#!/home/arne/wisp/wisp-multiline.sh 
; !#

; we need to be able to replace end-of-line characters in brackets and strings

;; nostringandbracketbreaks INPORT
;; 
;; Replace linebreaks within brackets and strings in the INPORT by the
;; placeholders \\STRING_BREAK_N and \\STRING_BREAK_R.
;; 
;; -Author: Arne Babenhauserheide
define : nostringandbracketbreaks inport
    ; Replace end of line characters in brackets and strings
    ; FIXME: Breaks if the string is shorter than 2 chars
    let* 
        : lastchar : read-char inport
          nextchar : read-char inport
          text ""
          incomment #f
          instring #f
          inbrackets 0
          incharform 0 ; #\<something>
        while : not : eof-object? nextchar
            ; already started char forms win over everything, so process them first.
            ; already started means: after the #\
            when : >= incharform 2
                if : char=? nextchar #\space
                   set! incharform 0
                   ; else
                   set! incharform : + incharform 1
            ; check if we switch to a string: last char is space, linebreak or in a string, not in a charform, not in a comment
            when 
                 and 
                     char=? nextchar #\"
                     or 
                        . instring ; when I’m in a string, I can get out
                        char=? lastchar #\space ; when the last char was a space, I can get into a string
                        char=? lastchar #\linefeed ; same for newline chars
                        char=? lastchar #\newline
                     not incomment
                     < incharform 1
                set! instring : not instring
            ; check if we switch to a comment
            when 
                 and 
                     char=? nextchar #\;
                     not incomment
                     not instring
                     < incharform 2
                set! incomment #t
                ; this also closes any potential charform
                set! incharform 0
            when
                and incomment
                    or 
                        char=? nextchar #\newline
                        char=? nextchar #\linefeed
                set! incomment #f
            
            ; check for the beginning of a charform
            when 
                and
                    not instring
                    not incomment
                    char=? lastchar #\space
                    char=? nextchar #\#
                set! incharform 1
            ; check whether a charform is continued
            when
                and
                     = incharform 1
                     char=? lastchar #\#
                     char=? nextchar #\\
                set! incharform 2
                        
            ; check for brackets
            when : and ( char=? nextchar #\( ) ( not instring ) ( not incomment ) ( = incharform 0 )
                set! inbrackets : + inbrackets 1
            when : and ( char=? nextchar #\) ) ( not instring ) ( not incomment ) ( = incharform 0 )
                set! inbrackets : - inbrackets 1

            if : or instring ( > inbrackets 0 )
                if : char=? nextchar #\linefeed
                    set! text : string-append text "\\LINE_BREAK_N"
                    if : char=? nextchar #\newline
                        set! text : string-append text "\\LINE_BREAK_R"
                        set! text : string-append text : string nextchar
                ; when not in brackets or string: just append the char
                set! text : string-append text : string nextchar

            set! lastchar nextchar
            set! nextchar : read-char inport
        ; return the text
        . text


; first step: Be able to mirror a file to stdout

let* 
    : filename : list-ref ( command-line ) 1
      origfile : open-file filename "r" ; mode
      nextchar : read-char origfile
      text ""
    while : not : eof-object? nextchar
        set! text : string-append text : string nextchar
        set! nextchar : read-char origfile
    set! text : call-with-input-string text nostringandbracketbreaks
    display text

newline