Tooling
Alpaca's macros already compute everything there is to know about your grammar at compile time — the token patterns, the productions, the resolved LR table. Two environment variables let you pull that information out, for two different audiences:
| Variable | Writes | For |
|---|---|---|
ALPACA_DEBUG_DIR |
The constructed parse tables, action table, and conflict-resolution table | You, to understand or debug a grammar |
ALPACA_GRAMMAR_EXPORT_DIR |
The grammar's shape (tokens, productions, table) as JSON | Tools that consume grammars, chiefly the IntelliJ plugin |
Both are read from the environment at macro-expansion time, do nothing when unset, and have no runtime cost or effect on the compiled artifact. Both work with any build tool that runs the Scala 3 compiler — the linked pages show Mill, sbt, and Scala CLI.
- Debug Settings — dump the LR automaton and conflict-resolution tables to disk during compilation, to see why a grammar has a conflict or what automaton Alpaca built.
- IntelliJ Plugin — turn any Alpaca-defined language into a real custom language in the IDE, with syntax highlighting, real parsing, autocompletion, structure view, and code folding — no per-language plugin code.
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