;; lib/flow/api.sx — flow runtime entry points.
;;
;; Builds a Scheme env preloaded with the flow combinators (lib/flow/spec.sx)
;; plus the public flow API, and provides SX helpers to run flow programs.
;;
;; Scheme-level API (available inside flow programs):
;;   (flow/start flow input) — run a flow with the given input, return result
;;
;; SX-level helpers (for hosts and tests):
;;   (flow-make-env)        — fresh standard env + combinators + api
;;   (flow-run src)         — eval a Scheme program string in a fresh flow env
;;   (flow-run-in env src)  — eval a Scheme program string in a given env

(define flow-api-src "(define (flow/start flow input) (flow input))")

(define
  flow-make-env
  (fn
    ()
    (let
      ((env (scheme-standard-env)))
      (flow-load-combinators! env)
      (scheme-eval-program (scheme-parse-all flow-api-src) env)
      env)))

(define
  flow-run-in
  (fn (env src) (scheme-eval-program (scheme-parse-all src) env)))

(define flow-run (fn (src) (flow-run-in (flow-make-env) src)))