diff --git a/common/src/lib/expr-eval/expression.mjs b/common/src/lib/expr-eval/expression.mjs index f782fa3..89831c7 100644 --- a/common/src/lib/expr-eval/expression.mjs +++ b/common/src/lib/expr-eval/expression.mjs @@ -111,7 +111,7 @@ function simplify(tokens, unaryOps, binaryOps, ternaryOps, values) { * In the given instructions, replaces variable by expr. * @param {Instruction[]} tokens * @param {string} variable - * @param {ExprEvalExpression} expr + * @param {number} expr * @return {Instruction[]} */ function substitute(tokens, variable, expr) { @@ -171,6 +171,9 @@ function evaluate(tokens, expr, values) { nstack.push(n1 ? !!evaluate(n2, expr, values) : false) } else if(item.value === "or") { nstack.push(n1 ? true : !!evaluate(n2, expr, values)) + } else if(item.value === "=") { + f = expr.binaryOps[item.value] + nstack.push(f(n1, evaluate(n2, expr, values), values)) } else { f = expr.binaryOps[item.value] nstack.push(f(resolveExpression(n1, values), resolveExpression(n2, values))) @@ -487,6 +490,18 @@ export class ExprEvalExpression { return evaluate(this.tokens, this, values) } + /** + * Returns a list of symbols (string of characters) in the expressions. + * Can be functions, constants, or variables. + * @returns {string[]} + */ + symbols(options) { + options = options || {} + const vars = [] + getSymbols(this.tokens, vars, options) + return vars + } + toString() { return expressionToString(this.tokens, false) } diff --git a/common/src/lib/expr-eval/parser.mjs b/common/src/lib/expr-eval/parser.mjs index e27d512..71a1c95 100644 --- a/common/src/lib/expr-eval/parser.mjs +++ b/common/src/lib/expr-eval/parser.mjs @@ -47,7 +47,9 @@ const optionNameMap = { "not": "logical", "?": "conditional", ":": "conditional", + //'=': 'assignment', // Disable assignment "[": "array" + //'()=': 'fndef' // Diable function definition } export class Parser { @@ -107,6 +109,7 @@ export class Parser { and: Polyfill.andOperator, or: Polyfill.orOperator, "in": Polyfill.inOperator, + "=": Polyfill.setVar, "[": Polyfill.arrayIndex } @@ -120,13 +123,18 @@ export class Parser { min: Polyfill.min, max: Polyfill.max, hypot: Math.hypot || Polyfill.hypot, - pyt: Math.hypot || Polyfill.hypot, + pyt: Math.hypot || Polyfill.hypot, // backward compat pow: Math.pow, atan2: Math.atan2, "if": Polyfill.condition, gamma: Polyfill.gamma, "Γ": Polyfill.gamma, roundTo: Polyfill.roundTo, + map: Polyfill.arrayMap, + fold: Polyfill.arrayFold, + filter: Polyfill.arrayFilter, + indexOf: Polyfill.stringOrArrayIndexOf, + join: Polyfill.arrayJoin } // These constants will automatically be replaced the MOMENT they are parsed. @@ -151,6 +159,10 @@ export class Parser { return new ExprEvalExpression(instr, this) } + evaluate(expr, variables) { + return this.parse(expr).evaluate(variables) + } + isOperatorEnabled(op) { const optionName = optionNameMap.hasOwnProperty(op) ? optionNameMap[op] : op const operators = this.options.operators || {} diff --git a/common/src/lib/expr-eval/polyfill.mjs b/common/src/lib/expr-eval/polyfill.mjs index c618aaf..9e8e885 100644 --- a/common/src/lib/expr-eval/polyfill.mjs +++ b/common/src/lib/expr-eval/polyfill.mjs @@ -210,8 +210,9 @@ export function gamma(n) { } export function stringOrArrayLength(s) { - if(Array.isArray(s)) + if(Array.isArray(s)) { return s.length + } return String(s).length } @@ -295,6 +296,58 @@ export function min(array) { } } +export function arrayMap(f, a) { + if(typeof f !== "function") { + throw new EvalError(qsTranslate("error", "First argument to map is not a function.")) + } + if(!Array.isArray(a)) { + throw new EvalError(qsTranslate("error", "Second argument to map is not an array.")) + } + return a.map(function(x, i) { + return f(x, i) + }) +} + +export function arrayFold(f, init, a) { + if(typeof f !== "function") { + throw new EvalError(qsTranslate("error", "First argument to fold is not a function.")) + } + if(!Array.isArray(a)) { + throw new EvalError(qsTranslate("error", "Second argument to fold is not an array.")) + } + return a.reduce(function(acc, x, i) { + return f(acc, x, i) + }, init) +} + +export function arrayFilter(f, a) { + if(typeof f !== "function") { + throw new EvalError(qsTranslate("error", "First argument to filter is not a function.")) + } + if(!Array.isArray(a)) { + throw new EvalError(qsTranslate("error", "Second argument to filter is not an array.")) + } + return a.filter(function(x, i) { + return f(x, i) + }) +} + +export function stringOrArrayIndexOf(target, s) { + if(!(Array.isArray(s) || typeof s === "string")) { + throw new Error(qsTranslate("error", "Second argument to indexOf is not a string or array.")) + } + + return s.indexOf(target) +} + +export function arrayJoin(sep, a) { + if(!Array.isArray(a)) { + throw new Error(qsTranslate("error", "Second argument to join is not an array.")) + } + + return a.join(sep) +} + export function sign(x) { return ((x > 0) - (x < 0)) || +x } diff --git a/common/src/lib/expr-eval/tokens.mjs b/common/src/lib/expr-eval/tokens.mjs index bfaad39..919433c 100644 --- a/common/src/lib/expr-eval/tokens.mjs +++ b/common/src/lib/expr-eval/tokens.mjs @@ -472,7 +472,7 @@ export class TokenStream { this.current = this.newToken(TOP, "==") this.pos++ } else { - return false + this.current = this.newToken(TOP, c) } } else if(c === "!") { if(this.expression.charAt(this.pos + 1) === "=") { diff --git a/common/src/module/expreval.mjs b/common/src/module/expreval.mjs index 8440282..964177c 100644 --- a/common/src/module/expreval.mjs +++ b/common/src/module/expreval.mjs @@ -19,7 +19,7 @@ import { Module } from "./common.mjs" import { Parser } from "../lib/expr-eval/parser.mjs" -const EVAL_VARIABLES = { +const evalVariables = { // Variables not provided by expr-eval.js, needs to be provided manually "pi": Math.PI, "PI": Math.PI, @@ -42,7 +42,7 @@ class ExprParserAPI extends Module { this.currentVars = {} this.#parser = new Parser() - this.#parser.consts = Object.assign({}, this.#parser.consts, EVAL_VARIABLES) + this.#parser.consts = Object.assign({}, this.#parser.consts, evalVariables) this.#parser.functions.integral = this.integral.bind(this) this.#parser.functions.derivative = this.derivative.bind(this) @@ -84,11 +84,11 @@ class ExprParserAPI extends Module { return this.#parser.parse(expression) } - integral(a = null, b = null, ...args) { + integral(a, b, ...args) { let usage1 = qsTranslate("usage", "integral(, , )") let usage2 = qsTranslate("usage", "integral(, , , )") let f = this.parseArgumentsForFunction(args, usage1, usage2) - if(typeof a !== "number" || typeof b !== "number") + if(a == null || b == null) throw EvalError(qsTranslate("usage", "Usage:\n%1\n%2").arg(usage1).arg(usage2)) // https://en.wikipedia.org/wiki/Simpson%27s_rule @@ -101,10 +101,10 @@ class ExprParserAPI extends Module { let usage2 = qsTranslate("usage", "derivative(, , )") let x = args.pop() let f = this.parseArgumentsForFunction(args, usage1, usage2) - if(typeof x !== "number") + if(x == null) throw EvalError(qsTranslate("usage", "Usage:\n%1\n%2").arg(usage1).arg(usage2)) - let derivative_precision = 1e-8 + let derivative_precision = x / 10 return (f(x + derivative_precision / 2) - f(x - derivative_precision / 2)) / derivative_precision } } diff --git a/common/test/module/base.mjs b/common/test/basics/module-base.mjs similarity index 97% rename from common/test/module/base.mjs rename to common/test/basics/module-base.mjs index be035c0..9a38109 100644 --- a/common/test/module/base.mjs +++ b/common/test/basics/module-base.mjs @@ -17,8 +17,8 @@ */ // Load prior tests -import "../basics/events.mjs" -import "../basics/interface.mjs" +import "./events.mjs" +import "./interface.mjs" import { describe, it } from "mocha" import { expect } from "chai" diff --git a/common/test/module/objects.mjs b/common/test/basics/module-objects.mjs similarity index 85% rename from common/test/module/objects.mjs rename to common/test/basics/module-objects.mjs index 4665232..ffc8076 100644 --- a/common/test/module/objects.mjs +++ b/common/test/basics/module-objects.mjs @@ -17,14 +17,14 @@ */ // Load prior tests -import "./base.mjs" -import "../basics/utils.mjs" +import "./module-base.mjs" +import "./utils.mjs" import { describe, it } from "mocha" import { expect } from "chai" -// import Objects from "../../src/module/objects.mjs" -// -// describe("Module/Objects", function() { -// -// }) \ No newline at end of file +import Objects from "../../src/module/objects.mjs" + +describe("Module/Objects", function() { + +}) \ No newline at end of file diff --git a/common/test/module/settings.mjs b/common/test/basics/module-settings.mjs similarity index 98% rename from common/test/module/settings.mjs rename to common/test/basics/module-settings.mjs index 7ad439a..ea26556 100644 --- a/common/test/module/settings.mjs +++ b/common/test/basics/module-settings.mjs @@ -17,8 +17,8 @@ */ // Load prior tests -import "./base.mjs" -import "../basics/utils.mjs" +import "./module-base.mjs" +import "./utils.mjs" import { describe, it } from "mocha" import { expect } from "chai" diff --git a/common/test/module/expreval.mjs b/common/test/module/expreval.mjs deleted file mode 100644 index 2d075f6..0000000 --- a/common/test/module/expreval.mjs +++ /dev/null @@ -1,389 +0,0 @@ -/** - * LogarithmPlotter - 2D plotter software to make BODE plots, sequences and distribution functions. - * Copyright (C) 2021-2024 Ad5001 - * - * This program is free software: you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation, either version 3 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program. If not, see . - */ - -// Load prior tests -import "./base.mjs" - -import { describe, it } from "mocha" -import { expect } from "chai" - -import ExprEval from "../../src/module/expreval.mjs" - -describe("Module/ExprEval", function() { - describe("#parse.evaluate", function() { - const evaluate = (expr, vals = {}) => ExprEval.parse(expr).evaluate(vals) - it("parses simple mathematical expressions", function() { - expect(evaluate(`"\\'\\"\\\\\\/\\b\\f\\n\\r\\t\\u3509"`)).to.equal(`'"\\/\b\f\n\r\t\u3509`) - expect(evaluate("1")).to.equal(1) - expect(evaluate(" 1 ")).to.equal(1) - expect(evaluate("0xFF")).to.equal(255) - expect(evaluate("0b11")).to.equal(3) - expect(evaluate("-1")).to.equal(-1) - expect(evaluate("-(-1)")).to.equal(1) - expect(evaluate("+(-1)")).to.equal(-1) - expect(evaluate("3!")).to.equal(6) - expect(evaluate("1+1")).to.equal(2) - expect(evaluate("4*3")).to.equal(12) - expect(evaluate("4•3")).to.equal(12) - expect(evaluate("64/4")).to.equal(16) - expect(evaluate("2^10")).to.equal(1024) - expect(evaluate("10%3")).to.equal(1) - expect(evaluate("10%3")).to.equal(1) - // Test priorities - expect(evaluate("10*10+10*10")).to.equal(200) - expect(evaluate("10/10+10/10")).to.equal(2) - expect(evaluate("10/10+10/10")).to.equal(2) - expect(evaluate("2^2-2^2")).to.equal(0) - expect(evaluate("(2^2-2)^2")).to.equal(4) - }) - - it("parses equality and test statements", function() { - expect(evaluate("10%3 == 1 ? 2 : 1")).to.equal(2) - expect(evaluate("not(10%3 == 1) ? 2 : 1")).to.equal(1) - expect(evaluate("10%3 != 1 ? 2 : 1")).to.equal(1) - expect(evaluate("10 < 3 ? 2 : 1")).to.equal(1) - expect(evaluate("10 > 3 ? (2+1) : 1")).to.equal(3) - expect(evaluate("10 <= 3 ? 4 : 1")).to.equal(1) - expect(evaluate("10 >= 3 ? 4 : 1")).to.equal(4) - // Check equality - expect(evaluate("10 < 10 ? 2 : 1")).to.equal(1) - expect(evaluate("10 > 10 ? 2 : 1")).to.equal(1) - expect(evaluate("10 <= 10 ? 4 : 1")).to.equal(4) - expect(evaluate("10 >= 10 ? 4 : 1")).to.equal(4) - // Check 'and' and 'or' - expect(evaluate("10 <= 3 and 10 < 10 ? 4 : 1")).to.equal(1) - expect(evaluate("10 <= 10 and 10 < 10 ? 4 : 1")).to.equal(1) - expect(evaluate("10 <= 10 and 10 < 20 ? 4 : 1")).to.equal(4) - expect(evaluate("10 <= 3 or 10 < 10 ? 4 : 1")).to.equal(1) - expect(evaluate("10 <= 10 or 10 < 10 ? 4 : 1")).to.equal(4) - expect(evaluate("10 <= 10 or 10 < 20 ? 4 : 1")).to.equal(4) - }) - - it("parses singular function operators (functions with one arguments and no parenthesis)", function() { - // Trigonometric functions - expect(evaluate("sin 0")).to.be.approximately(0, Number.EPSILON) - expect(evaluate("cos 0")).to.be.approximately(1, Number.EPSILON) - expect(evaluate("tan 0")).to.be.approximately(0, Number.EPSILON) - expect(evaluate("asin 1")).to.be.approximately(Math.PI / 2, Number.EPSILON) - expect(evaluate("acos 1")).to.be.approximately(0, Number.EPSILON) - expect(evaluate("atan 1")).to.be.approximately(Math.PI / 4, Number.EPSILON) - expect(evaluate("sinh 1")).to.be.approximately(Math.sinh(1), Number.EPSILON) - expect(evaluate("cosh 1")).to.be.approximately(Math.cosh(1), Number.EPSILON) - expect(evaluate("tanh 1")).to.be.approximately(Math.tanh(1), Number.EPSILON) - expect(evaluate("asinh 1")).to.be.approximately(Math.asinh(1), Number.EPSILON) - expect(evaluate("acosh 1")).to.be.approximately(Math.acosh(1), Number.EPSILON) - expect(evaluate("atanh 0.5")).to.be.approximately(Math.atanh(0.5), Number.EPSILON) - // Reverse trigonometric - expect(evaluate("asin sin 1")).to.be.approximately(1, Number.EPSILON) - expect(evaluate("acos cos 1")).to.be.approximately(1, Number.EPSILON) - expect(evaluate("atan tan 1")).to.be.approximately(1, Number.EPSILON) - expect(evaluate("asinh sinh 1")).to.be.approximately(1, Number.EPSILON) - expect(evaluate("acosh cosh 1")).to.be.approximately(1, Number.EPSILON) - expect(evaluate("atanh tanh 1")).to.be.approximately(1, Number.EPSILON) - // Other functions - expect(evaluate("sqrt 4")).to.be.approximately(2, Number.EPSILON) - expect(evaluate("sqrt 2")).to.be.approximately(Math.sqrt(2), Number.EPSILON) - expect(evaluate("cbrt 27")).to.be.approximately(3, Number.EPSILON) - expect(evaluate("cbrt 14")).to.be.approximately(Math.cbrt(14), Number.EPSILON) - expect(evaluate("log 1")).to.be.approximately(Math.log(1), Number.EPSILON) - expect(evaluate("ln 1")).to.be.approximately(Math.log(1), Number.EPSILON) - expect(evaluate("log2 8")).to.be.approximately(3, Number.EPSILON) - expect(evaluate("log10 100")).to.be.approximately(2, Number.EPSILON) - expect(evaluate("lg 100")).to.be.approximately(2, Number.EPSILON) - expect(evaluate("expm1 0")).to.be.approximately(0, Number.EPSILON) - expect(evaluate("expm1 10")).to.be.approximately(Math.expm1(10), Number.EPSILON) - expect(evaluate("log1p 0")).to.be.approximately(0, Number.EPSILON) - expect(evaluate("log1p 10")).to.be.approximately(Math.log1p(10), Number.EPSILON) - // Roundings/Sign transformations - expect(evaluate("abs -12.34")).to.equal(12.34) - expect(evaluate("abs 12.45")).to.equal(12.45) - expect(evaluate("ceil 12.45")).to.equal(13) - expect(evaluate("ceil 12.75")).to.equal(13) - expect(evaluate("ceil 12.0")).to.equal(12) - expect(evaluate("ceil -12.6")).to.equal(-12) - expect(evaluate("floor 12.45")).to.equal(12) - expect(evaluate("floor 12.75")).to.equal(12) - expect(evaluate("floor 12.0")).to.equal(12) - expect(evaluate("floor -12.2")).to.equal(-13) - expect(evaluate("round 12.45")).to.equal(12) - expect(evaluate("round 12.75")).to.equal(13) - expect(evaluate("round 12.0")).to.equal(12) - expect(evaluate("round -12.2")).to.equal(-12) - expect(evaluate("round -12.6")).to.equal(-13) - expect(evaluate("trunc 12.45")).to.equal(12) - expect(evaluate("trunc 12.75")).to.equal(12) - expect(evaluate("trunc 12.0")).to.equal(12) - expect(evaluate("trunc -12.2")).to.equal(-12) - expect(evaluate("exp 1")).to.be.approximately(Math.E, Number.EPSILON) - expect(evaluate("exp 10")).to.be.approximately(Math.pow(Math.E, 10), 1e-8) - expect(evaluate("length \"string\"")).to.equal(6) - expect(evaluate("sign 0")).to.equal(0) - expect(evaluate("sign -0")).to.equal(0) - expect(evaluate("sign -10")).to.equal(-1) - expect(evaluate("sign 80")).to.equal(1) - }) - - it("parses regular functions", function() { - for(let i = 0; i < 1000; i++) { - expect(evaluate("random()")).to.be.within(0, 1) - expect(evaluate("random(100)")).to.be.within(0, 100) - } - expect(evaluate("fac(3)")).to.equal(6) - expect(evaluate("fac(10)")).to.equal(3628800) - expect(evaluate("min(10, 20)")).to.equal(10) - expect(evaluate("min(-10, -20)")).to.equal(-20) - expect(evaluate("max(10, 20)")).to.equal(20) - expect(evaluate("max(-10, -20)")).to.equal(-10) - expect(evaluate("hypot(3, 4)")).to.equal(5) - expect(evaluate("pyt(30, 40)")).to.equal(50) - expect(evaluate("atan2(1, 1)")).to.be.approximately(Math.PI / 4, Number.EPSILON) - expect(evaluate("atan2(1, 0)")).to.be.approximately(Math.PI / 2, Number.EPSILON) - expect(evaluate("atan2(0, 1)")).to.be.approximately(0, Number.EPSILON) - expect(evaluate("if(10 == 10, 1, 0)")).to.be.approximately(1, Number.EPSILON) - expect(evaluate("if(10 != 10, 1, 0)")).to.be.approximately(0, Number.EPSILON) - expect(evaluate("gamma(10) == 9!")).to.be.true - expect(evaluate("Γ(30) == 29!")).to.be.true - expect(evaluate("Γ(25) == 23!")).to.be.false - expect(evaluate("roundTo(26.04)")).to.equal(26) - expect(evaluate("roundTo(26.04, 2)")).to.equal(26.04) - expect(evaluate("roundTo(26.04836432123, 5)")).to.equal(26.04836) - expect(evaluate("roundTo(26.04836432123, 5)")).to.equal(26.04836) - }) - - it("parses arrays and access their members", function() { - expect(evaluate("[6, 7, 9]")).to.have.lengthOf(3) - expect(evaluate("[6, 7, 9]")).to.deep.equal([6, 7, 9]) - expect(evaluate("[6, \"8\", 9]")).to.have.lengthOf(3) - expect(evaluate("[6, 7%2]")).to.deep.equal([6, 1]) - // Access array indices - expect(evaluate("[6, 7][1]")).to.equal(7) - expect(evaluate("[6, 7, 8, 9, 10][2*2-1]")).to.equal(9) - }) - - it("can apply functions to arrays", function() { - expect(evaluate("length [6, 7, 9]")).to.equal(3) - expect(evaluate("length [6, 7, 8, 9]")).to.equal(4) - expect(evaluate("[6, 7, 9]||[10,11,12]")).to.deep.equal([6, 7, 9, 10, 11, 12]) - expect(evaluate("6 in [6, 7, 9]")).to.be.true - expect(evaluate("2 in [6, 7, 9]")).to.be.false - expect(evaluate("min([10, 6, 7, 8, 9])")).to.equal(6) - expect(evaluate("max([6, 7, 8, 9, 2])")).to.equal(9) - }) - - it("throws errors when invalid function parameters are provided", function() { - expect(() => evaluate("max()")).to.throw() - expect(() => evaluate("min()")).to.throw() - }) - - it("parses constants", function() { - expect(evaluate("pi")).to.equal(Math.PI) - expect(evaluate("PI")).to.equal(Math.PI) - expect(evaluate("π")).to.equal(Math.PI) - expect(evaluate("e")).to.equal(Math.E) - expect(evaluate("E")).to.equal(Math.E) - expect(evaluate("true")).to.be.true - expect(evaluate("false")).to.be.false - // expect(evaluate("∞")).to.equal(Math.Infinity) - // expect(evaluate("infinity")).to.equal(Math.Infinity) - // expect(evaluate("Infinity")).to.equal(Math.Infinity) - }) - - it("can be provided variables", function() { - const u = [1, 2, 3, 4] - const x = 10 - const s_ = "string" - const f = (x) => x * 2 - expect(evaluate("u", { u })).to.deep.equal([...u]) - expect(evaluate("x", { x })).to.equal(x) - expect(evaluate("s_", { s_ })).to.equal(s_) - expect(evaluate("f", { f })).to.equal(f) - expect(evaluate("b", { b: true })).to.equal(true) - expect(evaluate("u[1]", { u })).to.equal(u[1]) - expect(evaluate("x/2", { x })).to.equal(x / 2) - expect(evaluate("f(2)", { f })).to.equal(f(2)) - expect(evaluate("if(x == f(2), u[0], s_)", { x, u, s_, f })).to.equal(s_) - }) - - it("can be provided objects", function() { - const obj = { execute: (x) => x * 3, x: 10, y: { cached: true, execute: () => 20 } } - expect(evaluate("O(3)+O(2)", { O: obj })).to.equal(9 + 6) - expect(evaluate("O.x+O.y", { O: obj })).to.equal(30) - }) - - it("throws errors when trying to use variables wrongly", function() { - const obj = { execute: (x) => x * 3 } - expect(() => evaluate("O()", { O: obj })).to.throw() - expect(() => evaluate("O.x", { O: obj })).to.throw() - expect(() => evaluate("x()", { x: 10 })).to.throw() - expect(() => evaluate("x")).to.throw() - expect(() => evaluate("n")).to.throw() - }) - - it("can do it all at once", function() { - const obj = { execute: (x) => x * 3, x: 20 } - const u = [1, 2, 3, 4] - const x = 10 - const s = "string" - const expr = "random(e) <= e ? fac(x)+u[2]+O(pi) : O.x+length s" - expect(evaluate(expr, { x, u, s, O: obj })).to.equal(3628803 + obj.execute(Math.PI)) - }) - - it("cannot parse invalid expressions", function() { - expect(() => evaluate("1+")).to.throw() - expect(() => evaluate("@")).to.throw() - expect(() => evaluate("]")).to.throw() - expect(() => evaluate("")).to.throw() - expect(() => evaluate(`"\\u35P2"`)).to.throw() - expect(() => evaluate(`"\\x"`)).to.throw() - }) - }) - - describe("#parse.toString", function() { - it("can be converted back into a string without changes", function() { - const expressions = ["pi+2*(e+2)^4", "sin(1+2!+pi+cos -3)^2", "[2,3,4][(2-1)*2]", "true ? false : true"] - for(const ogString of expressions) { - const expr = ExprEval.parse(ogString) - const convertedString = expr.toString() - expect(ExprEval.parse(convertedString)).to.deep.equal(expr) // Can be reparsed just the same - } - }) - }) - - describe("#parse.substitute", function() { - const parsed = ExprEval.parse("if(x == 0, 1, 2+x)") - it("can substitute a variable for a number", function() { - expect(parsed.substitute("x", 10).evaluate({})).to.equal(12) - expect(parsed.substitute("x", 0).evaluate({})).to.equal(1) - }) - - it("can substitute a variable for another", function() { - expect(parsed.substitute("x", "b").evaluate({ b: 10 })).to.equal(12) - expect(parsed.substitute("x", "b").evaluate({ b: 0 })).to.equal(1) - }) - - it("can substitute a variable for an expression", function() { - expect(parsed.substitute("x", "sin α").evaluate({ "α": Math.PI / 2 })).to.be.approximately(3, Number.EPSILON) - expect(parsed.substitute("x", "sin α").evaluate({ "α": 0 })).to.equal(1) - expect(parsed.substitute("x", "α == 1 ? 0 : 1").evaluate({ "α": 1 })).to.equal(1) - }) - }) - - describe("#parse.variables", function() { - it("can list all parsed undefined variables", function() { - expect(ExprEval.parse("a+b+x+pi+sin(b)").variables()).to.deep.equal(["a", "b", "x"]) - }) - }) - - describe("#parse.toJSFunction", function() { - const func = ExprEval.parse("not(false) ? a+b+x+1/x : x!+random()+A.x+[][0]").toJSFunction("x", { a: "10", b: "0" }) - expect(func(10)).to.equal(20.1) - expect(func(20)).to.equal(30.05) - }) - - - describe("#integral", function() { - it("returns the integral value between two integers", function() { - expect(ExprEval.integral(0, 1, "1", "t")).to.be.approximately(1, Number.EPSILON) - expect(ExprEval.integral(0, 1, "t", "t")).to.be.approximately(1 / 2, Number.EPSILON) - expect(ExprEval.integral(0, 1, "t^2", "t")).to.be.approximately(1 / 3, Number.EPSILON) - expect(ExprEval.integral(0, 1, "t^3", "t")).to.be.approximately(1 / 4, 0.01) - expect(ExprEval.integral(0, 1, "t^4", "t")).to.be.approximately(1 / 5, 0.01) - - expect(ExprEval.integral(10, 40, "1", "t")).to.equal(30) - expect(ExprEval.integral(20, 40, "1", "t")).to.equal(20) - - expect(ExprEval.integral(0, 10, { execute: (x) => 1 })).to.equal(10) - expect(ExprEval.integral(0, 10, { execute: (x) => x })).to.equal(50) - expect(ExprEval.integral(0, 1, { execute: (x) => Math.pow(x, 2) })).to.equal(1 / 3) - }) - - - it("throws error when provided with invalid arguments", function() { - const noArg1 = () => ExprEval.integral() - const noArg2 = () => ExprEval.integral(0) - const noFunction = () => ExprEval.integral(0, 1) - const invalidObjectProvided = () => ExprEval.integral(0, 1, { a: 2 }) - const notAnObjectProvided = () => ExprEval.integral(0, 1, "string") - const invalidFromProvided = () => ExprEval.integral("ze", 1, "t^2", "t") - const invalidToProvided = () => ExprEval.integral(0, "ze", "t^2", "t") - const notStringProvided1 = () => ExprEval.integral(0, 1, { a: 2 }, { b: 1 }) - const notStringProvided2 = () => ExprEval.integral(0, 1, { a: 2 }, "t") - const notStringProvided3 = () => ExprEval.integral(0, 1, "t^2", { b: 1 }) - const invalidVariableProvided = () => ExprEval.integral(0, 1, "t^2", "93IO74") - const invalidExpressionProvided = () => ExprEval.integral(0, 1, "t^2t", "t") - const invalidVariableInExpression = () => ExprEval.integral(0, 1, "t^2+x", "t") - expect(noArg1).to.throw() - expect(noArg2).to.throw() - expect(noFunction).to.throw() - expect(invalidObjectProvided).to.throw() - expect(invalidFromProvided).to.throw() - expect(invalidToProvided).to.throw() - expect(notAnObjectProvided).to.throw() - expect(notStringProvided1).to.throw() - expect(notStringProvided2).to.throw() - expect(notStringProvided3).to.throw() - expect(invalidVariableProvided).to.throw() - expect(invalidExpressionProvided).to.throw() - expect(invalidVariableInExpression).to.throw() - }) - }) - - describe("#derivative", function() { - const DELTA = 1e-5 - it("returns the derivative value of a function at a given number", function() { - expect(ExprEval.derivative("1", "t", 2)).to.be.approximately(0, DELTA) - expect(ExprEval.derivative("t", "t", 2)).to.be.approximately(1, DELTA) - expect(ExprEval.derivative("t^2", "t", 2)).to.be.approximately(4, DELTA) - expect(ExprEval.derivative("t^3", "t", 2)).to.be.approximately(12, DELTA) - expect(ExprEval.derivative("t^4", "t", 2)).to.be.approximately(32, DELTA) - - expect(ExprEval.derivative({ execute: (x) => 1 }, 10)).to.equal(0) - expect(ExprEval.derivative({ execute: (x) => x }, 10)).to.be.approximately(1, DELTA) - expect(ExprEval.derivative({ execute: (x) => Math.pow(x, 2) }, 10)).to.be.approximately(20, DELTA) - }) - - it("throws error when provided with invalid arguments", function() { - const noArg1 = () => ExprEval.derivative() - const noArg2 = () => ExprEval.derivative("1") - const noValue1 = () => ExprEval.derivative("0", "1") - const noValue2 = () => ExprEval.derivative({ execute: (x) => 1 }) - const invalidObjectProvided = () => ExprEval.derivative({ a: 2 }, 1) - const notAnObjectProvided = () => ExprEval.derivative("string", 1) - const invalidXProvided = () => ExprEval.derivative("t^2+x", "t", "ze") - const notStringProvided1 = () => ExprEval.derivative({ a: 2 }, { b: 1 }, 1) - const notStringProvided2 = () => ExprEval.derivative({ a: 2 }, "t", 1) - const notStringProvided3 = () => ExprEval.derivative("t^2", { b: 1 }, 1) - const invalidVariableProvided = () => ExprEval.derivative("t^2", "93IO74", 1) - const invalidExpressionProvided = () => ExprEval.derivative("t^2t", "t", 1) - const invalidVariableInExpression = () => ExprEval.derivative("t^2+x", "t", 1) - expect(noArg1).to.throw() - expect(noArg2).to.throw() - expect(noValue1).to.throw() - expect(noValue2).to.throw() - expect(invalidObjectProvided).to.throw() - expect(invalidXProvided).to.throw() - expect(notAnObjectProvided).to.throw() - expect(notStringProvided1).to.throw() - expect(notStringProvided2).to.throw() - expect(notStringProvided3).to.throw() - expect(invalidVariableProvided).to.throw() - expect(invalidExpressionProvided).to.throw() - expect(invalidVariableInExpression).to.throw() - }) - }) -}) \ No newline at end of file