1 files changed, 181 insertions, 0 deletions
diff --git a/mod/hexit.php b/mod/hexit.php
new file mode 100644
index 000000000..2c65fd9d4
--- /dev/null
+++ b/mod/hexit.php
@@ -0,0 +1,181 @@
+<?php
+
+
+
+
+
+
+
+
+
+
+
+
+
+function hexit_content(&$a) {
+
+
+$o .= <<< EOT
+
+<script type="text/javascript">
+/**
+ * A function for converting hex <-> dec w/o loss of precision.
+ *
+ * The problem is that parseInt("0x12345...") isn't precise enough to convert
+ * 64-bit integers correctly.
+ *
+ * Internally, this uses arrays to encode decimal digits starting with the least
+ * significant:
+ * 8 = [8]
+ * 16 = [6, 1]
+ * 1024 = [4, 2, 0, 1]
+ */
+
+// Adds two arrays for the given base (10 or 16), returning the result.
+// This turns out to be the only "primitive" operation we need.
+function add(x, y, base) {
+  var z = [];
+  var n = Math.max(x.length, y.length);
+  var carry = 0;
+  var i = 0;
+  while (i < n || carry) {
+    var xi = i < x.length ? x[i] : 0;
+    var yi = i < y.length ? y[i] : 0;
+    var zi = carry + xi + yi;
+    z.push(zi % base);
+    carry = Math.floor(zi / base);
+    i++;
+  }
+  return z;
+}
+
+// Returns a*x, where x is an array of decimal digits and a is an ordinary
+// JavaScript number. base is the number base of the array x.
+function multiplyByNumber(num, x, base) {
+  if (num < 0) return null;
+  if (num == 0) return [];
+
+  var result = [];
+  var power = x;
+  while (true) {
+    if (num & 1) {
+      result = add(result, power, base);
+    }
+    num = num >> 1;
+    if (num === 0) break;
+    power = add(power, power, base);
+  }
+
+  return result;
+}
+
+function parseToDigitsArray(str, base) {
+  var digits = str.split('');
+  var ary = [];
+  for (var i = digits.length - 1; i >= 0; i--) {
+    var n = parseInt(digits[i], base);
+    if (isNaN(n)) return null;
+    ary.push(n);
+  }
+  return ary;
+}
+
+function convertBase(str, fromBase, toBase) {
+  var digits = parseToDigitsArray(str, fromBase);
+  if (digits === null) return null;
+
+  var outArray = [];
+  var power = [1];
+  for (var i = 0; i < digits.length; i++) {
+    // invariant: at this point, fromBase^i = power
+    if (digits[i]) {
+      outArray = add(outArray, multiplyByNumber(digits[i], power, toBase), toBase);
+    }
+    power = multiplyByNumber(fromBase, power, toBase);
+  }
+
+  var out = '';
+  for (var i = outArray.length - 1; i >= 0; i--) {
+    out += outArray[i].toString(toBase);
+  }
+  return out;
+}
+
+function decToHex(decStr) {
+  var hex = convertBase(decStr, 10, 16);
+  return hex ? '0x' + hex : null;
+}
+
+function hexToDec(hexStr) {
+  if (hexStr.substring(0, 2) === '0x') hexStr = hexStr.substring(2);
+  hexStr = hexStr.toLowerCase();
+  return convertBase(hexStr, 16, 10);
+}
+
+
+
+    function str_or_null(x) {
+      return x === null ? 'null' : x;
+    }
+
+    // "1.234e+5" -> "12340"
+    function expandExponential(x) {
+      var pos = x.indexOf("e");
+      if (pos === -1) pos = x.indexOf("E");
+      if (pos === -1) return x;
+
+      var base = x.substring(0, pos);
+      var pow = parseInt(x.substring(pos + 1), 10);
+      if (pow < 0) return x;  // not supported.
+
+      var dotPos = base.indexOf('.');
+      if (dotPos === -1) dotPos = base.length;
+
+      var ret = base.replace('.', '');
+      while (ret.length < dotPos + pow) ret += '0';
+      return ret;
+    }
+
+    function boldDifference(correct, actual) {
+      for (var i = 0, j = 0; i < correct.length && j < actual.length; i++, j++) {
+        if (correct[i] !== actual[j]) {
+          break;
+        }
+      }
+      if (j < actual.length) {
+        return actual.substring(0, j) + '<b>' + actual.substring(j) + '</b>';
+      } else {
+        return actual;
+      }
+    }
+
+    function convert() {
+      var input = document.getElementById("in").value;
+      if (input) {
+        var aHex = str_or_null(decToHex(input));
+        var aDec = str_or_null(hexToDec(input));
+        var bHex = '0x' + (parseInt(input, 10)).toString(16);
+        var bDec = "" + expandExponential("" +parseInt(input, 16));
+
+        var html = '<p></p><p>To Decimal(' + input + ') = ' + aDec + '</p>';
+        html += '<p>To Hex(' + input + ') = ' + aHex + '</p>';
+        document.getElementById('result').innerHTML = html;
+      }
+    }
+    convert();
+
+
+</script>
+
+	<h2>Hexit</h2>
+
+ <p>Type in a hex or decimal string:</p>
+  <input type="text" size=40 id="in" onkeyup="convert()" value="" />
+  <p id="result"></p>
+
+
+
+EOT;
+
+return $o;
+}