Show HN: Building a C Lexer from Scratch

A developer going by johnryzon123 posted a Show HN on August 25, 2026 sharing Ciyac, a lexer and scanner built from scratch using the C programming language, and published to GitHub under the Iya-lang organization.

The project is described by the author as "as basic as 123" — a minimal, ground-up implementation of a lexer, which is the first stage of a compiler or interpreter responsible for tokenizing source code into meaningful symbols. According to the HN post, the author is actively seeking feedback from the community, with the submission drawing one comment at the time of publication.

A lexer — also called a scanner — reads raw source text and breaks it into tokens such as keywords, identifiers, operators, and literals. Writing one in C, close to the metal without relying on generator tools like Flex or ANTLR, is a common early step for developers exploring programming language implementation. The GitHub repository is hosted under the Iya-lang organization, suggesting the lexer may be intended as a component of a broader language project, though no further details about that language are provided in the source.

No funding, team size, or organizational background is mentioned in the submission. The project appears to be an individual or small open-source effort at an early stage, with the author explicitly framing it as a work in progress and inviting critique rather than announcing a finished tool.

Those interested in following development or leaving feedback can find the project at the Ciyac GitHub repository or in the original HN thread.