How to read functions from a string using regex from commands in Java or What are the alternative op-CodePudding

I want to give commands using function like structure in string. For example I have three functions:

go() do() hello()

but also these function have bodies that also could contain the same functions.

"go(){do(){go}} do()"

These functions can also use parameters. How can I do this in regex. It is like creating a programming language.

CodePudding user response：

If you want to parse recursive languages with undefined recursion depth you can't use regex that only parses regular languages and is implemented using a Deterministic Finite Automaton.

Use a parser generator like ANTLR instead that suppurts non-regular grammars. It includes grammar files for all kinds of existing programming languages that you can use as example for parsing your own language.

CodePudding user response：

As per my understanding, We are having function calls as a string inside the function. If Yes, we can give a try to this RegEx.

\w \([^\)]*\)

\w : matches word characters. i.e. a-z, A-Z, 0-9, including _ (underscore).

: matches one or more occurrences of the word characters.

\( : matches opening round bracket

[^\)]* : matches zero or more characters except / and )

\) : matches closing round bracket

Live Demo (Just for a demo purpose I am using JavaScript, You can make the changes as per the Java) :

const str = "go(){do(){go}} do()";

console.log(str.match(/\w \([^\)]*\)/g)); // ["go()", "do()", "do()"]