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<html>
<body onload="newbutton();">
<table>
<tr>
<td valign="top">
<div style="border:2px solid black;background-color:#fed;width:500;height:1200;">
<div id="infobox" style="padding:4px;">
</div>
</div>
</td>
</tr>
</table>
</div>
<script lang='Javascript'>
// Token class and storage definition
function token (kind,val,fromchar,tochar,row) {
this.kind = kind;
this.val = val;
this.from = fromchar;
this.to = tochar;
this.row = row;
}
var tokens = []; // Array to hold the tokens.
//----------------------------------------------------------
// Store token in tokens array
// Creates a new token object using the constructor
//----------------------------------------------------------
function maketoken(kind,val,from,to,rowno)
{
newtoken=new token(kind,val,from,to,rowno);
tokens.push(newtoken);
}
//----------------------------------------------------------
// Writes error from tokenizer
//----------------------------------------------------------
function error(str,val,row)
{
alert("Tokenizer Error: "+str+val+" at row "+row);
}
//----------------------------------------------------------
// Tokenize function
// Tokenizer partly based on ideas from the very clever tokenizer written by Douglas Cockford
// The tokenizer is passed a string, and a string of prefix and suffix terminators
//----------------------------------------------------------
function tokenize(instring,inprefix,insuffix){
var from; // index of the start of the token.
var i = 0; // index of the current character.
var length=instring.length; // length of the string
var c; // current character.
var n; // current numerical value
var q; // current quote character
var str; // current string value.
var row=1; // current row value
c = instring.charAt(i);
while (c) {
from = i;
if (c <= ' '){ // White space
if((c=='\n')||(c=='\r')||(c == '')) row++; // Add row if this white space is a row terminator
i++;
c = instring.charAt(i);
}else if ((c >='a'&&c<='z')||(c>='A'&&c<='Z')) { // Names i.e. Text
str = c;
i++;
for (;;) {
c = instring.charAt(i);
if ((c >='a'&&c<='z')||(c>='A'&&c<='Z')||(c>='0'&&c<='9')||c=='_'){
str += c;
i++;
}else{
break;
}
}
maketoken('name',str,from,i,row);
} else if (c >= '0' && c <= '9') { // Number token
str = c;
i++;
for (;;) {
c = instring.charAt(i);
if (c < '0' || c > '9') break;
i++;
str+=c;
}
if(c=='.'){
i++;
str+=c;
for(;;){
c=instring.charAt(i);
if (c < '0' || c > '9') break;
i++;
str+=c;
}
}
if (c=='e'||c=='E') {
i++;
str+=c;
c=instring.charAt(i);
if(c=='-'||c=='+') {
i+=1;
str+=c;
c=instring.charAt(i);
}
if (c < '0' || c > '9') error('Bad Exponent in Number: ',str,row);
do {
i++;
str+=c;
c=instring.charAt(i);
}while(c>='0'&&c<='9');
}
if (c>='a'&&c<='z'){
str += c;
i += 1;
error('Bad Number: ',str,row);
}
n=+str;
if (isFinite(n)) {
maketoken('number',n,from,i,row);
} else {
error('Bad Number: ',str,row);
}
} else if(c=='\''||c=='"'){ // String .. handles c style breaking codes
str='';
q=c;
i++;
for (;;) {
c=instring.charAt(i);
if (c<' '){
if((c=='\n')||(c=='\r')||(c == '')) row++; // Add row if this white space is a row terminator
error('Unterminated String: ',str,row);
}
if (c==q) break;
if (c=='\\'){
i += 1;
if (i >= length) {
error('Unterminated String: ',str,row);
}
c=instring.charAt(i);
if(c=='b'){ c='\b'; break; }
if(c=='f'){ c='\f'; break; }
if(c=='n'){ c='\n'; break; }
if(c=='r'){ c='\r'; break; }
if(c=='t'){ c='\t'; break; }
if(c=='u'){
if (i >= length) {
error('Unterminated String: ',str,row);
}
c = parseInt(this.substr(i + 1, 4), 16);
if (!isFinite(c) || c < 0) {
error('Unterminated String: ',str,row);
}
c = String.fromCharCode(c);
i+=4;
break;
}
}
str += c;
i++;
}
i++;
maketoken('string',str,from,i,row);
c=instring.charAt(i);
} else if (c=='/'&&instring.charAt(i+1)=='/'){ // Comment of // type ... does not cover block comments
i++;
for (;;){
c=instring.charAt(i);
if (c=='\n'||c=='\r'||c=='') {
row++;
break;
}
i++;
}
} else if (c=='/'&&instring.charAt(i+1)=='*'){ // Block comment of /* type
i++;
for (;;){
c=instring.charAt(i);
if ((c=='*'&&instring.charAt(i+1)=='/')||(i==length)) {
i+=2;
c=instring.charAt(i);
break;
}
if (c=='\n'||c=='\r'||c=='') {
row++;
}
i++;
}
}else if(inprefix.indexOf(c) >= 0) { // Multi-character Operators
str = c;
i++;
while (true){
c=instring.charAt(i);
if (i >= length || insuffix.indexOf(c) < 0) {
break;
}
str += c;
i++;
}
maketoken('operator',str,from,i,row);
} else { // Single-character Operators
i++;
maketoken('operator',c,from,i,row);
c = instring.charAt(i);
}
}
}
function newbutton()
{
var funclist;
var oplist;
oplist=document.getElementById('infobox');
string_tokenize="foo // Lederhosen\nsin'foo'(200.0*r)+(-21.4/1.51e-6)+/*Plodder*/(Feeeb+400)*ln(3000);\ncos(200.1-atan2(41.0,51.0));\nHello+85-4*2.6-1.51e-6;";
tokenize(string_tokenize,"<>+-&","=>&:");
// Iterate over token objects and print kind of each token and token type in window
printout=document.getElementById('infobox');
for(i=0;i<tokens.length;i++){
printout.innerHTML+=tokens[i].kind+" "+tokens[i].val+" ("+tokens[i].from+"-"+tokens[i].to+") at: "+tokens[i].row+"<br>";
}
}
</script>
</body>
</html>
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