alice
library
manual.
signature URL
structure Url : URL
This structure provides functions for parsing URLs, extracting URL constituents, constructing URLs from constituents and resolving relative URLs. Absolute and relative URLs are supported. URL parsing conforms to RFCs 1738 and 1808 with one exception: We allow a URL to contain a single-letter device constituent before the path, which is a mostly-conservative common extension. Device letters enable the embedding of Windows-style path and file names within the set of URLs.
See also: OS.Path, HASHABLE, ORDERED
import structure Url from "x-alice:/lib/system/Url"
import signature URL from "x-alice:/lib/system/URL-sig"
signature URL =
sig
eqtype url
type t = url
type scheme = string option
type authority = string option
type device = char option
type path = string list
type query = string option
type fragment = string option
exception Malformed
exception NotLocal
val empty : url
val setScheme : url * scheme -> url
val setAuthority : url * authority -> url
val setDevice : url * device -> url
val makeAbsolutePath : url -> url
val makeRelativePath : url -> url
val setPath : url * path -> url
val setQuery : url * query -> url
val setFragment : url * fragment -> url
val getScheme : url -> scheme
val getAuthority : url -> authority
val getDevice : url -> device
val isAbsolutePath : url -> bool
val getPath : url -> path
val getQuery : url -> query
val getFragment : url -> fragment
val fromString : string -> url
val toString : url -> string
val toStringRaw : url -> string
val toLocalFile : url -> string
val isAbsolute : url -> bool
val resolve : url -> url -> url
val equal : url * url -> bool
val compare : url * url -> order
val hash : url -> int
end
The type of parsed URLs. Values of this type represent absolute as well as relative URLs. The equivalence test using = is reliable for absolute URLs only. URL values are always normalized.
The types of the respective URL constituents. Option types are used to indicate the presence or absence of optional indiviual constituents. Device letters are always normalized to their lower-case equivalent, that is, are always in the range #"a" ... #"z" if present. The absent path is equivalent to the empty path, represented by nil. Path constituents can contain empty strings. The last element of a path constituent being the empty string represents the absence of a file name constituent (that is, the string representation of the path constituent ends in a slash). Constituents use no encoding except for the query, which has to encode #"=" and #"&". The only URL constituent for which there is no explicit type defined is the flag whether the path constituent is absolute or relative, that is, whether its string representation starts with a slash or not.
indicates that a string is not a well-formed URL in string representation, or that a URL constituent has no well-formed string representation.
raised by toLocalFile to indicate that a URL does not have a local file name equivalent.
represents the empty URL, which has all constituents absent resp. empty. Its string representation is the empty string.
return a URL with the corresponding constituent replaced. If x is SOME _, this causes the constituent to be present in the result, if it is NONE, the constituent is absent in the result. Raise Malformed if x is not a valid value for the constituent.
return a URL equivalent to url except that its path constituent is absolute resp. relative.
return a URL with the corresponding constituent replaced. If x is SOME _, this causes the constituent to be present in the result, if it is NONE, the constituent is absent in the result.
return the corresponding constituents of url. For optional constituents, return SOME _ if the constituent is present, NONE otherwise.
returns true if the path constituent of url represents an absolute path, that is, a path whose string representation starts with a slash, false otherwise.
parses s as a URL in string representation, raising Malformed if it is not well-formed. The resulting URL is normalized and returned.
converts url into its string representation. Characters within constituents are encoded as required by RFC 1738.
converts url into its string representation, without encoding any characters. Should only be used to construct messages and if the URL is known not to contain any control characters.
if possible, converts url to a local file name, else raises the NotLocal exception. This operation
returns true if url represents an absolute URL, false otherwise. An URL is absolute if at least one of scheme or device is present or if the path constituent is an absolute path or starts with ".", ".." or the character #"~".
resolves relUrl with respect to baseUrl and returns the resulting URL. baseUrl should be an absolute URL, although this is not required.
returns true if url1 and url2 represent the same URL, false otherwise. Is identical to
url1 = url2
is equivalent to
String.compare (toString url1, toString url2)
returns a hash value for url.