1 files changed, 89 insertions, 0 deletions
diff --git a/node_modules/math-expression-evaluator/src/postfix_evaluator.js b/node_modules/math-expression-evaluator/src/postfix_evaluator.js
new file mode 100644
index 00000000..037aa889
--- /dev/null
+++ b/node_modules/math-expression-evaluator/src/postfix_evaluator.js
@@ -0,0 +1,89 @@
+var Mexp = require('./postfix.js')
+Mexp.prototype.postfixEval = function (UserDefined) {
+	'use strict'
+	UserDefined = UserDefined || {}
+	UserDefined.PI = Math.PI
+	UserDefined.E = Math.E
+	var stack = [],
+		pop1,
+		pop2,
+		pop3
+	var disp = []
+	var temp = ''
+	var arr = this.value
+	var bool = typeof UserDefined.n !== 'undefined'
+	for (var i = 0; i < arr.length; i++) {
+		if (arr[i].type === 1) {
+			stack.push({ value: arr[i].value, type: 1 })
+		} else if (arr[i].type === 3) {
+			stack.push({ value: UserDefined[arr[i].value], type: 1 })
+		} else if (arr[i].type === 0) {
+			if (typeof stack[stack.length - 1].type === 'undefined') {
+				stack[stack.length - 1].value.push(arr[i])
+			} else stack[stack.length - 1].value = arr[i].value(stack[stack.length - 1].value)
+		} else if (arr[i].type === 7) {
+			if (typeof stack[stack.length - 1].type === 'undefined') {
+				stack[stack.length - 1].value.push(arr[i])
+			} else stack[stack.length - 1].value = arr[i].value(stack[stack.length - 1].value)
+		} else if (arr[i].type === 8) {
+			var popped = []
+			for (var x = 0; x < arr[i].numberOfArguments; x++) {
+				popped.push(stack.pop().value)
+			}
+			stack.push({ type: 1, value: arr[i].value.apply(arr[i], popped.reverse()) })
+		} else if (arr[i].type === 10) {
+			pop1 = stack.pop()
+			pop2 = stack.pop()
+			if (typeof pop2.type === 'undefined') {
+				pop2.value = pop2.concat(pop1)
+				pop2.value.push(arr[i])
+				stack.push(pop2)
+			} else if (typeof pop1.type === 'undefined') {
+				pop1.unshift(pop2)
+				pop1.push(arr[i])
+				stack.push(pop1)
+			} else {
+				stack.push({ type: 1, value: arr[i].value(pop2.value, pop1.value) })
+			}
+		} else if (arr[i].type === 2 || arr[i].type === 9) {
+			pop1 = stack.pop()
+			pop2 = stack.pop()
+			if (typeof pop2.type === 'undefined') {
+				pop2 = pop2.concat(pop1)
+				pop2.push(arr[i])
+				stack.push(pop2)
+			} else if (typeof pop1.type === 'undefined') {
+				pop1.unshift(pop2)
+				pop1.push(arr[i])
+				stack.push(pop1)
+			} else {
+				stack.push({ type: 1, value: arr[i].value(pop2.value, pop1.value) })
+			}
+		} else if (arr[i].type === 12) {
+			pop1 = stack.pop()
+			if (typeof pop1.type !== 'undefined') {
+				pop1 = [pop1]
+			}
+			pop2 = stack.pop()
+			pop3 = stack.pop()
+			stack.push({ type: 1, value: arr[i].value(pop3.value, pop2.value, new Mexp(pop1)) })
+		} else if (arr[i].type === 13) {
+			if (bool) {
+				stack.push({ value: UserDefined[arr[i].value], type: 3 })
+			} else stack.push([arr[i]])
+		}
+	}
+	if (stack.length > 1) {
+		throw new Mexp.Exception('Uncaught Syntax error')
+	}
+	return stack[0].value > 1000000000000000 ? 'Infinity' : parseFloat(stack[0].value.toFixed(15))
+}
+Mexp.eval = function (str, tokens, obj) {
+	if (typeof tokens === 'undefined') {
+		return this.lex(str).toPostfix().postfixEval()
+	} else if (typeof obj === 'undefined') {
+		if (typeof tokens.length !== 'undefined') return this.lex(str, tokens).toPostfix().postfixEval()
+		else return this.lex(str).toPostfix().postfixEval(tokens)
+	} else return this.lex(str, tokens).toPostfix().postfixEval(obj)
+}
+module.exports = Mexp