/usr/lib/ocaml/format.mli is in ocaml-nox 4.01.0-3ubuntu3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 | (***********************************************************************)
(* *)
(* OCaml *)
(* *)
(* Pierre Weis, projet Cristal, INRIA Rocquencourt *)
(* *)
(* Copyright 1996 Institut National de Recherche en Informatique et *)
(* en Automatique. All rights reserved. This file is distributed *)
(* under the terms of the GNU Library General Public License, with *)
(* the special exception on linking described in file ../LICENSE. *)
(* *)
(***********************************************************************)
(** Pretty printing.
This module implements a pretty-printing facility to format text
within 'pretty-printing boxes'. The pretty-printer breaks lines
at specified break hints, and indents lines according to the box
structure.
For a gentle introduction to the basics of pretty-printing using
[Format], read
{{:http://caml.inria.fr/resources/doc/guides/format.en.html}
http://caml.inria.fr/resources/doc/guides/format.en.html}.
You may consider this module as providing an extension to the
[printf] facility to provide automatic line breaking. The addition of
pretty-printing annotations to your regular [printf] formats gives you
fancy indentation and line breaks.
Pretty-printing annotations are described below in the documentation of
the function {!Format.fprintf}.
You may also use the explicit box management and printing functions
provided by this module. This style is more basic but more verbose
than the [fprintf] concise formats.
For instance, the sequence
[open_box 0; print_string "x ="; print_space ();
print_int 1; close_box (); print_newline ()]
that prints [x = 1] within a pretty-printing box, can be
abbreviated as [printf "@[%s@ %i@]@." "x =" 1], or even shorter
[printf "@[x =@ %i@]@." 1].
Rule of thumb for casual users of this library:
- use simple boxes (as obtained by [open_box 0]);
- use simple break hints (as obtained by [print_cut ()] that outputs a
simple break hint, or by [print_space ()] that outputs a space
indicating a break hint);
- once a box is opened, display its material with basic printing
functions (e. g. [print_int] and [print_string]);
- when the material for a box has been printed, call [close_box ()] to
close the box;
- at the end of your routine, flush the pretty-printer to display all the
remaining material, e.g. evaluate [print_newline ()].
The behaviour of pretty-printing commands is unspecified
if there is no opened pretty-printing box. Each box opened via
one of the [open_] functions below must be closed using [close_box]
for proper formatting. Otherwise, some of the material printed in the
boxes may not be output, or may be formatted incorrectly.
In case of interactive use, the system closes all opened boxes and
flushes all pending text (as with the [print_newline] function)
after each phrase. Each phrase is therefore executed in the initial
state of the pretty-printer.
Warning: the material output by the following functions is delayed
in the pretty-printer queue in order to compute the proper line
breaking. Hence, you should not mix calls to the printing functions
of the basic I/O system with calls to the functions of this module:
this could result in some strange output seemingly unrelated with
the evaluation order of printing commands.
*)
(** {6 Boxes} *)
val open_box : int -> unit;;
(** [open_box d] opens a new pretty-printing box
with offset [d].
This box is the general purpose pretty-printing box.
Material in this box is displayed 'horizontal or vertical':
break hints inside the box may lead to a new line, if there
is no more room on the line to print the remainder of the box,
or if a new line may lead to a new indentation
(demonstrating the indentation of the box).
When a new line is printed in the box, [d] is added to the
current indentation. *)
val close_box : unit -> unit;;
(** Closes the most recently opened pretty-printing box. *)
(** {6 Formatting functions} *)
val print_string : string -> unit;;
(** [print_string str] prints [str] in the current box. *)
val print_as : int -> string -> unit;;
(** [print_as len str] prints [str] in the
current box. The pretty-printer formats [str] as if
it were of length [len]. *)
val print_int : int -> unit;;
(** Prints an integer in the current box. *)
val print_float : float -> unit;;
(** Prints a floating point number in the current box. *)
val print_char : char -> unit;;
(** Prints a character in the current box. *)
val print_bool : bool -> unit;;
(** Prints a boolean in the current box. *)
(** {6 Break hints} *)
val print_space : unit -> unit;;
(** [print_space ()] is used to separate items (typically to print
a space between two words).
It indicates that the line may be split at this
point. It either prints one space or splits the line.
It is equivalent to [print_break 1 0]. *)
val print_cut : unit -> unit;;
(** [print_cut ()] is used to mark a good break position.
It indicates that the line may be split at this
point. It either prints nothing or splits the line.
This allows line splitting at the current
point, without printing spaces or adding indentation.
It is equivalent to [print_break 0 0]. *)
val print_break : int -> int -> unit;;
(** Inserts a break hint in a pretty-printing box.
[print_break nspaces offset] indicates that the line may
be split (a newline character is printed) at this point,
if the contents of the current box does not fit on the
current line.
If the line is split at that point, [offset] is added to
the current indentation. If the line is not split,
[nspaces] spaces are printed. *)
val print_flush : unit -> unit;;
(** Flushes the pretty printer: all opened boxes are closed,
and all pending text is displayed. *)
val print_newline : unit -> unit;;
(** Equivalent to [print_flush] followed by a new line. *)
val force_newline : unit -> unit;;
(** Forces a newline in the current box. Not the normal way of
pretty-printing, you should prefer break hints. *)
val print_if_newline : unit -> unit;;
(** Executes the next formatting command if the preceding line
has just been split. Otherwise, ignore the next formatting
command. *)
(** {6 Margin} *)
val set_margin : int -> unit;;
(** [set_margin d] sets the value of the right margin
to [d] (in characters): this value is used to detect line
overflows that leads to split lines.
Nothing happens if [d] is smaller than 2.
If [d] is too large, the right margin is set to the maximum
admissible value (which is greater than [10^9]). *)
val get_margin : unit -> int;;
(** Returns the position of the right margin. *)
(** {6 Maximum indentation limit} *)
val set_max_indent : int -> unit;;
(** [set_max_indent d] sets the value of the maximum
indentation limit to [d] (in characters):
once this limit is reached, boxes are rejected to the left,
if they do not fit on the current line.
Nothing happens if [d] is smaller than 2.
If [d] is too large, the limit is set to the maximum
admissible value (which is greater than [10^9]). *)
val get_max_indent : unit -> int;;
(** Return the value of the maximum indentation limit (in characters). *)
(** {6 Formatting depth: maximum number of boxes allowed before ellipsis} *)
val set_max_boxes : int -> unit;;
(** [set_max_boxes max] sets the maximum number of boxes simultaneously
opened.
Material inside boxes nested deeper is printed as an ellipsis (more
precisely as the text returned by [get_ellipsis_text ()]).
Nothing happens if [max] is smaller than 2. *)
val get_max_boxes : unit -> int;;
(** Returns the maximum number of boxes allowed before ellipsis. *)
val over_max_boxes : unit -> bool;;
(** Tests if the maximum number of boxes allowed have already been opened. *)
(** {6 Advanced formatting} *)
val open_hbox : unit -> unit;;
(** [open_hbox ()] opens a new pretty-printing box.
This box is 'horizontal': the line is not split in this box
(new lines may still occur inside boxes nested deeper). *)
val open_vbox : int -> unit;;
(** [open_vbox d] opens a new pretty-printing box
with offset [d].
This box is 'vertical': every break hint inside this
box leads to a new line.
When a new line is printed in the box, [d] is added to the
current indentation. *)
val open_hvbox : int -> unit;;
(** [open_hvbox d] opens a new pretty-printing box
with offset [d].
This box is 'horizontal-vertical': it behaves as an
'horizontal' box if it fits on a single line,
otherwise it behaves as a 'vertical' box.
When a new line is printed in the box, [d] is added to the
current indentation. *)
val open_hovbox : int -> unit;;
(** [open_hovbox d] opens a new pretty-printing box
with offset [d].
This box is 'horizontal or vertical': break hints
inside this box may lead to a new line, if there is no more room
on the line to print the remainder of the box.
When a new line is printed in the box, [d] is added to the
current indentation. *)
(** {6 Tabulations} *)
val open_tbox : unit -> unit;;
(** Opens a tabulation box. *)
val close_tbox : unit -> unit;;
(** Closes the most recently opened tabulation box. *)
val print_tbreak : int -> int -> unit;;
(** Break hint in a tabulation box.
[print_tbreak spaces offset] moves the insertion point to
the next tabulation ([spaces] being added to this position).
Nothing occurs if insertion point is already on a
tabulation mark.
If there is no next tabulation on the line, then a newline
is printed and the insertion point moves to the first
tabulation of the box.
If a new line is printed, [offset] is added to the current
indentation. *)
val set_tab : unit -> unit;;
(** Sets a tabulation mark at the current insertion point. *)
val print_tab : unit -> unit;;
(** [print_tab ()] is equivalent to [print_tbreak 0 0]. *)
(** {6 Ellipsis} *)
val set_ellipsis_text : string -> unit;;
(** Set the text of the ellipsis printed when too many boxes
are opened (a single dot, [.], by default). *)
val get_ellipsis_text : unit -> string;;
(** Return the text of the ellipsis. *)
(** {6:tags Semantics Tags} *)
type tag = string;;
(** {i Semantics tags} (or simply {e tags}) are used to decorate printed
entities for user's defined purposes, e.g. setting font and giving size
indications for a display device, or marking delimitation of semantics
entities (e.g. HTML or TeX elements or terminal escape sequences).
By default, those tags do not influence line breaking calculation:
the tag 'markers' are not considered as part of the printing
material that drives line breaking (in other words, the length of
those strings is considered as zero for line breaking).
Thus, tag handling is in some sense transparent to pretty-printing
and does not interfere with usual indentation. Hence, a single
pretty printing routine can output both simple 'verbatim'
material or richer decorated output depending on the treatment of
tags. By default, tags are not active, hence the output is not
decorated with tag information. Once [set_tags] is set to [true],
the pretty printer engine honours tags and decorates the output
accordingly.
When a tag has been opened (or closed), it is both and successively
'printed' and 'marked'. Printing a tag means calling a
formatter specific function with the name of the tag as argument:
that 'tag printing' function can then print any regular material
to the formatter (so that this material is enqueued as usual in the
formatter queue for further line-breaking computation). Marking a
tag means to output an arbitrary string (the 'tag marker'),
directly into the output device of the formatter. Hence, the
formatter specific 'tag marking' function must return the tag
marker string associated to its tag argument. Being flushed
directly into the output device of the formatter, tag marker
strings are not considered as part of the printing material that
drives line breaking (in other words, the length of the strings
corresponding to tag markers is considered as zero for line
breaking). In addition, advanced users may take advantage of
the specificity of tag markers to be precisely output when the
pretty printer has already decided where to break the lines, and
precisely when the queue is flushed into the output device.
In the spirit of HTML tags, the default tag marking functions
output tags enclosed in "<" and ">": hence, the opening marker of
tag [t] is ["<t>"] and the closing marker ["</t>"].
Default tag printing functions just do nothing.
Tag marking and tag printing functions are user definable and can
be set by calling [set_formatter_tag_functions]. *)
val open_tag : tag -> unit;;
(** [open_tag t] opens the tag named [t]; the [print_open_tag]
function of the formatter is called with [t] as argument;
the tag marker [mark_open_tag t] will be flushed into the output
device of the formatter. *)
val close_tag : unit -> unit;;
(** [close_tag ()] closes the most recently opened tag [t].
In addition, the [print_close_tag] function of the formatter is called
with [t] as argument. The marker [mark_close_tag t] will be flushed
into the output device of the formatter. *)
val set_tags : bool -> unit;;
(** [set_tags b] turns on or off the treatment of tags (default is off). *)
val set_print_tags : bool -> unit;;
val set_mark_tags : bool -> unit;;
(** [set_print_tags b] turns on or off the printing of tags, while
[set_mark_tags b] turns on or off the output of tag markers. *)
val get_print_tags : unit -> bool;;
val get_mark_tags : unit -> bool;;
(** Return the current status of tags printing and tags marking. *)
(** {6 Redirecting the standard formatter output} *)
val set_formatter_out_channel : Pervasives.out_channel -> unit;;
(** Redirect the pretty-printer output to the given channel.
(All the output functions of the standard formatter are set to the
default output functions printing to the given channel.) *)
val set_formatter_output_functions :
(string -> int -> int -> unit) -> (unit -> unit) -> unit
;;
(** [set_formatter_output_functions out flush] redirects the
pretty-printer output functions to the functions [out] and
[flush].
The [out] function performs all the pretty-printer string output.
It is called with a string [s], a start position [p], and a number of
characters [n]; it is supposed to output characters [p] to [p + n - 1] of
[s].
The [flush] function is called whenever the pretty-printer is flushed
(via conversion [%!], or pretty-printing indications [@?] or [@.], or
using low level functions [print_flush] or [print_newline]). *)
val get_formatter_output_functions :
unit -> (string -> int -> int -> unit) * (unit -> unit)
;;
(** Return the current output functions of the pretty-printer. *)
(** {6:meaning Changing the meaning of standard formatter pretty printing} *)
(** The [Format] module is versatile enough to let you completely redefine
the meaning of pretty printing: you may provide your own functions to define
how to handle indentation, line breaking, and even printing of all the
characters that have to be printed! *)
type formatter_out_functions = {
out_string : string -> int -> int -> unit;
out_flush : unit -> unit;
out_newline : unit -> unit;
out_spaces : int -> unit;
}
;;
val set_formatter_out_functions : formatter_out_functions -> unit;;
(** [set_formatter_out_functions out_funs]
Redirect the pretty-printer output to the functions [out_funs.out_string]
and [out_funs.out_flush] as described in
[set_formatter_output_functions]. In addition, the pretty-printer function
that outputs a newline is set to the function [out_funs.out_newline] and
the function that outputs indentation spaces is set to the function
[out_funs.out_spaces].
This way, you can change the meaning of indentation (which can be
something else than just printing space characters) and the meaning of new
lines opening (which can be connected to any other action needed by the
application at hand). The two functions [out_spaces] and [out_newline] are
normally connected to [out_string] and [out_flush]: respective default
values for [out_space] and [out_newline] are
[out_string (String.make n ' ') 0 n] and [out_string "\n" 0 1]. *)
val get_formatter_out_functions : unit -> formatter_out_functions;;
(** Return the current output functions of the pretty-printer,
including line breaking and indentation functions. Useful to record the
current setting and restore it afterwards. *)
(** {6:tagsmeaning Changing the meaning of printing semantics tags} *)
type formatter_tag_functions = {
mark_open_tag : tag -> string;
mark_close_tag : tag -> string;
print_open_tag : tag -> unit;
print_close_tag : tag -> unit;
}
;;
(** The tag handling functions specific to a formatter:
[mark] versions are the 'tag marking' functions that associate a string
marker to a tag in order for the pretty-printing engine to flush
those markers as 0 length tokens in the output device of the formatter.
[print] versions are the 'tag printing' functions that can perform
regular printing when a tag is closed or opened. *)
val set_formatter_tag_functions : formatter_tag_functions -> unit;;
(** [set_formatter_tag_functions tag_funs] changes the meaning of
opening and closing tags to use the functions in [tag_funs].
When opening a tag name [t], the string [t] is passed to the
opening tag marking function (the [mark_open_tag] field of the
record [tag_funs]), that must return the opening tag marker for
that name. When the next call to [close_tag ()] happens, the tag
name [t] is sent back to the closing tag marking function (the
[mark_close_tag] field of record [tag_funs]), that must return a
closing tag marker for that name.
The [print_] field of the record contains the functions that are
called at tag opening and tag closing time, to output regular
material in the pretty-printer queue. *)
val get_formatter_tag_functions : unit -> formatter_tag_functions;;
(** Return the current tag functions of the pretty-printer. *)
(** {6 Multiple formatted output} *)
type formatter;;
(** Abstract data corresponding to a pretty-printer (also called a
formatter) and all its machinery.
Defining new pretty-printers permits unrelated output of material in
parallel on several output channels.
All the parameters of a pretty-printer are local to this pretty-printer:
margin, maximum indentation limit, maximum number of boxes
simultaneously opened, ellipsis, and so on, are specific to
each pretty-printer and may be fixed independently.
Given a [Pervasives.out_channel] output channel [oc], a new formatter
writing to that channel is simply obtained by calling
[formatter_of_out_channel oc].
Alternatively, the [make_formatter] function allocates a new
formatter with explicit output and flushing functions
(convenient to output material to strings for instance).
*)
val formatter_of_out_channel : out_channel -> formatter;;
(** [formatter_of_out_channel oc] returns a new formatter that
writes to the corresponding channel [oc]. *)
val std_formatter : formatter;;
(** The standard formatter used by the formatting functions
above. It is defined as [formatter_of_out_channel stdout]. *)
val err_formatter : formatter;;
(** A formatter to use with formatting functions below for
output to standard error. It is defined as
[formatter_of_out_channel stderr]. *)
val formatter_of_buffer : Buffer.t -> formatter;;
(** [formatter_of_buffer b] returns a new formatter writing to
buffer [b]. As usual, the formatter has to be flushed at
the end of pretty printing, using [pp_print_flush] or
[pp_print_newline], to display all the pending material. *)
val stdbuf : Buffer.t;;
(** The string buffer in which [str_formatter] writes. *)
val str_formatter : formatter;;
(** A formatter to use with formatting functions below for
output to the [stdbuf] string buffer.
[str_formatter] is defined as [formatter_of_buffer stdbuf]. *)
val flush_str_formatter : unit -> string;;
(** Returns the material printed with [str_formatter], flushes
the formatter and resets the corresponding buffer. *)
val make_formatter :
(string -> int -> int -> unit) -> (unit -> unit) -> formatter
;;
(** [make_formatter out flush] returns a new formatter that writes according
to the output function [out], and the flushing function [flush]. For
instance, a formatter to the [Pervasives.out_channel] [oc] is returned by
[make_formatter (Pervasives.output oc) (fun () -> Pervasives.flush oc)]. *)
(** {6 Basic functions to use with formatters} *)
val pp_open_hbox : formatter -> unit -> unit;;
val pp_open_vbox : formatter -> int -> unit;;
val pp_open_hvbox : formatter -> int -> unit;;
val pp_open_hovbox : formatter -> int -> unit;;
val pp_open_box : formatter -> int -> unit;;
val pp_close_box : formatter -> unit -> unit;;
val pp_open_tag : formatter -> string -> unit;;
val pp_close_tag : formatter -> unit -> unit;;
val pp_print_string : formatter -> string -> unit;;
val pp_print_as : formatter -> int -> string -> unit;;
val pp_print_int : formatter -> int -> unit;;
val pp_print_float : formatter -> float -> unit;;
val pp_print_char : formatter -> char -> unit;;
val pp_print_bool : formatter -> bool -> unit;;
val pp_print_break : formatter -> int -> int -> unit;;
val pp_print_cut : formatter -> unit -> unit;;
val pp_print_space : formatter -> unit -> unit;;
val pp_force_newline : formatter -> unit -> unit;;
val pp_print_flush : formatter -> unit -> unit;;
val pp_print_newline : formatter -> unit -> unit;;
val pp_print_if_newline : formatter -> unit -> unit;;
val pp_open_tbox : formatter -> unit -> unit;;
val pp_close_tbox : formatter -> unit -> unit;;
val pp_print_tbreak : formatter -> int -> int -> unit;;
val pp_set_tab : formatter -> unit -> unit;;
val pp_print_tab : formatter -> unit -> unit;;
val pp_set_tags : formatter -> bool -> unit;;
val pp_set_print_tags : formatter -> bool -> unit;;
val pp_set_mark_tags : formatter -> bool -> unit;;
val pp_get_print_tags : formatter -> unit -> bool;;
val pp_get_mark_tags : formatter -> unit -> bool;;
val pp_set_margin : formatter -> int -> unit;;
val pp_get_margin : formatter -> unit -> int;;
val pp_set_max_indent : formatter -> int -> unit;;
val pp_get_max_indent : formatter -> unit -> int;;
val pp_set_max_boxes : formatter -> int -> unit;;
val pp_get_max_boxes : formatter -> unit -> int;;
val pp_over_max_boxes : formatter -> unit -> bool;;
val pp_set_ellipsis_text : formatter -> string -> unit;;
val pp_get_ellipsis_text : formatter -> unit -> string;;
val pp_set_formatter_out_channel :
formatter -> Pervasives.out_channel -> unit
;;
val pp_set_formatter_output_functions :
formatter -> (string -> int -> int -> unit) -> (unit -> unit) -> unit
;;
val pp_get_formatter_output_functions :
formatter -> unit -> (string -> int -> int -> unit) * (unit -> unit)
;;
val pp_set_formatter_tag_functions :
formatter -> formatter_tag_functions -> unit
;;
val pp_get_formatter_tag_functions :
formatter -> unit -> formatter_tag_functions
;;
val pp_set_formatter_out_functions :
formatter -> formatter_out_functions -> unit
;;
val pp_get_formatter_out_functions :
formatter -> unit -> formatter_out_functions
;;
(** These functions are the basic ones: usual functions
operating on the standard formatter are defined via partial
evaluation of these primitives. For instance,
[print_string] is equal to [pp_print_string std_formatter]. *)
(** {6 [printf] like functions for pretty-printing.} *)
val fprintf : formatter -> ('a, formatter, unit) format -> 'a;;
(** [fprintf ff fmt arg1 ... argN] formats the arguments [arg1] to [argN]
according to the format string [fmt], and outputs the resulting string on
the formatter [ff].
The format [fmt] is a character string which contains three types of
objects: plain characters and conversion specifications as specified in
the [Printf] module, and pretty-printing indications specific to the
[Format] module.
The pretty-printing indication characters are introduced by
a [@] character, and their meanings are:
- [@\[]: open a pretty-printing box. The type and offset of the
box may be optionally specified with the following syntax:
the [<] character, followed by an optional box type indication,
then an optional integer offset, and the closing [>] character.
Box type is one of [h], [v], [hv], [b], or [hov],
which stand respectively for an horizontal box, a vertical box,
an 'horizontal-vertical' box, or an 'horizontal or
vertical' box ([b] standing for an 'horizontal or
vertical' box demonstrating indentation and [hov] standing
for a regular'horizontal or vertical' box).
For instance, [@\[<hov 2>] opens an 'horizontal or vertical'
box with indentation 2 as obtained with [open_hovbox 2].
For more details about boxes, see the various box opening
functions [open_*box].
- [@\]]: close the most recently opened pretty-printing box.
- [@,]: output a good break hint, as with [print_cut ()].
- [@ ]: output a good break space, as with [print_space ()].
- [@;]: output a fully specified good break as with [print_break]. The
[nspaces] and [offset] parameters of the break may be
optionally specified with the following syntax:
the [<] character, followed by an integer [nspaces] value,
then an integer [offset], and a closing [>] character.
If no parameters are provided, the good break defaults to a
good break space.
- [@.]: flush the pretty printer and output a new line, as with
[print_newline ()].
- [@<n>]: print the following item as if it were of length [n].
Hence, [printf "@<0>%s" arg] prints [arg] as a zero length string.
If [@<n>] is not followed by a conversion specification,
then the following character of the format is printed as if
it were of length [n].
- [@\{]: open a tag. The name of the tag may be optionally
specified with the following syntax:
the [<] character, followed by an optional string
specification, and the closing [>] character. The string
specification is any character string that does not contain the
closing character ['>']. If omitted, the tag name defaults to the
empty string.
For more details about tags, see the functions [open_tag] and
[close_tag].
- [@\}]: close the most recently opened tag.
- [@?]: flush the pretty printer as with [print_flush ()].
This is equivalent to the conversion [%!].
- [@\n]: force a newline, as with [force_newline ()].
- [@@]: print a single [@] character.
Example: [printf "@[%s@ %d@]@." "x =" 1] is equivalent to
[open_box (); print_string "x ="; print_space ();
print_int 1; close_box (); print_newline ()].
It prints [x = 1] within a pretty-printing box.
Note: If you need to prevent the interpretation of a [@] character as a
pretty-printing indication, escape it with a [%] character, as usual in
format strings.
@since 3.12.2
*)
val printf : ('a, formatter, unit) format -> 'a;;
(** Same as [fprintf] above, but output on [std_formatter]. *)
val eprintf : ('a, formatter, unit) format -> 'a;;
(** Same as [fprintf] above, but output on [err_formatter]. *)
val sprintf : ('a, unit, string) format -> 'a;;
(** Same as [printf] above, but instead of printing on a formatter,
returns a string containing the result of formatting the arguments.
Note that the pretty-printer queue is flushed at the end of {e each
call} to [sprintf].
In case of multiple and related calls to [sprintf] to output
material on a single string, you should consider using [fprintf]
with the predefined formatter [str_formatter] and call
[flush_str_formatter ()] to get the final result.
Alternatively, you can use [Format.fprintf] with a formatter writing to a
buffer of your own: flushing the formatter and the buffer at the end of
pretty-printing returns the desired string.
*)
val asprintf : ('a, formatter, unit, string) format4 -> 'a;;
(** Same as [printf] above, but instead of printing on a formatter,
returns a string containing the result of formatting the arguments.
The type of [asprintf] is general enough to interact nicely with [%a]
conversions.
@since 4.01.0
*)
val ifprintf : formatter -> ('a, formatter, unit) format -> 'a;;
(** Same as [fprintf] above, but does not print anything.
Useful to ignore some material when conditionally printing.
@since 3.10.0
*)
(** Formatted output functions with continuations. *)
val kfprintf : (formatter -> 'a) -> formatter ->
('b, formatter, unit, 'a) format4 -> 'b
;;
(** Same as [fprintf] above, but instead of returning immediately,
passes the formatter to its first argument at the end of printing. *)
val ikfprintf : (formatter -> 'a) -> formatter ->
('b, formatter, unit, 'a) format4 -> 'b
;;
(** Same as [kfprintf] above, but does not print anything.
Useful to ignore some material when conditionally printing.
@since 3.12.0
*)
val ksprintf : (string -> 'a) -> ('b, unit, string, 'a) format4 -> 'b;;
(** Same as [sprintf] above, but instead of returning the string,
passes it to the first argument. *)
(** {6 Deprecated} *)
val bprintf : Buffer.t -> ('a, formatter, unit) format -> 'a;;
(** A deprecated and error prone function. Do not use it.
If you need to print to some buffer [b], you must first define a
formatter writing to [b], using [let to_b = formatter_of_buffer b]; then
use regular calls to [Format.fprintf] on formatter [to_b]. *)
val kprintf : (string -> 'a) -> ('b, unit, string, 'a) format4 -> 'b;;
(** A deprecated synonym for [ksprintf]. *)
val set_all_formatter_output_functions :
out:(string -> int -> int -> unit) ->
flush:(unit -> unit) ->
newline:(unit -> unit) ->
spaces:(int -> unit) ->
unit
;;
(** Deprecated. Subsumed by [set_formatter_out_functions].
@since 4.00.0
*)
val get_all_formatter_output_functions :
unit ->
(string -> int -> int -> unit) *
(unit -> unit) *
(unit -> unit) *
(int -> unit)
;;
(** Deprecated. Subsumed by [get_formatter_out_functions].
@since 4.00.0
*)
val pp_set_all_formatter_output_functions :
formatter -> out:(string -> int -> int -> unit) -> flush:(unit -> unit) ->
newline:(unit -> unit) -> spaces:(int -> unit) -> unit
;;
(** Deprecated. Subsumed by [pp_set_formatter_out_functions].
@since 4.01.0
*)
val pp_get_all_formatter_output_functions :
formatter -> unit ->
(string -> int -> int -> unit) * (unit -> unit) * (unit -> unit) *
(int -> unit)
;;
(** Deprecated. Subsumed by [pp_get_formatter_out_functions].
@since 4.01.0
*)
|