The eval command

eval <expr> evaluates a closed IML expression and reports its value. It is the quickest way to sanity-check that a function computes what you expect while building up IML code — the equivalent of typing an expression at a REPL.

let rec fib (n:int) : int =
  if n <= 1 then n else fib (n-1) + fib (n-2)
 
eval fib 10          (* 55 *)
eval List.rev [1;2;3] (* [3;2;1] *)
eval (1, true, [4;5]) (* (1, true, [4;5]) *)
eval "hello" ^ " world" (* "hello world" *)

• eval takes an expression, not a binding (unlike let)
• CodeLogician CLI's check subcommand reports one result per eval, in source order, under eval_result_1, eval_result_2, ... with the value in the value_as_ocaml field.
  • Note that eval <expr> as a syntaxic structure has no direct relation with "eval" in codelogician eval ....