Better handling of constants in simplified expressions.

LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/js/expr-eval.js

@@ -521,7 +521,7 @@ Expression.prototype.substitute = function (variable, expr) {
 };
 
 Expression.prototype.evaluate = function (values) {
-  values = values || {};
+  values = Object.assign({}, values, this.parser.consts)
   return evaluate(this.tokens, this, values);
 };
 
@@ -541,8 +541,9 @@ Expression.prototype.variables = function (options) {
   var vars = [];
   getSymbols(this.tokens, vars, options);
   var functions = this.functions;
+  var consts = this.parser.consts
   return vars.filter(function (name) {
-    return !(name in functions);
+    return !(name in functions) && !(name in consts);
   });
 };
 
@@ -580,7 +581,7 @@ function TokenStream(parser, expression) {
   this.unaryOps = parser.unaryOps;
   this.binaryOps = parser.binaryOps;
   this.ternaryOps = parser.ternaryOps;
-  this.consts = parser.consts;
+  this.builtinConsts = parser.builtinConsts;
   this.expression = expression;
   this.savedPosition = 0;
   this.savedCurrent = null;
@@ -700,8 +701,8 @@ TokenStream.prototype.isConst = function () {
   }
   if (i > startPos) {
     var str = this.expression.substring(startPos, i);
-    if (str in this.consts) {
-      this.current = this.newToken(TNUMBER, this.consts[str]);
+    if (str in this.builtinConsts) {
+      this.current = this.newToken(TNUMBER, this.builtinConsts[str]);
       this.pos += str.length;
       return true;
     }
@@ -1792,12 +1793,12 @@ class Parser {
       join: arrayJoin
     };
     
-    this.consts = {
-      E: Math.E,
-      PI: Math.PI,
-      'true': true,
-      'false': false
-    };
+    // These constants will automatically be replaced the MOMENT they are parsed.
+    // (Original consts from the parser)
+    this.builtinConsts = {};
+    // These consts will only be replaced when the expression is evaluated.
+    this.consts = {}
+    
   }
   
   parse(expr) {

LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/js/math/common.js

@@ -26,13 +26,17 @@ const DERIVATION_PRECISION = 0.1
 
 var evalVariables = { // Variables not provided by expr-eval.js, needs to be provided manually
     "pi": Math.PI,
+    "PI": Math.PI,
     "π": Math.PI,
     "inf": Infinity,
     "infinity": Infinity,
     "Infinity": Infinity,
     "∞": Infinity,
     "e": Math.E,
-    "E": Math.E
+    "E": Math.E,
+    "true": true,
+    "false": false
+    
 }
 
 var currentVars = {}
@@ -54,3 +58,4 @@ parser.functions.derivative = function(f, variable, x) {
     f = parser.parse(f).toJSFunction(variable, currentVars)
     return (f(x+DERIVATION_PRECISION/2)-f(x-DERIVATION_PRECISION/2))/DERIVATION_PRECISION
 }
+

LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/js/math/expression.js

@@ -27,8 +27,8 @@
  */
 class Expression {
     constructor(expr) {
-        this.expr = expr
-        this.calc = C.parser.parse(expr).simplify()
+        this.expr = Utils.exponentsToExpression(expr)
+        this.calc = C.parser.parse(this.expr).simplify()
         this.cached = this.isConstant()
         this.cachedValue = this.cached && this.allRequirementsFullfilled() ? this.calc.evaluate(C.currentObjectsByName) : null
         this.latexMarkup = Latex.expression(this.calc.tokens)

LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/js/utils.js

@@ -62,6 +62,11 @@ var powerpos = {
     "z": "ᶻ"
 }
 
+var exponents = [
+    "⁰","¹","²","³","⁴","⁵","⁶","⁷","⁸","⁹"
+]
+var exponentReg = new RegExp('(['+exponents.join('')+']+)', 'g')
+
 var indicepos = {
     "-": "₋",
     "+": "₊",
@@ -351,3 +356,14 @@ function getRandomColor() {
 function escapeHTML(str) {
     return str.replace(/&/g,'&amp;').replace(/</g,'&lt;').replace(/>/g,'&gt;') ;
 }
+
+
+
+/**
+ * Parses exponents and replaces them with expression values
+ * @param {string} expression - The expression to replace in.
+ * @return {string} The parsed expression
+ */
+function exponentsToExpression(expression) {
+    return expression.replace(exponentReg, (m, exp) => '^' + exp.split('').map((x) => exponents.indexOf(x)).join(''))
+}

README.md

@@ -79,4 +79,4 @@ Language files translations located at LogarithmPlotter/i18n are licensed under
 
 LogarithmPlotter includes [expr-eval](https://github.com/silentmatt/expr-eval) a port of [ndef.parser](https://web.archive.org/web/20111023001618/http://www.undefined.ch/mparser/index.html) by Raphael Graf <r@undefined.ch>, ported to javascript by Matthew Crumley <email@matthewcrumley.com> (http://silentmatt.com/), and then to QMLJS by Ad5001.
 
-The code is licensed under the [MIT License](https://raw.githubusercontent.com/silentmatt/expr-eval/master/LICENSE.txt).
+The specific file (LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/js/expr-eval.js) is licensed under the [MIT License](https://raw.githubusercontent.com/silentmatt/expr-eval/master/LICENSE.txt).