Module Http.Path

The type for absolute URI paths represented as non-empty lists of percent-decoded path segments. The empty list denotes the absence of a path.

Path segments can be empty "". The root path / is represented by the list [""] and /a by ["a"], see more examples here.

WARNING. You should never concatenate these segments with a separator to get a file path because they may contain stray percent-decoded directory separators. Use the function Path.to_absolute_filepath to interpret paths as file paths.

undot_and_compress p removes "." and ".." according to the RFC 3986 algorithm and suppresses non-final empty "" segments.

strip_prefix ~prefix p removes the prefix path prefix from p. If prefix is not a strict prefix of p this is None. If prefix = p this is Some [""], the root path. If prefix ends with an empty segment, it matches any corresponding segment at that point (so that stripping /a/ from /a/b results in /b).

A few examples:

• strip_prefix [] _ = None
• strip_prefix _ [] -> None
• strip_prefix [""] (_ :: _ as l) = Some l
• strip_prefix [""; "a"] [""; "a"] = Some [""]
• strip_prefix [""; "a"] [""; "a"; ""] = Some [""]
• strip_prefix [""; "a"] [""; "a"; "b"] = Some ["b"]
• strip_prefix [""; "a"; ""] [""; "a"] = None
• strip_prefix [""; "a"; ""] [""; "a"; ""] = Some [""]
• strip_prefix [""; "a"; ""] [""; "a"; "b"] = Some ["b"]

concat p0 p1 concatenates p0 and p1. This drops a potential last empty segment from p0.

has_dir_seps s is true iff s contains a '/' or a '\\' character.

to_absolute_filepath p is an absolute file path for undot_and_compress p. Errors if any of the path segments contains a stray slash or backslash or if p is the empty list. The result always uses / as a directory separator regardless of the platform and is guaranteed to be free of any . or .. segments.

prefix_filepath ~prefix p prefixes p by prefix avoiding introducing empty segments. This function assumes / is the directory separator regardless of the platform.

filepath_ext p is the file extension of file path p. This function assumes / is the directory separator regardless of the platform.

encode p encodes an absolute-path for p as follows:

1. In each segment percent-encode any byte that is not unreserved, sub-delims, ':' or '@' to produce a valid URI segment.
2. Prepends each segment with a '/'.
3. Concatenate the result.

The empty list is special cased and yields "". This is for encoding HTTP paths, use to_undotted_filepath to convert paths to file paths.

Here are a few examples:

• encode [] = ""
• encode [""] = "/"
• encode [""; ""] = "//"
• encode ["a";"b";"c"] = "/a/b/c"
• encode ["a";"b";"";"c";] = "/a/b//c"
• encode ["a";"b";"c";""] = "/a/b/c/"
• encode ["a";"b";"c";" "] = "/a/b/c/%20"
• encode ["a";"b";"c";"";""] = "/a/b/c//"
• encode ["a"; "b/"; "c"] = "/a/b%2F/c"
• encode ["r\xC3\xC9volte"] = "/r%C3%C9volte"
• encode ["a"; "not%20"; "b"] = "/a/not%2520/b"

decode s decodes an absolute-path to its percent-decoded list of segments. By definition of absolute-path the list of segments is never empty.

Here are a few examples:

• decode "/" = Ok [""]
• decode "//" = Ok ["";""]
• decode "/a/b/c" = Ok ["a";"b";"c"]
• decode "/a/b//c" = Ok ["a";"b";"";"c"]
• decode "/a/b/c/" = Ok ["a";"b";"c";""]
• decode "/a/b/c/%20" = Ok ["a";"b";"c";" "]
• decode "/a/b//c//" = Ok ["a";"b";"";"c";"";""]
• decode "/a/b%2F/c" = Ok ["a"; "b/"; "c"]
• decode "/r%C3%C9volte" = Ok ["r\xC3\xC9volte"]
• decode "/a/not%2520/b" = Ok ["a"; "not%20"; "b"]
• decode "" = Error _
• decode "a/b/c" = Error _

pp is an unspecified formatter for paths.