.
This function normalizes base
and sub
before calculation of the relative path.
Windows: Exceptionally it is possible to get an absolute path as a result if drive letter is in sub
but not as a root element (e .g. base = root/:"bar"
and sub = root/:bar//@(["C:"]/:"foo")
).
Not_parent
if sub
is not descendant of parent
Invalid_argument
if exactly one of given arguments is absolute pathMalformed_path
if normalization fails (see BatPathGen.PathType.normalize
)exception Illegal_char
Raised by BatPathGen.PathType.of_string
, BatPathGen.PathType.append
and BatPathGen.PathType.Operators.(/:)
when used validator finds illegal character.
typevalidator =
ustring -> bool
Validators should check if all characters of given string can be used in a name (path component). Return true if the name is valid. Return false if illegal character is found.
If a name should be rejected for some other reason, user defined validator may raise an exception.
val default_validator : validator Stdlib.ref
Forward slash and code zero are considered invalid.
Windows: Invalid characters are *?:\/<> and all with code <32. Exception: the function BatPathGen.PathType.of_string
doesn't use validator against drive letter with colon.
val to_ustring : t -> ustring
Convert to the chosen ustring
type. Empty relative path is converted to "." (single dot).
Windows: backslash is used as a separator and double backslash for root. If the path is only a drive letter (empty absolute path) trailing backslash is added (e.g. to_string ["C:"] = "C:\"
).
to_string
is likely to bo more useful
"val to_string : t -> string
Convert to type primitive string with UTF-8 content. The string is built in the same way as by to_ustring
function.
val of_string : ustring -> t
Parse path in a given string. Any number of consecutive separators collapse ("a//b" becomes "a/b"). Path.default_validator
is applied to each resulting name.
Windows: both slashes '\' and '/' are accepted as separators. Paths of the 'semi-relative' form "C:foo\bar" are not recognized. For example "C:" string is parsed as ["C:"]
which has different meaning (see BatPathGen.PathType.to_string
).
Illegal_char
when a character not allowed in paths is found.val s : t -> string
val p : ustring -> t
These functions do not accept empty paths, i.e. []
, [""]
or ["C:"]
.
val name : t -> ustring
Returns name of the object the pathname points to, i.e.
name (foo/:bar) = bar
Invalid_argument
if empty path (relative []
or absolute [""]
) is givenval map_name : (ustring -> ustring) ->
t -> t
map_name fu path
returns path
with the name replaced by fu (
BatPathGen.PathType.name
path)
.
Example: map_name (fun nn -> nn ^ ".backup") (["foo"]/:"bar") = ["foo"]/:"bar.backup"
BatPathGen.PathType.default_validator
is applied to new name.
Illegal_char
(raised by validator if any bad character is found)val ext : t -> ustring option
Returns extension of the name of the object the pathname points to. Examples:
ext ["aa.bb"] = Some "bb"
ext ["aa."] = Some ""
ext ["aa"] = None
ext [".hidden"] = Some "hidden"
(!)
Extension begins where the rightmost dot in the name is found. If the name ends with a dot, the extension is empty and Some ""
is returned. If there is no extension (no dot) the function returns None
.
Invalid_argument
if empty path (relative []
or absolute [""]
) is givenval map_ext : (ustring option -> ustring option) ->
t -> t
map_ext fu path
returns path
but with the name with extension given by fu (
BatPathGen.PathType.ext
path)
. If fu
returns Some _
, the original extension may be replaced (when Some ext
is passed to fu
) or new added (when fu
gets None
). In case fu
returns None
, the extension is removed (if exists).
Illegal_char
(raised by validator if any bad character is found)Invalid_argument
if empty path (relative []
or absolute [""]
) is givenval name_core : t -> ustring
Returns part of the name to the left of rightmost dot. Returns empty string if the name starts with a dot.
Invalid_argument
if empty path (relative []
or absolute [""]
) is giventypecomponents =
t * ustring *
ustring option
A path
can be represented by the following triple:
(Path.parent path, Path.name_core path, Path.ext path)
val split : t -> components
Dissect the path to its components (parent path, core part of name and possibly an extension).
Resulting name_core
string can be empty. For example,
Path.split (Path.root/:"home"/:"user"/:".bashrc")
equals (Path.root/:"home"/:"user", "", Some "bashrc")
.
Invalid_argument
if empty path (relative []
or absolute [""]
) is givenval join : components -> t
Create a path from given components.
Illegal_char
(raised by validator on any bad character)val map : (components -> components) ->
t -> t
Map a path through a function that operates on separate components.
Illegal_char
(raised by validator on any bad character)Invalid_argument
if empty path (relative []
or absolute [""]
) is givenval drive_letter : t -> uchar option
Return drive letter of the given absolute path.
Windows: drive_letter abs
returns None
if abs
is simple absolute path (i.e. begins with a separator), otherwise the root element of abs
consists of a letter ch
with a colon - in this case Some ch
is returned.
Other systems: Returns None
on all absolute paths.
Invalid_argument
if relative path is given