64 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			Factor
		
	
	
			
		
		
	
	
			64 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			Factor
		
	
	
! Copyright (C) 2013-2014 Björn Lindqvist
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! See http://factorcode.org/license.txt for BSD license
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USING: accessors ascii base64 fry grouping.extras io
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io.encodings io.encodings.string io.encodings.utf16 kernel math
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math.functions sequences splitting strings ;
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IN: io.encodings.utf7
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TUPLE: utf7codec dialect buffer ;
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! These words encodes the difference between standard utf7 and the
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! dialect used by IMAP which wants slashes replaced with commas when
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! encoding and uses '&' instead of '+' as the escaping character.
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: utf7 ( -- utf7codec )
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    {
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        { { } { } }
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        { { CHAR: + } { CHAR: - } }
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    } V{ } utf7codec boa ;
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: utf7imap4 ( -- utf7codec )
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    {
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        { { CHAR: / } { CHAR: , } }
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        { { CHAR: & } { CHAR: - } }
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    } V{ } utf7codec boa ;
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: >raw-base64 ( bytes -- bytes' )
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    >string utf16be encode >base64 [ CHAR: = = ] trim-tail ;
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: raw-base64> ( str -- str' )
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    dup length 4 / ceiling 4 * CHAR: = pad-tail base64> utf16be decode ;
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: encode-chunk ( repl-pair surround-pair chunk ascii? -- bytes )
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    [ swap [ first ] [ concat ] bi replace nip ]
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    [ >raw-base64 -rot [ first2 replace ] [ first2 surround ] bi* ] if ;
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: encode-utf7-string ( str codec -- bytes )
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    [ [ printable? ] group-by ] dip
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    dialect>> first2 '[ _ _ rot first2 swap encode-chunk ] map
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    B{ } concat-as ;
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M: utf7codec encode-string ( str stream codec -- )
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    swapd encode-utf7-string swap stream-write ;
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DEFER: emit-char
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: decode-chunk ( dialect -- ch buffer )
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    dup first2 swap [ second read-until drop ] [ first2 swap replace ] bi*
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    [ second first first { } ] [ raw-base64> emit-char ] if-empty ;
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: fill-buffer ( dialect -- ch buffer )
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    dup second first first read1 dup swapd = [
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        drop decode-chunk
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    ] [ nip { } ] if ;
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: emit-char ( dialect buffer -- ch buffer' )
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    [ fill-buffer ] [ nip unclip swap ] if-empty ;
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: replace-all! ( src dst -- )
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    [ delete-all ] keep push-all ;
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M: utf7codec decode-char ( stream codec -- char/f )
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    swap [
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        [ dialect>> ] [ buffer>> ] bi [ emit-char ] keep replace-all!
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    ] with-input-stream ;
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