package core_kernel

  1. Overview
  2. Docs
package core_kernel
Legend:
Library
Module
Module type
Parameter
Class
Class type

This module extends Base.Printf.

include module type of struct include Base.Printf end
val ifprintf : 'a -> ('r, 'a, 'c, unit) Pervasives.format4 -> 'r
val sprintf : ('r, unit, string) Pervasives.format -> 'r
val bprintf : Caml.Buffer.t -> ('r, Caml.Buffer.t, unit) Pervasives.format -> 'r
val ksprintf : (string -> 'a) -> ('r, unit, string, 'a) Pervasives.format4 -> 'r
val kbprintf : (Caml.Buffer.t -> 'a) -> Caml.Buffer.t -> ('r, Caml.Buffer.t, unit, 'a) Pervasives.format4 -> 'r
Formatting error and exit functions

These functions have polymorphic return type, since they do not return. Naively, this doesn't mix well with variadic functions: if you define, say,

let f fmt = ksprintf (fun s -> failwith s) fmt

then you find that f "%d" : int -> 'a, as you'd expect, and f "%d" 7 : 'a. The problem with this is that 'a unifies with (say) int -> 'b, so f "%d" 7 4 is not a type error -- the 4 is simply ignored.

To mitigate this problem, these functions all take a final unit parameter. These rarely arise as formatting positional parameters (they can do with e.g. "%a", but not in a useful way) so they serve as an effective signpost for "end of formatting arguments".

val failwithf : ('r, unit, string, unit -> _) Pervasives.format4 -> 'r

raises Failure

val invalid_argf : ('r, unit, string, unit -> _) Pervasives.format4 -> 'r

raises Invalid_arg

val eprintf : ('a, Stdio.Out_channel.t, unit) Pervasives.format -> 'a
val fprintf : Stdio.Out_channel.t -> ('a, Stdio.Out_channel.t, unit) Pervasives.format -> 'a
val kfprintf : (Stdio.Out_channel.t -> 'a) -> Stdio.Out_channel.t -> ('b, Stdio.Out_channel.t, unit, 'a) Pervasives.format4 -> 'b
val printf : ('a, Stdio.Out_channel.t, unit) Pervasives.format -> 'a
val exitf : ('a, unit, string, unit -> 'b) Pervasives.format4 -> 'a

print to stderr; exit 1

OCaml

Innovation. Community. Security.

GitHub Discord Twitter Peertube RSS
About
Changelog Releases Industrial Users Academic Users Why OCaml
Ecosystem
Packages Community Events OCaml Planet Jobs
Resources
Install OCaml Get Started Platform Tools Language Manual Standard Library API Books Exercises Papers OCaml Playground Logo
Policies
Carbon Footprint Governance Privacy Code of Conduct