To understand the internal principles and working mechanisms of the MXPARSER framework

MXPARSER is a Java framework for mathematical expression analysis and solution.It provides a fast, flexible and reliable parser that can analyze and calculate various mathematical expressions, including the four basic operations, function calls, variable processing, etc. The internal principles and working mechanisms of the MXPARSER framework are based on Context-FREE GRAMAR.In the process of expression analysis, MXPARSER first transformed the input mathematical expression into a syntax tree, and then solved it through the grammar tree.The internal principles and working mechanisms of the MXPARSER framework will be introduced in detail below. 1. Lexical Analysis: MXPARSER first analyzed the input mathematical expression, and split the expression into a symbol and identifier.Symbols can be operators, brackets, comma, etc., and the identifier can be numbers, variable names, function names, etc.MXPARSER uses FINITE Automaton to achieve phrase analysis and identify and classify symbols according to the predefined rules. 2. Syntax Analysis: After the lexical analysis, MXPARSER will analyze grammatical analysis based on a series of formulas and rules, and organize the symbol generated by the analysis of the phrase into a grammar tree in accordance with the grammatical rules.The grammar tree is a tree -shaped data structure, each of which represents an operator or number of operations.MXPARSER uses recursive decline analysis to build grammatical trees. 3. Semantic Analysis: After grammatical analysis, MXPARSER will analyze semantic tree semantic trees, verify the legality of expression and the definition and use of identifiers.It checks information related to semantics such as the assignment situation of the variable and whether the function of the function is matched.If there is a semantic error in the expression, MXPARSER will report an error message. 4. Expression Evaluation: After the semantic analysis is passed, MXPARSER will begin to perform expression solutions.MXPARSER traverses the grammar tree and calculates each operation in the expression based on the priority and binding of the operator.It uses stacks (stack) to store operators and operating numbers, and is calculated based on the priority and binding of the operator.MXPARSER supports a variety of basic operators and common functions, and can expand the custom function as needed. Below is a simple example code that demonstrates how to use the MXPARSER framework to analyze and calculate a mathematical expression: import org.mariuszgromada.math.mxparser.*; public class MxParserExample { public static void main(String[] args) { Expression expression = new Expression("3 + 4 * (2 - 1)"); double result = expression.calculate(); System.out.println ("Result:" + Result); } } In the above code, we created an Expression object and passed a mathematical expression as a parameter.We then call the Calculating () method to calculate the result of the expression and print the result. In summary, the MXPARSER framework analyzes and verify the legitimacy of mathematical expression through phylics analysis, grammar analysis, and semantic analysis, and then uses stacks and computing symbol priority to solve the expression.It is a powerful and easy -to -use mathematical expression solution framework, which can meet the mathematical computing needs in different scenarios.