asciimathml.js

数值计算方法网络课件系统是浙江大学过程装备与控制工程专业2001级本科生毕业设计成果。本系统采用ASP＋ACCESS架构

        if (!isIE && typeof symbol.codes != "undefined") {
          for (i=0; i<result[0].childNodes.length; i++)
            if (result[0].childNodes[i].nodeName=="mi" || result[0].nodeName=="mi") {
              st = (result[0].nodeName=="mi"?result[0].firstChild.nodeValue:
                              result[0].childNodes[i].firstChild.nodeValue);
              var newst = [];
              for (var j=0; j<st.length; j++)
                if (st.charCodeAt(j)>64 && st.charCodeAt(j)<91) newst = newst +
                  String.fromCharCode(symbol.codes[st.charCodeAt(j)-65]);
                else newst = newst + st.charAt(j);
              if (result[0].nodeName=="mi")
                result[0]=AMcreateElementMathML("mo").
                          appendChild(document.createTextNode(newst));
              else result[0].replaceChild(AMcreateElementMathML("mo").
          appendChild(document.createTextNode(newst)),result[0].childNodes[i]);
            }
        }
        node = AMcreateMmlNode(symbol.tag,result[0]);
        node.setAttribute(symbol.atname,symbol.atval);
        return [node,result[1]];
      }
    }
  case BINARY:
    str = AMremoveCharsAndBlanks(str,symbol.input.length); 
    result = AMparseSexpr(str);
    if (result[0]==null) return [AMcreateMmlNode("mo",
                           document.createTextNode(symbol.input)),str];
    AMremoveBrackets(result[0]);
    var result2 = AMparseSexpr(result[1]);
    if (result2[0]==null) return [AMcreateMmlNode("mo",
                           document.createTextNode(symbol.input)),str];
    AMremoveBrackets(result2[0]);
    if (symbol==AMroot || symbol==AMover) newFrag.appendChild(result2[0]);
    newFrag.appendChild(result[0]);
    if (symbol==AMfrac) newFrag.appendChild(result2[0]);
    return [AMcreateMmlNode(symbol.tag,newFrag),result2[1]];
  case INFIX:
    str = AMremoveCharsAndBlanks(str,symbol.input.length); 
    return [AMcreateMmlNode("mo",document.createTextNode(symbol.output)),str];
  case SPACE:
    str = AMremoveCharsAndBlanks(str,symbol.input.length); 
    node = AMcreateElementMathML("mspace");
    node.setAttribute("width","1ex");
    newFrag.appendChild(node);
    newFrag.appendChild(
      AMcreateMmlNode(symbol.tag,document.createTextNode(symbol.output)));
    node = AMcreateElementMathML("mspace");
    node.setAttribute("width","1ex");
    newFrag.appendChild(node);
    return [AMcreateMmlNode("mrow",newFrag),str];
  default:
    str = AMremoveCharsAndBlanks(str,symbol.input.length); 
    return [AMcreateMmlNode(symbol.tag,        //its a constant
                             document.createTextNode(symbol.output)),str];
  }
}

function AMparseExpr(str) {
  var symbol, sym1, sym2, node, result, i, underover, nodeList = [],
  newFrag = document.createDocumentFragment();
  do {
    str = AMremoveCharsAndBlanks(str,0);
    sym1 = AMgetSymbol(str);
    result = AMparseSexpr(str);
    node = result[0];
    str = result[1];
    symbol = AMgetSymbol(str);
    if (symbol.ttype == INFIX) {
      str = AMremoveCharsAndBlanks(str,symbol.input.length);
      result = AMparseSexpr(str);
      if (result[0] == null)
        result[0] = AMcreateMmlNode("mo",document.createTextNode("\u25A1"));
      else AMremoveBrackets(result[0]);
      str = result[1];
      if (symbol == AMdiv) AMremoveBrackets(node);
      if (symbol == AMsub) {
        sym2 = AMgetSymbol(str);
        underover = (sym1.ttype == UNDEROVER);
        if (sym2 == AMsup) {
          str = AMremoveCharsAndBlanks(str,sym2.input.length);
          var res2 = AMparseSexpr(str);
          AMremoveBrackets(res2[0]);
          str = res2[1];
          node = AMcreateMmlNode((underover?"munderover":"msubsup"),node);
          node.appendChild(result[0]);
          node.appendChild(res2[0]);
          node = AMcreateMmlNode("mrow",node); // so sum does not stretch
        } else {
          node = AMcreateMmlNode((underover?"munder":"msub"),node);
          node.appendChild(result[0]);
        }
      } else {
        node = AMcreateMmlNode(symbol.tag,node);
        node.appendChild(result[0]);
      }
      newFrag.appendChild(node);
    } 
    else if (node!=undefined) newFrag.appendChild(node);
  } while ((symbol.ttype != RIGHTBRACKET || AMnestingDepth == 0) && 
           symbol!=null && symbol.output!="");
  if (symbol.ttype == RIGHTBRACKET) {
    if (AMnestingDepth > 0) AMnestingDepth--;
    var len = newFrag.childNodes.length;
    if (len>0 && newFrag.childNodes[len-1].nodeName == "mrow" && len>1 &&
      newFrag.childNodes[len-2].nodeName == "mo" &&
      newFrag.childNodes[len-2].firstChild.nodeValue == ",") { //matrix
      var right = newFrag.childNodes[len-1].lastChild.firstChild.nodeValue;
      if (right==")" || right=="]") {
        var left = newFrag.childNodes[len-1].firstChild.firstChild.nodeValue;
        if (left=="(" && right==")" && symbol.output != "}" || 
            left=="[" && right=="]") {
        var pos = []; // positions of commas
        var matrix = true;
        var m = newFrag.childNodes.length;
        for (i=0; matrix && i<m; i=i+2) {
          pos[i] = [];
          node = newFrag.childNodes[i];
          if (matrix) matrix = node.nodeName=="mrow" && 
            (i==m-1 || node.nextSibling.nodeName=="mo" && 
            node.nextSibling.firstChild.nodeValue==",")&&
            node.firstChild.firstChild.nodeValue==left &&
            node.lastChild.firstChild.nodeValue==right;
          if (matrix) 
            for (var j=0; j<node.childNodes.length; j++)
              if (node.childNodes[j].firstChild.nodeValue==",")
                pos[i][pos[i].length]=j;
          if (matrix && i>1) matrix = pos[i].length == pos[i-2].length;
        }
        if (matrix) {
          var row, frag, n, k, table = document.createDocumentFragment();
          for (i=0; i<m; i=i+2) {
            row = document.createDocumentFragment();
            frag = document.createDocumentFragment();
            node = newFrag.firstChild; // <mrow>(-,-,...,-,-)</mrow>
            n = node.childNodes.length;
            k = 0;
            node.removeChild(node.firstChild); //remove (
            for (j=1; j<n-1; j++) {
              if (typeof pos[i][k] != "undefined" && j==pos[i][k]){
                node.removeChild(node.firstChild); //remove ,
                row.appendChild(AMcreateMmlNode("mtd",frag));
                k++;
              } else frag.appendChild(node.firstChild);
            }
            row.appendChild(AMcreateMmlNode("mtd",frag));
            if (newFrag.childNodes.length>2) {
              newFrag.removeChild(newFrag.firstChild); //remove <mrow>)</mrow>
              newFrag.removeChild(newFrag.firstChild); //remove <mo>,</mo>
            }
            table.appendChild(AMcreateMmlNode("mtr",row));
          }
          node = AMcreateMmlNode("mtable",table);
          if (typeof symbol.invisible == "boolean" && symbol.invisible) node.setAttribute("columnalign","left");
          newFrag.replaceChild(node,newFrag.firstChild);
        }
       }
      }
    }
    str = AMremoveCharsAndBlanks(str,symbol.input.length);
    if (typeof symbol.invisible != "boolean" || !symbol.invisible) {
      node = AMcreateMmlNode("mo",document.createTextNode(symbol.output));
      newFrag.appendChild(node);
    }
  }
  return [newFrag,str];
}

function AMparseMath(str) {
  var result, node = AMcreateElementMathML("mstyle");
  if (mathcolor != "") node.setAttribute("mathcolor",mathcolor);
  if (displaystyle) node.setAttribute("displaystyle","true");
  if (mathfontfamily != "") node.setAttribute("fontfamily",mathfontfamily);
  AMnestingDepth = 0;
  node.appendChild(AMparseExpr(str.replace(/^\s+/g,""))[0]);
  node = AMcreateMmlNode("math",node);
  if (mathfontfamily != "") {
    var fnode = AMcreateElementXHTML("font");
    fnode.setAttribute("face",mathfontfamily);
    fnode.appendChild(node);
    return fnode;
  }
  return node;
}

function AMstrarr2docFrag(arr, linebreaks) {
  var newFrag=document.createDocumentFragment();
  var expr = false;
  for (var i=0; i<arr.length; i++) {
    if (expr) newFrag.appendChild(AMparseMath(arr[i]));
    else {
      var arri = (linebreaks ? arr[i].split("\n\n") : [arr[i]]);
      newFrag.appendChild(AMcreateElementXHTML("span").
      appendChild(document.createTextNode(arri[0].
      replace(/AMescape2/g,AMdelimiter2).replace(/AMescape1/g,AMdelimiter1))));
      for (var j=1; j<arri.length; j++) {
        newFrag.appendChild(AMcreateElementXHTML("p"));
        newFrag.appendChild(AMcreateElementXHTML("span").
        appendChild(document.createTextNode(arri[j].
          replace(/AMescape2/g,AMdelimiter2).
          replace(/AMescape1/g,AMdelimiter1))));
      }
    }
    expr = !expr;
  }
  return newFrag;
}

function AMprocessNode(n, linebreaks) {
  var mtch, str, arr;
  if (n.childNodes.length == 0 && (n.nodeType!=8 || linebreaks) &&
    n.parentNode.nodeName!="textarea" && n.parentNode.nodeName!="TEXTAREA" &&
    n.parentNode.nodeName!="pre" && n.parentNode.nodeName!="PRE") {
    str = n.nodeValue;
    if (!(str == null)) {
      str = str.replace(/\r\n\r\n/g,"\n\n");
      if (doubleblankmathdelimiter) {
        str = str.replace(/\x20\x20\./g," "+AMdelimiter1+".");
        str = str.replace(/\x20\x20,/g," "+AMdelimiter1+",");
        str = str.replace(/\x20\x20/g," "+AMdelimiter1+" ");
      }
      str = str.replace(/\x20+/g," ");
      str = str.replace(/\s*\r\n/g," ");
      mtch = false;
      str = str.replace(new RegExp(AMescape2, "g"),
              function(st){mtch=true;return "AMescape2"});
      str = str.replace(new RegExp(AMescape1, "g"),
              function(st){mtch=true;return "AMescape1"});
      str = str.replace(new RegExp(AMdelimiter2regexp, "g"),AMdelimiter1);
      arr = str.split(AMdelimiter1);
      if (arr.length>1 || mtch) {
        if (checkForMathML) {
          checkForMathML = false;
          var nd = AMisMathMLavailable();
          AMnoMathML = nd != null
          if (AMnoMathML && notifyIfNoMathML) 
            AMbody.insertBefore(nd,AMbody.childNodes[0]);
        }
        if (!AMnoMathML)
          n.parentNode.replaceChild(AMstrarr2docFrag(arr,n.nodeType==8),n);
      }
    }
  } else if (n.nodeName!="math") 
    for (var i=0; i<n.childNodes.length; i++)
      AMprocessNode(n.childNodes[i], linebreaks);
}

var AMbody;
var AMnoMathML = false;

function translate() {
  AMinitSymbols();
  AMbody = document.getElementsByTagName("body")[0];
  AMprocessNode(AMbody, false);
  if (isIE) { //needed to match size and font of formula to surrounding text
    var frag = document.getElementsByTagName('math');
    for (var i=0;i<frag.length;i++) frag[i].update()
  }
}