package bos
Library
Module
Module type
Parameter
Class
Class type
include module type of struct include Fmt end
Standard outputs
val stdout : Format.formatter
stdout
is the standard output formatter.
val stderr : Format.formatter
stderr
is the standard error formatter.
Formatting
val pf : Format.formatter -> ('a, Format.formatter, unit) format -> 'a
pf
is Format.fprintf
.
val pr : ('a, Format.formatter, unit) format -> 'a
pr
is pf stdout
.
val epr : ('a, Format.formatter, unit) format -> 'a
epr
is pf stderr
.
val strf : ('a, Format.formatter, unit, string) format4 -> 'a
strf
is Format.asprintf
.
Note. When using strf
utf_8
and style_renderer
are always respectively set to true
and `None
. See also strf_like
.
val kpf :
(Format.formatter -> 'a) ->
Format.formatter ->
('b, Format.formatter, unit, 'a) format4 ->
'b
kpf
is Format.kfprintf
.
val kstrf : (string -> 'a) -> ('b, Format.formatter, unit, 'a) format4 -> 'b
kstrf
is like strf
but continuation based.
val strf_like :
Format.formatter ->
('a, Format.formatter, unit, string) format4 ->
'a
strf_like ppf
is like strf
except its utf_8
and style_renderer
settings are those of ppf
.
val with_buffer : ?like:Format.formatter -> Buffer.t -> Format.formatter
with_buffer ~like b
is a formatter whose utf_8
and style_renderer
settings are copied from those of like
(if provided).
Formatting exceptions
val failwith : ('a, Format.formatter, unit, 'b) format4 -> 'a
failwith
is kstrf failwith
, raises Stdlib.Failure
with a pretty-printed string argument.
val invalid_arg : ('a, Format.formatter, unit, 'b) format4 -> 'a
invalid_arg
is kstrf invalid_arg
, raises Stdlib.Invalid_argument
with a pretty-printed string argument.
Formatters
type 'a t = Format.formatter -> 'a -> unit
The type for formatters of values of type 'a
.
val nop : 'a t
nop
formats nothing.
val cut : unit t
cut
is Format.pp_print_cut
.
val sp : unit t
sp
is Format.pp_print_space
.
val unit : (unit, Format.formatter, unit) format -> unit t
unit fmt
formats a unit value with the format fmt
.
val fmt : ('a, Format.formatter, unit) format -> Format.formatter -> 'a
fmt fmt ppf
is pf ppf fmt
. If fmt
is used with a single non-constant formatting directive, generates a value of type t
.
val always : (unit, Format.formatter, unit) format -> 'a t
always fmt ppf v
formats any value with the constant format fmt
.
Base type formatters
val bool : bool t
bool
is Format.pp_print_bool
.
val int : int t
int
is pf ppf "%d"
.
val nativeint : nativeint t
nativeint ppf
is pf ppf "%nd"
.
val int32 : int32 t
int32 ppf
is pf ppf "%ld"
.
val int64 : int64 t
int64 ppf
is pf ppf "%Ld"
.
val uint : int t
uint ppf
is pf ppf "%u"
.
val unativeint : nativeint t
unativeint ppf
is pf ppf "%nu"
.
val uint32 : int32 t
uint32 ppf
is pf ppf "%lu"
.
val uint64 : int64 t
uint64 ppf
is pf ppf "%Lu"
.
val float : float t
float ppf
is pf ppf "%g".
val float_dfrac : int -> float t
float_dfrac d
rounds the float to the d
th decimal fractional digit and formats the result with "%g"
. Ties are rounded towards positive infinity. The result is only defined for 0 <= d <= 16
.
val float_dsig : int -> float t
float_dsig d
rounds the normalized decimal significand of the float to the d
th decimal fractional digit and formats the result with "%g"
. Ties are rounded towards positive infinity. The result is NaN on infinities and only defined for 0 <= d <= 16
.
Warning. The current implementation overflows on large d
and floats.
val char : char t
char
is Format.pp_print_char
.
val string : string t
string
is Format.pp_print_string
.
val exn : exn t
exn
formats an exception.
val exn_backtrace : (exn * Printexc.raw_backtrace) t
exn_backtrace
formats an exception backtrace.
Polymorphic type formatters
These formatters give full control to the client over the formatting process and do not wrap the formatted structures with boxes. Use the Dump
module to quickly format values for inspection.
pair ~sep pp_fst pp_snd
formats a pair. The first and second projection are formatted using pp_fst
and pp_snd
and are separated by sep
(defaults to cut
).
option ~none pp_v
formats an optional value. The Some
case uses pp_v
and None
uses none
(defaults to nop
).
result ~ok ~error
formats a result value using ok
for the Ok
case and error
for the Error
case.
hashtbl ~sep pp_binding
formats the bindings of a hash table. Each binding is formatted with pp_binding
and bindings are separated by sep
(defaults to cut
). If the hash table has multiple bindings for a given key, all bindings are formatted, with the most recent binding first. If the hash table is empty, this is nop
.
iter ~sep iter pp_elt
formats the iterations of iter
over a value using pp_elt
. Iterations are separated by sep
(defaults to cut
).
iter_bindings ~sep iter pp_binding
formats the iterations of iter
over a value using pp_binding
. Iterations are separated by sep
(defaults to cut
).
module Dump = Fmt.Dump
Formatters for inspecting OCaml values.
Boxes
box ~indent pp ppf
wraps pp
in a horizontal or vertical box. Break hints that lead to a new line add indent
to the current indentation (defaults to 0
).
hbox
is like box
but is a horizontal box: the line is not split in this box (but may be in sub-boxes).
vbox
is like box
but is a vertical box: every break hint leads to a new line which adds indent
to the current indentation (default to 0
).
Brackets
quote ~mark pp_v ppf
is pf "@[<1>@<1>%s%a@<1>%s@]" mark pp_v mark
, mark
defaults to "\""
, it is always counted as spanning as single column (this allows for UTF-8 encoded marks).
Words, paragraphs, text and lines
Note. These functions only work on US-ASCII strings and/or with newlines ('\n'
). If you are dealing with UTF-8 strings or different kinds of line endings you should use the pretty-printers from Uuseg_string
.
White space. White space is one of the following US-ASCII characters: space ' '
(0x20
), tab '\t'
(0x09
), newline '\n'
(0x0A
), vertical tab (0x0B
), form feed (0x0C
), carriage return '\r'
(0x0D
).
val words : string t
words
formats words by suppressing initial and trailing white space and replacing consecutive white space with a single Format.pp_print_space
.
val paragraphs : string t
paragraphs
formats paragraphs by suppressing initial and trailing spaces and newlines, replacing blank lines (a line made only of white space) by a two Format.pp_force_newline
and remaining consecutive white space with a single Format.pp_print_space
.
val text : string t
text
formats text by respectively replacing spaces and newlines in the string with Format.pp_print_space
and Format.pp_force_newline
.
val lines : string t
lines
formats lines by replacing newlines ('\n'
) in the string with calls to Format.pp_force_newline
.
val text_loc : ((int * int) * (int * int)) t
text_loc
formats a line-column text range according to GNU conventions.
Appending
append pp_v0 pp_v1 ppf (v0, v1)
is pp_v0 ppf v0; pp_v1 ppf v1
.
Byte sizes
val byte_size : int t
byte_size
formats a byte size according to its magnitude using SI prefixes up to peta bytes (1015).
val bi_byte_size : int t
bi_byte_size
formats a byte size according to its magnitude using binary prefixes up to pebi bytes (215).
Conditional UTF-8 formatting
Note. Since Format
is not UTF-8 aware using UTF-8 output may derail the pretty printing process. Use the pretty-printers from Uuseg_string
if you are serious about UTF-8 formatting.
if_utf_8 pp_u pp ppf v
is:
pp_u ppf v
ifutf_8 ppf
istrue
.pp ppf v
otherwise.
val utf_8 : Format.formatter -> bool
utf_8 ppf
is true
if UTF-8 output is enabled on ppf
. If set_utf_8
hasn't been called on ppf
this is true
.
val set_utf_8 : Format.formatter -> bool -> unit
set_utf_8 ppf b
enables or disables conditional UTF-8 formatting on ppf
.
Warning. Using this function replaces any Format.tag
functions that may be in place.
Styled formatting
val styled_unit : style -> (unit, Format.formatter, unit) format -> unit t
styled_unit s fmt
is style s (unit fmt)
.
Style rendering control
The type for style renderers.
`Ansi_tty
, renders styles using ANSI escape sequences.`None
, styled rendering has no effect.
val style_renderer : Format.formatter -> style_renderer
style_renderer ppf
is the style renderer used by ppf
. If set_style_renderer
has never been called on ppf
this is `None
.
val set_style_renderer : Format.formatter -> style_renderer -> unit
set_style_renderer ppf r
sets the style renderer of ppf
to r
.
Warning. Using this function replaces any Format.tag
functions that may be in place.
Converting with string value converters
val of_to_string : ('a -> string) -> 'a t
of_to_string f ppf v
is string ppf (f v)
.
val to_to_string : 'a t -> 'a -> string
to_to_string pp_v v
is strf "%a" pp_v v
.
Naming conventions
Given a type ty
use:
pp_ty
for a pretty printer that provides full control to the client and does not wrap the formatted value in an enclosing box. See these examples.dump_ty
for a pretty printer that provides little control over the pretty-printing process, wraps the rendering in an enclosing box and tries as much as possible to respect the OCaml syntax. These pretty-printers should make it easy to inspect and understand values of the given type, they are mainly used for quick printf debugging and/or toplevel interaction. See these examples.
If you are in a situation where making a difference between dump_ty
and pp_ty
doesn't make sense then use pp_ty
.
For a type ty
that is the main type of the module (the "M.t
" convention) drop the suffix, that is simply use M.pp
and M.dump
.