Building in public.

first just got fn function literals, calls, and closures. I expected closures to need a capture list or a snapshot of variables. Instead they fell out of the Environment struct that was already backing every block.

JMap is a simple open-addressing hash map in about 120 lines of C. Here's why writing it myself was the right call, and what I learned about linear probing along the way.

Most toy lexer implementations slurp the whole source into a string buffer first. Here's why I went with a FILE*-based streaming approach and what get_while() and get_until() ended up looking like.

Adding a new AST node type in many C implementations means a new malloc, a new free, and an audit of every switch statement. Here's how first's tagged union design keeps that manageable.

Criterion is a great testing framework but its CMake integration has a few rough edges. This is the setup that actually worked, and the test patterns I wish I'd started with.

I didn't need a Pratt parser or a precedence table. Precedence fell out of the grammar structure for free — and understanding why is one of the most satisfying moments in building first.