117 lines
5.1 KiB
TeX
117 lines
5.1 KiB
TeX
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\section{URL}
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%
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\begin{description}
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\item[Used files:] url.scm
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\item[Name of the package:] url
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\end{description}
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%
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\subsection{Overview}
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This modules contains procedures to parse and unparse URLs. Till now,
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only the parsing of http URLs is implemented.
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\subsection{Entry points}
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\defun{make-userhost}{user password host port}{userhost-record}
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\defunx{userhost?}{thing}{boolean}
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\defunx{userhost:user}{userhost-record}{value}
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\defunx{userhost:password}{userhost-record}{value}
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\defunx{userhost:host}{userhost-record}{value}
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\defunx{userhost:port}{userhost-record}{value}
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\defunx{set-userhost:user}{userhost-record new-value}{void}
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\defunx{set-userhost:password}{userhost-record new-value}{void}
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\defunx{set-userhost:host}{userhost-record new-value}{void}
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\defunx{set-userhost:port}{userhost-record new-value}{void}
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\begin{desc}
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\ex{make\=userhost} creates a new \ex{userhost} record. This record
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describes path-prefixes of the form
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\semvar{user}:\semvar{password}@\semvar{host}:\semvar{port}. These
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are frequently used as the initial prefix of URL's describing
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Internet resources. Each slot is a decoded string or \sharpf (yes,
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\semvar{port} is also a string).
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\ex{userhost?} is the corresponding predicate,
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\ex{userhost:\ob{}user}, \ex{userhost:\ob{}pass\ob{}word},
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\ex{userhost:\ob{}host} and \ex{userhost:\ob{}port} are the
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correspondig selectors and \ex{set\=userhost:\ob{}user},
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\ex{set\=userhost:\ob{}pass\ob{}word}, \ex{set\=userhost:\ob{}host}
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and \ex{set\=userhost:\ob{}port} the corresponding mutators. As you
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can store everything into the record fields, the selectors may
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return any type of value. However, under normal circumstances, only
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\str\ or \sharpf\ is returned.
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\end{desc}
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\defun{parse-userhost}{path default}{userhost-record}
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\begin{defundescx}{userhost->string}{userhost-record}{string}
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\ex{parse\=userhost} parses a URI path (a list representing a path,
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not a string!) into a userhost record. Default values are taken from
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the userhost record \semvar{default} except for the host. The values
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are unescaped and stored into a userhost record that is returned.
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\ex{fatal\=syntax\=error} is called, if the specified path has no
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initial to slashes (i.e., it starts with `//\ldots').
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\ex{userhost->string} just does the inverse job: it unparses
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\semvar{userhost-record} into a string. The elements of the record
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are escaped before the are put together.
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For details about escaping and unescaping see section ``Handle
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URIs'' at page \pageref{sec:uri}.
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\end{defundescx}
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\defun{make-http-url}{userhost path search frag-id}{http-url-record}
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\defunx{http-url?}{thing}{boolean}
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\defunx{http-url:userhost}{http-url}{value}
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\defunx{http-url:path}{http-url}{value}
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\defunx{http-url:search}{http-url}{value}
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\defunx{http-url:frag-id}{http-url}{value}
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\defunx{set-http-url:userhost}{http-url new-value}{void}
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\defunx{set-http-url:path}{http-url new-value}{void}
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\defunx{set-http-url:search}{http-url new-value}{void}
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\defunx{set-http-url:frag-id}{http-url new-value}{void}
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\begin{desc}
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\ex{make\=http\=url} creates a new \ex{httpd\=url} record.
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\semvar{userhost} is a record, containing the initial part of the
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address (like
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\ex{ano\ob{}ny\ob{}mous@\ob{}clark.\ob{}lcs.\ob{}mit.\ob{}edu:\ob{}80}).
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\semvar{path} contains the URL's path split at slashes, e.g.\
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\ex{"foo/\ob{}bar/\ob{}baz/"} becomes \ex{'("foo" "bar" "baz" "")}.
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These elements are in raw, unescaped format. To convert them back to
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a string, use \ex{(uri\=path\=list->path (map escape\=uri
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pathlist))}. \semvar{search} and \semvar{frag\=id} are the last
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two parts of the URL (see section \ref{sec:uri} on page
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\pageref{sec:uri} about parts of an URI).
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\ex{http\=url:userhost}, \ex{http\=url:path}, \ex{http\=url:search}
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and \ex{http\=url:frag\=id} are the corresponding selectors,
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\ex{set\=http\=url:userhost}, \ex{set\=http\=url:path},
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\ex{set\=http\=url:search} and \ex{set\=http\=url:frag\=id} the
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corresponding mutators. As you can store every type of value into
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the record fields, the selectors can return any type of value.
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However, \ex{http\=:userhost} usually returns a \ex{userhost}
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record, \ex{http\=:path} returns a list of \str{}s and
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\ex{http\=url:search} and \ex{http\=url:frag\=id} return both
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\str{}s.
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\end{desc}
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\defun{parse-http-url}{path search frag-id}{http-url-record}
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\begin{defundescx}{http-url->string}{http-url-record}{string}
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The URI parser (\ex{parse\=uri} in \ex{uri.\ob{}scm}) maps a string
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to four parts: \semvar{scheme}, \semvar{path}, \semvar{search} and
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\semvar{frag-id} (see section \ref{proc:parse-uri} at page
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\pageref{proc:parse-uri} for details). If \semvar{scheme} is
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``http'', then the other three parts can be passed to
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\ex{parse\=http\=url}, which parses them into a \ex{http\=url}
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record. All strings come back from the URI parser encoded.
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\semvar{search} and \var{frag\=id} are left that way; this parser
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decodes the path elements. The first two list elements of the path
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indicating the leading double-slash are omitted.
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\ex{http-url->string} just does the inverse job. It converts a
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\ex{http\=url} record into a \str.
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\end{defundescx}
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%%% Local Variables:
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%%% mode: latex
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%%% TeX-master: t
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%%% End:
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