package containers

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Helpers for Format

  • since 0.8
type 'a sequence = ('a -> unit) -> unit
type 'a printer = t -> 'a -> unit

Combinators

val silent : 'a printer

Prints nothing

val unit : unit printer

Prints "()"

val int : int printer
val string : string printer
val bool : bool printer
val float3 : float printer
val float : float printer
val newline : unit printer

Force newline (see Format.pp_force_newline)

  • since 1.2
val substring : (string * int * int) printer

Print the substring (s,i,len), where i is the offset in s and len the number of bytes in the substring.

  • raises Invalid_argument

    if the triple (s,i,len) does not describe a proper substring.

  • since 1.2
val text : string printer

Print string, but replacing spaces with breaks and newlines with newline. See pp_print_text on recent versions of OCaml.

  • since 1.2
val char : char printer
  • since 0.14
val int32 : int32 printer
  • since 0.14
  • since 0.14
val int64 : int64 printer
  • since 0.14
  • since 0.14
val nativeint : nativeint printer
  • since 0.14
  • since 0.14
val flush : unit printer

Alias to Format.pp_print_flush.

  • since 1.2
val string_quoted : string printer

Similar to CCString.print.

  • since 0.14
val list : ?sep:unit printer -> 'a printer -> 'a list printer
val array : ?sep:unit printer -> 'a printer -> 'a array printer
val arrayi : ?sep:unit printer -> (int * 'a) printer -> 'a array printer
val seq : ?sep:unit printer -> 'a printer -> 'a sequence printer
val opt : 'a printer -> 'a option printer

opt pp prints options as follows: Some x will become "some foo" if pp x ---> "foo" None will become "none"

In the tuple printers, the sep argument is only available

  • since 0.17
val pair : ?sep:unit printer -> 'a printer -> 'b printer -> ('a * 'b) printer
val triple : ?sep:unit printer -> 'a printer -> 'b printer -> 'c printer -> ('a * 'b * 'c) printer
val quad : ?sep:unit printer -> 'a printer -> 'b printer -> 'c printer -> 'd printer -> ('a * 'b * 'c * 'd) printer
val within : string -> string -> 'a printer -> 'a printer

within a b p wraps p inside the strings a and b. Convenient, for instances, for brackets, parenthesis, quotes, etc.

  • since 0.17
val map : ('a -> 'b) -> 'b printer -> 'a printer
val vbox : ?i:int -> 'a printer -> 'a printer

Wrap the printer in a vertical box

  • parameter i

    level of indentation within the box (default 0)

  • since 0.16
val hvbox : ?i:int -> 'a printer -> 'a printer

Wrap the printer in a horizontal/vertical box

  • parameter i

    level of indentation within the box (default 0)

  • since 0.16
val hovbox : ?i:int -> 'a printer -> 'a printer

Wrap the printer in a horizontal or vertical box

  • parameter i

    level of indentation within the box (default 0)

  • since 0.16
val hbox : 'a printer -> 'a printer

Wrap the printer in an horizontal box

  • since 0.16
val return : ('a, _, _, 'a) format4 -> unit printer

return "some_format_string" takes a argument-less format string and returns a printer actionable by (). Examples:

  • return ",@ "
  • return "@{<Red>and then@}@,"
  • return "@[<v>a@ b@]"
  • since 1.0
val of_to_string : ('a -> string) -> 'a printer

of_to_string f converts its input to a string using f, then prints the string

  • since 1.0
val const : 'a printer -> 'a -> unit printer

const pp x is a unit printer that uses pp on x

  • since 1.0
val some : 'a printer -> 'a option printer

some pp will print options as follows:

  • Some x is printed using pp on x
  • None is not printed at all
  • since 1.0

ANSI codes

Use ANSI escape codes https://en.wikipedia.org/wiki/ANSI_escape_code to put some colors on the terminal.

This uses tags in format strings to specify the style. Current styles are the following:

  • "reset" resets style
  • "black"
  • "red"
  • "green"
  • "yellow"
  • "blue"
  • "magenta"
  • "cyan"
  • "white"
  • "bold" bold font
  • "Black" bold black
  • "Red" bold red
  • "Green" bold green
  • "Yellow" bold yellow
  • "Blue" bold blue
  • "Magenta" bold magenta
  • "Cyan" bold cyan
  • "White" bold white

Example:

set_color_default true;;

Format.printf
  "what is your @{<White>favorite color@}? @{<blue>blue@}! No, @{<red>red@}! Ahhhhhhh@.";;

status: experimental

  • since 0.15
val set_color_tag_handling : t -> unit

adds functions to support color tags to the given formatter.

  • since 0.15
val set_color_default : bool -> unit

set_color_default b enables color handling on the standard formatters (stdout, stderr) if b = true as well as on sprintf formatters; it disables the color handling if b = false.

val with_color : string -> 'a printer -> 'a printer

with_color "Blue" pp behaves like the printer pp, but with the given style. status: experimental

  • since 0.16
val with_colorf : string -> t -> ('a, t, unit, unit) format4 -> 'a

with_colorf "Blue" out "%s %d" "yolo" 42 will behave like Format.fprintf, but wrapping the content with the given style status: experimental

  • since 0.16
val with_color_sf : string -> ('a, t, unit, string) format4 -> 'a

with_color_sf "Blue" out "%s %d" "yolo" 42 will behave like sprintf, but wrapping the content with the given style Example:

CCFormat.with_color_sf "red" "%a" CCFormat.Dump.(list int) [1;2;3] |> print_endline;;

status: experimental

  • since 0.21
val with_color_ksf : f:(string -> 'b) -> string -> ('a, t, unit, 'b) format4 -> 'a

with_color_ksf "Blue" ~f "%s %d" "yolo" 42 will behave like ksprintf, but wrapping the content with the given style Example: the following with raise Failure with a colored message

CCFormat.with_color_ksf "red" ~f:failwith "%a" CCFormat.Dump.(list int) [1;2;3];;
  • since 1.2

IO

val output : t -> 'a printer -> 'a -> unit
val to_string : 'a printer -> 'a -> string
val of_chan : out_channel -> t
val with_out_chan : out_channel -> (t -> 'a) -> 'a

with_out_chan oc f turns oc into a formatter fmt, and call f fmt. Behaves like f fmt from then on, but whether the call to f fails or returns, fmt is flushed before the call terminates.

  • since 1.2
val stdout : t
val stderr : t
val tee : t -> t -> t

tee a b makes a new formatter that writes in both a and b.

  • since 1.0
val sprintf : ('a, t, unit, string) format4 -> 'a

Print into a string any format string that would usually be compatible with fprintf. Similar to Format.asprintf.

val sprintf_no_color : ('a, t, unit, string) format4 -> 'a

Similar to sprintf but never prints colors

  • since 0.16
val sprintf_dyn_color : colors:bool -> ('a, t, unit, string) format4 -> 'a

Similar to sprintf but enable/disable colors depending on colors. Example:

(* with colors *)
CCFormat.sprintf_dyn_color ~colors:true "@{<Red>%a@}"
  CCFormat.Dump.(list int) [1;2;3] |> print_endline;;

(* without colors *)
CCFormat.sprintf_dyn_color ~colors:false "@{<Red>%a@}"
  CCFormat.Dump.(list int) [1;2;3] |> print_endline;;
  • since 0.21
val fprintf : t -> ('a, t, unit) format -> 'a

Alias to Format.fprintf

  • since 0.14
val fprintf_dyn_color : colors:bool -> t -> ('a, t, unit) format -> 'a

Similar to fprintf but enable/disable colors depending on colors

  • since 0.21
val ksprintf : f:(string -> 'b) -> ('a, Format.formatter, unit, 'b) format4 -> 'a

ksprintf fmt ~f formats using fmt, in a way similar to sprintf, and then calls f on the resulting string.

  • since 0.14
val to_file : string -> ('a, t, unit, unit) format4 -> 'a

Print to the given file

Dump

Print structures as OCaml values, so that they can be parsed back by OCaml (typically, in the toplevel, for debugging).

Example:

Format.printf "%a@." CCFormat.Dump.(list int) CCList.(1 -- 200);;

Format.printf "%a@." CCFormat.Dump.(array (list (pair int bool)))
  [| [1, true; 2, false]; []; [42, false] |];;
  • since 0.21
module Dump : sig ... end
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