Adding object properties usable in expressions

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

@@ -194,6 +194,7 @@ function evaluate(tokens, expr, values) {
         nstack.push(f(resolveExpression(n1, values), resolveExpression(n2, values), resolveExpression(n3, values)));
       }
     } else if (type === IVAR) {
+      // Check for variable value
       if (item.value in expr.functions) {
         nstack.push(expr.functions[item.value]);
       } else if (item.value in expr.unaryOps && expr.parser.isOperatorEnabled(item.value)) {
@@ -219,8 +220,11 @@ function evaluate(tokens, expr, values) {
       f = nstack.pop();
       if (f.apply && f.call) {
         nstack.push(f.apply(undefined, args));
+      } else if(f.execute) {
+        // Objects & expressions execution
+        nstack.push(f.execute.apply(undefined, args));
       } else {
-        throw new Error(f + ' is not a function');
+        throw new Error(f + ' cannot be executed');
       }
     } else if (type === IFUNDEF) {
       // Create closure to keep references to arguments and expression

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

@@ -22,7 +22,9 @@
 .import "../utils.js" as Utils
 .import "latex.js" as Latex
 
-var evalVariables = { // Variables not provided by expr-eval.js, needs to be provided manualy
+const DERIVATION_PRECISION = 0.1
+
+var evalVariables = { // Variables not provided by expr-eval.js, needs to be provided manually
     "pi": Math.PI,
     "π": Math.PI,
     "inf": Infinity,
@@ -33,18 +35,21 @@ var evalVariables = { // Variables not provided by expr-eval.js, needs to be pro
 }
 
 var currentVars = {}
+var currentObjectsByName = {} // Mirror of currentObjectsByName in objects.js
 
 const parser = new ExprEval.Parser()
+
+parser.consts = Object.assign({}, parser.consts, evalVariables)
+
+// Function definition
 parser.functions.integral = function(a, b, f, variable) {
     // https://en.wikipedia.org/wiki/Simpson%27s_rule
+    // Simpler, faster than tokenizing the expression
     f = parser.parse(f).toJSFunction(variable, currentVars)
     return (b-a)/6*(f(a)+4*f((a+b)/2)+f(b))
 }
 
-const DERIVATION_PRECISION = 0.1
-
 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

@@ -30,23 +30,25 @@ class Expression {
         this.expr = expr
         this.calc = C.parser.parse(expr).simplify()
         this.cached = this.isConstant()
-        this.cachedValue = this.cached ? this.calc.evaluate(C.evalVariables) : null
+        this.cachedValue = this.cached ? this.calc.evaluate(C.currentObjectsByName) : null
         this.latexMarkup = Latex.expression(this.calc.tokens)
     }
     
     isConstant() {
-        return !this.expr.includes("x") && !this.expr.includes("n")
+        let vars = this.calc.variables()
+        return !vars.includes("x") && !vars.includes("n")
     }
     
     execute(x = 1) {
         if(this.cached) return this.cachedValue
-        C.currentVars = Object.assign({'x': x}, C.evalVariables)
+        C.currentVars = Object.assign({'x': x}, C.currentObjectsByName)
+        //console.log("Executing", this.expr, "with", JSON.stringify(C.currentVars))
         return this.calc.evaluate(C.currentVars)
     }
     
     simplify(x) {
         var expr = this.calc.substitute('x', x).simplify()
-        if(expr.evaluate(C.evalVariables) == 0) return '0'
+        if(expr.evaluate() == 0) return '0'
         var str = Utils.makeExpressionReadable(expr.toString());
         if(str != undefined && str.match(/^\d*\.\d+$/)) {
             if(str.split('.')[1].split('0').length > 7) {

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

@@ -39,7 +39,7 @@ class Sequence extends Expr.Expression {
             if(['string', 'number'].includes(typeof this.calcValues[n])) {
                 let parsed = C.parser.parse(this.calcValues[n].toString()).simplify()
                 this.latexValues[n] = Latex.expression(parsed.tokens)
-                this.calcValues[n] = parsed.evaluate(C.evalVariables)
+                this.calcValues[n] = parsed.evaluate()
             }
         this.valuePlus = parseInt(valuePlus)
     }
@@ -65,9 +65,10 @@ class Sequence extends Expr.Expression {
     cache(n = 1) {
         var str = Utils.simplifyExpression(this.calc.substitute('n', n-this.valuePlus).toString())
         var expr = C.parser.parse(str).simplify()
-        var l = {'n': n-this.valuePlus} // Just in case, add n (for custom functions)
+        C.currentVars = Object.assign(
-        l[this.name] = this.calcValues
+            {'n': n-this.valuePlus, [this.name]: this.calcValues}, // Just in case, add n (for custom functions)
-        C.currentVars = Object.assign(l, C.evalVariables)
+            C.currentObjectsByName
+        )
         this.calcValues[n] = expr.evaluate(C.currentVars)
     }
     

LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/js/objects.js

@@ -19,14 +19,15 @@
 .pragma library
 
 .import "utils.js" as Utils
-.import "mathlib.js" as MathLib
+.import "math/common.js" as MathCommons
 .import "parameters.js" as P
 
 var types = {}
 
 var currentObjects = {}
 var currentObjectsByName = {}
-
+MathCommons.currentObjectsByName = currentObjectsByName // Required for using objects in variables.
+ 
 function renameObject(oldName, newName) {
     /**
      * Renames an object from its old name to the new one.
@@ -46,7 +47,7 @@ function deleteObject(objName) {
      */
     let obj = currentObjectsByName[objName]
     delete currentObjectsByName[objName]
-    currentObjects[obj.type].splice(currentObjects.indexOf(obj),1)
+    currentObjects[obj.type].splice(currentObjects[obj.type].indexOf(obj),1)
     obj.delete()
 }
 

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

@@ -187,7 +187,7 @@ class DrawableObject {
      * Callback method when one of the properties of the object is updated.
      */
     update() {
-        for(var req of this.requiredBy) {
+        for(let req of this.requiredBy) {
             req.update()
         }
     }