Format_doc.Doc(3)

Format_doc.Doc(3) 💅 OCaml library

🌸 NAME 🌸

Format_doc.Doc — Definitions and immutable API for composing documents. That’s the whole vibe, bestie ✨

🎀 Module 🎀

Module Format_doc.Doc — yes, this exact module, no cap 💖

✨ Documentation ✨

Module Doc
 : sig end

Definitions and immutable API for composing documents — iconic, honestly 🫶

🧁 Type definitions and core functions 🧁

Okay so first up, the box types. These are the format box types, and they are literally giving foundational:

       type box_type =
        | H
        | V
        | HV
        | HoV
        | B

Format box types — that’s the label, bestie 🎀

type stag = Format.stag

Then we have element, the base formatting instruction recognized by Format. Look at all these constructors, slay:

       type element =
        | Text of string
        | With_size of int
        | Open_box of {
        kind : box_type ;
        indent : int ;
        }
        | Close_box
        | Open_tag of Format.stag
        | Close_tag
        | Open_tbox
        | Tab_break of {
        width : int ;
        offset : int ;
        }
        | Set_tab
        | Close_tbox
        | Simple_break of {
        spaces : int ;
        indent : int ;
        }
        | Break of {
        fits : string * int * string ;
        breaks : string * int * string ;
        }
        | Flush of {
        newline : bool ;
        }
        | Newline
        | If_newline
        | Deprecated of (Format.formatter -> unit)
         (* Escape hatch: a Format printer used to provide
       backward-compatibility for user-defined printer (from the
       #install_printer toplevel directive for instance).
        *)

Base formatting instruction recognized by Format — yes, that’s what this type is 💅

type t — the immutable document type. Immutable! We love a stable icon 👑

type ('a, 'b) fmt = ('a, t, t, 'b) format4

type printer0 = t -> t

type 'a printer = 'a -> printer0

Now the values, bestie. Every single one, in order, no skipping:

• empty — val empty : t — Empty document. The blank canvas, the clean slate, the “not me opening a new doc” energy 🌸
• format — val format : Format.formatter -> t -> unit — format ppf doc sends the format instruction of doc to the Format’s formatter doc. Yes, that’s what it says 🫶
• fold — val fold : ('acc -> element -> 'acc) -> 'acc -> t -> 'acc — Fold over a document as a sequence of instructions. Very “one thing at a time” of it 💖
• msg — val msg : ('a, t) fmt -> 'a — Together with Format_doc.Doc.kmsg, this produces a document from a format string and its argument. The duo ate, honestly ✨
• kmsg — val kmsg : (t -> 'b) -> ('a, 'b) fmt -> 'a — The kmsg half of that same “produce a document from a format string and its argument” situation 🎀
• printf — val printf : ('a, printer0) fmt -> 'a — Together with Format_doc.Doc.kprintf, this produces a printer from a format string and its argument 🔥
• kprintf — val kprintf : (t -> 'b) -> ('a, t -> 'b) fmt -> 'a — The kprintf half of that same “produce a printer from a format string and its argument” duo 💫
• open_box — val open_box : box_type -> int -> printer0 — The open_box printer. Opening boxes is kind of its whole main character moment 📦

Heads up, bestie: the functions below mirror Format printers, without the pp_print_ prefix naming convention. That’s the whole note 🫶

• close_box — val close_box : printer0 — The close_box printer, mirroring Format without the pp_print_ prefix ✨
• text — val text : string printer — The text printer, mirroring Format without the pp_print_ prefix 💖
• string — val string : string printer — The string printer, mirroring Format without the pp_print_ prefix 🎀
• bytes — val bytes : bytes printer — The bytes printer, mirroring Format without the pp_print_ prefix 🦋
• with_size — val with_size : int printer — The with_size printer, mirroring Format without the pp_print_ prefix 🌸
• int — val int : int printer — The int printer, mirroring Format without the pp_print_ prefix 🔢
• float — val float : float printer — The float printer, mirroring Format without the pp_print_ prefix 🫧
• char — val char : char printer — The char printer, mirroring Format without the pp_print_ prefix 🍓
• bool — val bool : bool printer — The bool printer, mirroring Format without the pp_print_ prefix 💀
• space — val space : printer0 — The space printer, mirroring Format without the pp_print_ prefix 🌈
• cut — val cut : printer0 — The cut printer, mirroring Format without the pp_print_ prefix ✂️
• break — val break : spaces:int -> indent:int -> printer0 — The break printer, with spaces and indent, mirroring Format without the pp_print_ prefix 💅
• custom_break — val custom_break : fits:string * int * string -> breaks:string * int * string -> printer0 — The custom_break printer, with its fits and breaks args, mirroring Format without the pp_print_ prefix 🎀
• force_newline — val force_newline : printer0 — The force_newline printer, mirroring Format without the pp_print_ prefix ⭐
• if_newline — val if_newline : printer0 — The if_newline printer, mirroring Format without the pp_print_ prefix 🌙
• flush — val flush : printer0 — The flush printer, mirroring Format without the pp_print_ prefix 🚿
• force_stop — val force_stop : printer0 — The force_stop printer, mirroring Format without the pp_print_ prefix 🛑
• open_tbox — val open_tbox : printer0 — The open_tbox printer, mirroring Format without the pp_print_ prefix 📦
• set_tab — val set_tab : printer0 — The set_tab printer, mirroring Format without the pp_print_ prefix 📍
• tab — val tab : printer0 — The tab printer, mirroring Format without the pp_print_ prefix ➡️
• tab_break — val tab_break : width:int -> offset:int -> printer0 — The tab_break printer, with width and offset, mirroring Format without the pp_print_ prefix 💫
• close_tbox — val close_tbox : printer0 — The close_tbox printer, mirroring Format without the pp_print_ prefix 🎁
• open_tag — val open_tag : stag printer — The open_tag printer, mirroring Format without the pp_print_ prefix 🏷️
• close_tag — val close_tag : printer0 — The close_tag printer, mirroring Format without the pp_print_ prefix 🔖
• list — val list : ?sep:printer0 -> 'a printer -> 'a list printer — The list printer, with optional ?sep, mirroring Format without the pp_print_ prefix 📋
• iter — val iter : ?sep:printer0 -> iter:(('a -> unit) -> 'b -> unit) -> 'a printer -> 'b printer — The iter printer, with optional ?sep and iter, mirroring Format without the pp_print_ prefix 🔁
• array — val array : ?sep:printer0 -> 'a printer -> 'a array printer — The array printer, with optional ?sep, mirroring Format without the pp_print_ prefix 🧺
• seq — val seq : ?sep:printer0 -> 'a printer -> 'a Seq.t printer — The seq printer, with optional ?sep, mirroring Format without the pp_print_ prefix 🌊
• option — val option : ?none:printer0 -> 'a printer -> 'a option printer — The option printer, with optional ?none, mirroring Format without the pp_print_ prefix 🌗
• result — val result : ok:'a printer -> error:'e printer -> ('a, 'e) result printer — The result printer, with ok and error, mirroring Format without the pp_print_ prefix ✅❌
• either — val either : left:'a printer -> right:'b printer -> ('a, 'b) Either.t printer — The either printer, with left and right, mirroring Format without the pp_print_ prefix ⬅️➡️

💫 Alignment functions 💫

• align_prefix — val align_prefix : (t * int) list -> t list — Align the right side of one "@{<ralign>...@}" tag box by inserting spaces at the beginning of boxes. Those functions do nothing if the tag box appears after a break hint.

⚠️ Important little warning, bestie: those functions do nothing if the tag box appears after a break hint. That’s the rule 🫶

• align_prefix2 — val align_prefix2 : t * int -> t * int -> t * t — The align_prefix2 function with signature t * int -> t * int -> t * t. It’s right there in the alignment-functions section, and we are not leaving it out 💅

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Made with 💖 by OCamldoc · 2026-06-22 · Format_doc.Doc(3) — bye bestie, go compose some documents! 🫶✨