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Tooling

fibc run -O 0 uses fast development code generation; build defaults to -O 2. check MODULE.. checks every definition in named modules and dependencies; exit 0 means checked, 3 means rejected and 2 means unloadable. explain FILE shows ownership decisions. emit prints lIR; emit-dump is a compiler tool. serve retains front-end state over a Unix socket, --server sends requests with local fallback, and repl keeps definitions in a session (below). See the dev-loop record for protocol and limits. lsp serves editor requests over stdio; see VS Code setup. All flags are in the generated CLI reference. make help lists contributor targets. make adr invokes a standalone runner; there is no fibc adr command.

(defun main () -> i64 (do (println "hello from fibber") 0))

hello from fibber
0

The REPL

fibc repl [-I DIR].. is the quickest way to try an idea. Type a definition (defun, defrecord, defenum, defprotocol, defmacro, require, use and the rest) or one expression; an expression is compiled, run and its value printed.

$ fibc repl
fib> (defun sq (x: i64) -> i64 (* x x))
; defined sq
fib> (defun cube (x: i64) -> i64 (* x (sq x)))
; defined cube
fib> (cube 3)
27
fib> (defun sq (x: i64) -> str "no")
<session>:2:34: cannot unify str with i64 [type/Unify] (in the definition of cube)
; refused; the session is unchanged
  • A redefinition replaces the old one only if every definition that depends on it still checks; otherwise nothing changes and the message names the one that broke.
  • Ownership and type errors are reported as fibc check reports them. A trap ends only the evaluated program (; the program trapped (status 134); the session is unchanged).
  • A session is its source text. Each expression runs as a fresh program, so values (an atom, a def's result) do not persist from one input to the next.
  • Commands: :type EXPR, :doc NAME, :time EXPR, :load FILE, :reload, :defs, :reset, :help, :quit. On a terminal there is line editing and a history in ~/.fibc_history; ctrl-c stops a running program, not the session.
  • It is a development tool, not a second implementation of the language: a case's verdict comes from the compiled run (ADR 0005); the design is dev-loop §9.