factor/library/httpd/url-encoding.factor

! :folding=indent:collapseFolds=1:

! $Id$
!
! Copyright (C) 2004 Slava Pestov.
! 
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! modification, are permitted provided that the following conditions are met:
! 
! 1. Redistributions of source code must retain the above copyright notice,
!    this list of conditions and the following disclaimer.
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! 2. Redistributions in binary form must reproduce the above copyright notice,
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IN: url-encoding
USE: combinators
USE: kernel
USE: logic
USE: format
USE: math
USE: parser
USE: stack
USE: strings
USE: unparser

: url-encode ( str -- str )
    [
        dup url-quotable? [ "%" swap >hex 2 digits cat2 ] unless
    ] str-map ;

: url-decode-hex ( index str -- )
    2dup str-length 2 - >= [
        2drop
    ] [
        ! Note that hex> will push f if there is an invalid
        ! hex literal
        [ succ dup 2 + ] dip substring hex> [ >char % ]  when*
    ] ifte ;

: url-decode-% ( index str -- index str )
    2dup url-decode-hex [ 3 + ] dip ;

: url-decode-+-or-other ( index str -- index str )
    CHAR: + CHAR: \s replace % [ succ ] dip ;

: url-decode-iter ( index str -- )
    2dup str-length >= [
        2drop
    ] [
        2dup str-nth dup CHAR: % = [
            drop url-decode-%
        ] [
            url-decode-+-or-other
        ] ifte url-decode-iter
    ] ifte ;

: url-decode ( str -- str )
    <% 0 swap url-decode-iter %> ;