// Scilab ( http://www.scilab.org/ ) - This file is part of Scilab
// Copyright (C) ???? - INRIA - Scilab
// Copyright (C) 2002-2004 - INRIA - Vincent COUVERT
//
// This file must be used under the terms of the CeCILL.
// This source file is licensed as described in the file COPYING, which
// you should have received as part of this distribution.  The terms
// are also available at
// http://www.cecill.info/licences/Licence_CeCILL_V2.1-en.txt

function r=isinstring(str,pos)
    // Finds if the character pointed by pos is in a string (return %T) or not (return %F)

    str=part(str,1:pos-1)
    quote="''"

    // If no quote in before pos
    if strindex(str,quote)==[] then
        r=%F
        return
    end


    ksym=0
    strcnt=0
    qcount=0 // Quote counter
    bcount=0 // Bracket counter
    pcount=0 // Paranthesis counter
    sym=" "

    while %T ,
        while %T then // Looking for next non white character
            if ksym>=pos then
                r=strcnt<>0;
                return
            end
            ksym=ksym+1;
            psym=sym; // psym = previous symbol
            sym=part(str,ksym);
            if sym<>" " then break,end
        end

        if strcnt<>0 then // If in a string
            if sym==quote then
                qcount=1
                while part(str,ksym+1)<>quote&ksym+1<pos then // Searching for quote or end of string
                    ksym=ksym+1
                end

                // 5 following lines added 25/02/2003 (it seemed to work before...)
                //      if ksym+1<pos then // Added by VC 17/03/2003 because didn't work for following string 'a'.^[1+1i] (pb in i_notation())
                //	qcount=qcount+1
                //      end // Added by VC 17/03/2003
                while part(str,ksym+1)==quote&ksym+1<pos then // Searching for a sequence of quotes
                    ksym=ksym+1
                    qcount=qcount+1
                end
                // End of part added 25/02/2003

                if 2*int(qcount/2)<>qcount then
                    strcnt=0
                    sym=part(str,ksym)
                end
            end
        elseif sym==quote then
            // Check if transpose or beginning of a string
            if abs(_str2code(psym))>=36&psym<>")"&psym<>"]"&psym<>"."&psym<>quote then // Not a transpose
                strcnt=1
            elseif bcount<>0 then // Inside a matrix definition
                if part(str,ksym-1)==" " then strcnt=1,end
            end
        elseif sym=="[" then
            bcount=bcount+1
        elseif sym=="]" then
            bcount=bcount-1
        end
    end
endfunction