Joseph Ferano
19be614f22
The type-directed half — (read-edn Enemy bytes), a parser emitted from a compile-time walk over a struct — is the compiler's work and is not here. What a running program can have today is the half underneath it, and the shape of that half is decided entirely by there being no heap: a token is a slice of the input, so reading a file costs one buffer and nothing else, and the cost is a lifetime contract the types cannot state. It is stated in the header instead, because a dangling [u8] is otherwise found from a corrupted string several frames later. A package and not the prelude. The prelude is prepended to every program and everything in it is emitted, so a reader nobody imports would be a tax on every build. Token kinds are i32 constants rather than a defenum, which reads like a downgrade and is not one: an Enum value cannot be compared with `=` (emit fails) and a keyword is not a pattern (`match` refuses one), so a defenum here is FFI-only and a caller could not branch on a kind at all. Both fixes live in check.ml and emit.ml, which this lane does not touch. Errors land on the cursor — a code and a byte offset — rather than in an (Option Token). None says something went wrong; an editor needs to know where, and a second out-parameter for the position is the same two fields with a worse shape. A failed cursor is poisoned so a caller's while loop stops instead of spinning. error-message turns a code into the sentence, and every refusal gets its own: escapes, sets, tagged literals, #inst and #uuid separately, metadata, ratios and characters each name themselves and say why, so a file using one fails with what to remove rather than with a number. Escapes are the refusal that had to be a refusal. Unescaping needs somewhere to put the copy and there is nowhere; returning the raw bytes would hand back a three-byte string as four, with a backslash in it, and nothing would say so. Balance is checked in `next` against a fixed [32 i32] stack in the cursor, because `[1 2}` is malformed in a way only the tokenizer has the position for, and a growable stack is another thing there is no allocator for. Past 32 the answer is err-too-deep rather than a closer that quietly went unchecked. Symbol starts are a list and not "anything that is not a delimiter". Without that, `@` and a backtick read as one-character symbols instead of being reported; the ratio test is likewise digit-started only, so foo/bar stays a namespaced symbol.
