factor/basis/escape-strings/escape-strings.factor

36 lines
1.2 KiB
Factor

! Copyright (C) 2017 John Benediktsson, Doug Coleman.
! See http://factorcode.org/license.txt for BSD license.
USING: assocs assocs.extras combinators kernel math math.order
math.statistics sequences sequences.extras sets ;
IN: escape-strings
: find-escapes ( str -- set )
[ HS{ } clone 0 0 ] dip
[
{
{ CHAR: ] [ 1 + dup 2 = [ drop over adjoin 0 1 ] when ] }
{ CHAR: = [ dup 1 = [ [ 1 + ] dip ] when ] }
[ 3drop 0 0 ]
} case
] each 0 > [ over adjoin ] [ drop ] if ;
: lowest-missing ( set -- min )
members dup [ = not ] find-index
[ nip ] [ drop length ] if ;
: escape-string* ( str n -- str' )
CHAR: = <repetition>
[ "[" dup surround ] [ "]" dup surround ] bi surround ;
: escape-string ( str -- str' )
dup find-escapes lowest-missing escape-string* ;
: escape-strings ( strs -- str )
[ escape-string ] map concat escape-string ;
: escape-simplest ( str -- str' )
dup { CHAR: ' CHAR: " CHAR: \r CHAR: \n CHAR: \s } counts {
{ [ dup { CHAR: ' CHAR: \r CHAR: \n CHAR: \s } values-of sum 0 = ] [ drop "'" prepend ] }
{ [ dup CHAR: " of not ] [ drop "\"" "\"" surround ] }
[ drop escape-string ]
} cond ;