wtf is lex?

The lex repository is a small Go library that helps programmers build lexers. A lexer is the piece of software that takes raw text and breaks it into meaningful chunks or tokens, like recognizing that "123" is a number or "if" is a keyword. This is typically one of the first steps in building tools that read and understand text, such as programming language compilers or configuration file parsers. In practical terms, you write code that uses this library to scan through a string of text character by character. As it reads, it groups those characters into categorized tokens that your program can then work with. The library provides the underlying plumbing for that scanning process so you can focus on defining what the tokens look like rather than worrying about the mechanics of walking through a string. Someone building a new programming language, a custom markup format, or a tool that reads structured data would use this. For example, if you were creating your own spreadsheet formula language and needed to distinguish between function names, cell references, operators, and literals, a lexer built with this library would handle that initial sorting step before another part of your program tries to understand the meaning behind the formulas. The README is quite sparse and does not go into detail about specific features, performance characteristics, or how the library compares to other approaches in the Go ecosystem. It is essentially a single line describing the project's purpose. What is notable is its simplicity and focus. Rather than being a full parser generator that handles both tokenizing and grammar rules, this is narrowly scoped to just the lexing stage. That makes it a lightweight building block for someone who wants to assemble their own text-processing toolchain piece by piece in Go.