lexer

This term is highly specialized technical jargon used almost exclusively within computer science, specifically in the fields of compiler design and formal language theory. It describes the first stage of a compiler's front end, where raw source code is broken down into meaningful units called tokens. It is often used interchangeably with the term scanner, though some academic contexts distinguish between the two based on whether the component merely scans characters or actively produces tokens.

Because it refers to a specific software component, it is used in a neutral, descriptive register. It typically appears in technical documentation, academic textbooks on programming languages, and discussions regarding the architecture of interpreters or compilers.