1Format(3) OCaml library Format(3)
2
6 Format - Pretty-printing.
7
9 Module Format
10
12 Module Format
13 : sig end
14 Pretty-printing.
17 This module implements a pretty-printing facility to format values
19 within Format.boxes and Format.tags combined with a set of Format.fpp .
20 The pretty-printer splits lines at specified Format.breaks , and in‐
21 dents lines according to the box structure. Similarly, Format.tags can
22 be used to decouple text presentation from its contents.
23 This pretty-printing facility is implemented as an overlay on top of
25 abstract Format.formatter which provide basic output functions. Some
26 formatters are predefined, notably:
27 - Format.std_formatter outputs to stdout
29 - Format.err_formatter outputs to stderr
32 Most functions in the Format module come in two variants: a short ver‐
34 sion that operates on Format.std_formatter and the generic version pre‐
35 fixed by pp_ that takes a formatter as its first argument.
36 More formatters can be created with Format.formatter_of_out_channel ,
38 Format.formatter_of_buffer , Format.formatter_of_symbolic_output_buffer
39 or using Format.formatter .
40 Introduction
48 You may consider this module as providing an extension to the printf
49 facility to provide automatic line splitting. The addition of
50 pretty-printing annotations to your regular printf format strings gives
51 you fancy indentation and line breaks. Pretty-printing annotations are
52 described below in the documentation of the function Format.fprintf .
53 You may also use the explicit pretty-printing box management and print‐
55 ing functions provided by this module. This style is more basic but
56 more verbose than the concise fprintf format strings.
57 For instance, the sequence open_box 0; print_string "x ="; print_space
59 ();
60 print_int 1; close_box (); print_newline () that prints x = 1
61 within a pretty-printing box, can be abbreviated as printf "@[%s@
62 %i@]@." "x =" 1 , or even shorter printf "@[x =@ %i@]@." 1 .
63 Rule of thumb for casual users of this library:
65 -use simple pretty-printing boxes (as obtained by open_box 0 );
67 -use simple break hints as obtained by print_cut () that outputs a sim‐
69 ple break hint, or by print_space () that outputs a space indicating a
70 break hint;
71 -once a pretty-printing box is open, display its material with basic
73 printing functions (e. g. print_int and print_string );
74 -when the material for a pretty-printing box has been printed, call
76 close_box () to close the box;
77 -at the end of pretty-printing, flush the pretty-printer to display all
79 the remaining material, e.g. evaluate print_newline () .
80 The behavior of pretty-printing commands is unspecified if there is no
82 open pretty-printing box. Each box opened by one of the open_ functions
83 below must be closed using close_box for proper formatting. Otherwise,
84 some of the material printed in the boxes may not be output, or may be
85 formatted incorrectly.
86 In case of interactive use, each phrase is executed in the initial
88 state of the standard pretty-printer: after each phrase execution, the
89 interactive system closes all open pretty-printing boxes, flushes all
90 pending text, and resets the standard pretty-printer.
91 Warning: mixing calls to pretty-printing functions of this module with
93 calls to Stdlib low level output functions is error prone.
94 The pretty-printing functions output material that is delayed in the
96 pretty-printer queue and stacks in order to compute proper line split‐
97 ting. In contrast, basic I/O output functions write directly in their
98 output device. As a consequence, the output of a basic I/O function may
99 appear before the output of a pretty-printing function that has been
100 called before. For instance,
101 Stdlib.print_string "<";
102 Format.print_string "PRETTY";
103 Stdlib.print_string ">";
104 Format.print_string "TEXT";
105 leads to output <>PRETTYTEXT .
106 Formatters
108 type formatter
109 Abstract data corresponding to a pretty-printer (also called a format‐
112 ter) and all its machinery. See also Format.formatter .
113 Pretty-printing boxes
118 The pretty-printing engine uses the concepts of pretty-printing box and
119 break hint to drive indentation and line splitting behavior of the
120 pretty-printer.
121 Each different pretty-printing box kind introduces a specific line
123 splitting policy:
124 -within an horizontal box, break hints never split the line (but the
127 line may be split in a box nested deeper),
128 -within a vertical box, break hints always split the line,
130 -within an horizontal/vertical box, if the box fits on the current line
132 then break hints never split the line, otherwise break hint always
133 split the line,
134 -within a compacting box, a break hint never splits the line, unless
136 there is no more room on the current line.
137 Note that line splitting policy is box specific: the policy of a box
139 does not rule the policy of inner boxes. For instance, if a vertical
140 box is nested in an horizontal box, all break hints within the vertical
141 box will split the line.
142 Moreover, opening a box after the Format.maxindent splits the line
144 whether or not the box would end up fitting on the line.
145 val pp_open_box : formatter -> int -> unit
147 val open_box : int -> unit
152 pp_open_box ppf d opens a new compacting pretty-printing box with off‐
155 set d in the formatter ppf .
156 Within this box, the pretty-printer prints as much as possible material
158 on every line.
159 A break hint splits the line if there is no more room on the line to
161 print the remainder of the box.
162 Within this box, the pretty-printer emphasizes the box structure: if a
164 structural box does not fit fully on a simple line, a break hint also
165 splits the line if the splitting ``moves to the left'' (i.e. the new
166 line gets an indentation smaller than the one of the current line).
167 This box is the general purpose pretty-printing box.
169 If the pretty-printer splits the line in the box, offset d is added to
171 the current indentation.
172 val pp_close_box : formatter -> unit -> unit
176 val close_box : unit -> unit
181 Closes the most recently open pretty-printing box.
183 val pp_open_hbox : formatter -> unit -> unit
187 val open_hbox : unit -> unit
192 pp_open_hbox ppf () opens a new 'horizontal' pretty-printing box.
195 This box prints material on a single line.
197 Break hints in a horizontal box never split the line. (Line splitting
199 may still occur inside boxes nested deeper).
200 val pp_open_vbox : formatter -> int -> unit
204 val open_vbox : int -> unit
209 pp_open_vbox ppf d opens a new 'vertical' pretty-printing box with off‐
212 set d .
213 This box prints material on as many lines as break hints in the box.
215 Every break hint in a vertical box splits the line.
217 If the pretty-printer splits the line in the box, d is added to the
219 current indentation.
220 val pp_open_hvbox : formatter -> int -> unit
224 val open_hvbox : int -> unit
229 pp_open_hvbox ppf d opens a new 'horizontal/vertical' pretty-printing
232 box with offset d .
233 This box behaves as an horizontal box if it fits on a single line, oth‐
235 erwise it behaves as a vertical box.
236 If the pretty-printer splits the line in the box, d is added to the
238 current indentation.
239 val pp_open_hovbox : formatter -> int -> unit
243 val open_hovbox : int -> unit
248 pp_open_hovbox ppf d opens a new 'horizontal-or-vertical' pretty-print‐
251 ing box with offset d .
252 This box prints material as much as possible on every line.
254 A break hint splits the line if there is no more room on the line to
256 print the remainder of the box.
257 If the pretty-printer splits the line in the box, d is added to the
259 current indentation.
260 Formatting functions
265 val pp_print_string : formatter -> string -> unit
266 val print_string : string -> unit
271 pp_print_string ppf s prints s in the current pretty-printing box.
274 val pp_print_bytes : formatter -> bytes -> unit
278 val print_bytes : bytes -> unit
283 pp_print_bytes ppf b prints b in the current pretty-printing box.
286 Since 4.13.0
289 val pp_print_as : formatter -> int -> string -> unit
293 val print_as : int -> string -> unit
298 pp_print_as ppf len s prints s in the current pretty-printing box. The
301 pretty-printer formats s as if it were of length len .
302 val pp_print_int : formatter -> int -> unit
306 val print_int : int -> unit
311 Print an integer in the current pretty-printing box.
313 val pp_print_float : formatter -> float -> unit
317 val print_float : float -> unit
322 Print a floating point number in the current pretty-printing box.
324 val pp_print_char : formatter -> char -> unit
328 val print_char : char -> unit
333 Print a character in the current pretty-printing box.
335 val pp_print_bool : formatter -> bool -> unit
339 val print_bool : bool -> unit
344 Print a boolean in the current pretty-printing box.
346 Break hints
351 A 'break hint' tells the pretty-printer to output some space or split
352 the line whichever way is more appropriate to the current pretty-print‐
353 ing box splitting rules.
354 Break hints are used to separate printing items and are mandatory to
356 let the pretty-printer correctly split lines and indent items.
357 Simple break hints are:
359 -the 'space': output a space or split the line if appropriate,
361 -the 'cut': split the line if appropriate.
363 Note: the notions of space and line splitting are abstract for the
365 pretty-printing engine, since those notions can be completely redefined
366 by the programmer. However, in the pretty-printer default setting,
367 ``output a space'' simply means printing a space character (ASCII code
368 32) and ``split the line'' means printing a newline character (ASCII
369 code 10).
370 val pp_print_space : formatter -> unit -> unit
372 val print_space : unit -> unit
377 pp_print_space ppf () emits a 'space' break hint: the pretty-printer
380 may split the line at this point, otherwise it prints one space.
381 pp_print_space ppf () is equivalent to pp_print_break ppf 1 0 .
384 val pp_print_cut : formatter -> unit -> unit
388 val print_cut : unit -> unit
393 pp_print_cut ppf () emits a 'cut' break hint: the pretty-printer may
396 split the line at this point, otherwise it prints nothing.
397 pp_print_cut ppf () is equivalent to pp_print_break ppf 0 0 .
400 val pp_print_break : formatter -> int -> int -> unit
404 val print_break : int -> int -> unit
409 pp_print_break ppf nspaces offset emits a 'full' break hint: the
412 pretty-printer may split the line at this point, otherwise it prints
413 nspaces spaces.
414 If the pretty-printer splits the line, offset is added to the current
416 indentation.
417 val pp_print_custom_break : formatter -> fits:string * int * string ->
421 breaks:string * int * string -> unit
422 pp_print_custom_break ppf ~fits:(s1, n, s2) ~breaks:(s3, m, s4) emits a
425 custom break hint: the pretty-printer may split the line at this point.
426 If it does not split the line, then the s1 is emitted, then n spaces,
428 then s2 .
429 If it splits the line, then it emits the s3 string, then an indent (ac‐
431 cording to the box rules), then an offset of m spaces, then the s4
432 string.
433 While n and m are handled by formatter_out_functions.out_indent , the
435 strings will be handled by formatter_out_functions.out_string . This
436 allows for a custom formatter that handles indentation distinctly, for
437 example, outputs <br/> tags or entities.
438 The custom break is useful if you want to change which visible
440 (non-whitespace) characters are printed in case of break or no break.
441 For example, when printing a list [a; b; c] , you might want to add a
442 trailing semicolon when it is printed vertically:
443 [
446 a;
447 b;
448 c;
449 ]
450 You can do this as follows:
453 printf "@[<v 0>[@;<0 2>@[<v 0>a;@,b;@,c@]%t]@]@\n"
454 (pp_print_custom_break ~fits:("", 0, "") ~breaks:(";", 0, ""))
455 Since 4.08.0
459 val pp_force_newline : formatter -> unit -> unit
463 val force_newline : unit -> unit
468 Force a new line in the current pretty-printing box.
470 The pretty-printer must split the line at this point,
472 Not the normal way of pretty-printing, since imperative line splitting
474 may interfere with current line counters and box size calculation. Us‐
475 ing break hints within an enclosing vertical box is a better alterna‐
476 tive.
477 val pp_print_if_newline : formatter -> unit -> unit
481 val print_if_newline : unit -> unit
486 Execute the next formatting command if the preceding line has just been
488 split. Otherwise, ignore the next formatting command.
489 Pretty-printing termination
494 val pp_print_flush : formatter -> unit -> unit
495 val print_flush : unit -> unit
500 End of pretty-printing: resets the pretty-printer to initial state.
502 All open pretty-printing boxes are closed, all pending text is printed.
504 In addition, the pretty-printer low level output device is flushed to
505 ensure that all pending text is really displayed.
506 Note: never use print_flush in the normal course of a pretty-printing
508 routine, since the pretty-printer uses a complex buffering machinery to
509 properly indent the output; manually flushing those buffers at random
510 would conflict with the pretty-printer strategy and result to poor ren‐
511 dering.
512 Only consider using print_flush when displaying all pending material is
514 mandatory (for instance in case of interactive use when you want the
515 user to read some text) and when resetting the pretty-printer state
516 will not disturb further pretty-printing.
517 Warning: If the output device of the pretty-printer is an output chan‐
519 nel, repeated calls to print_flush means repeated calls to flush to
520 flush the out channel; these explicit flush calls could foil the
521 buffering strategy of output channels and could dramatically impact ef‐
522 ficiency.
523 val pp_print_newline : formatter -> unit -> unit
527 val print_newline : unit -> unit
532 End of pretty-printing: resets the pretty-printer to initial state.
534 All open pretty-printing boxes are closed, all pending text is printed.
536 Equivalent to Format.print_flush followed by a new line. See corre‐
538 sponding words of caution for Format.print_flush .
539 Note: this is not the normal way to output a new line; the preferred
541 method is using break hints within a vertical pretty-printing box.
542 Margin
547 val pp_set_margin : formatter -> int -> unit
548 val set_margin : int -> unit
553 pp_set_margin ppf d sets the right margin to d (in characters): the
556 pretty-printer splits lines that overflow the right margin according to
557 the break hints given. Setting the margin to d means that the format‐
558 ting engine aims at printing at most d-1 characters per line. Nothing
559 happens if d is smaller than 2. If d is too large, the right margin is
560 set to the maximum admissible value (which is greater than 10 ^ 9 ).
561 If d is less than the current maximum indentation limit, the maximum
562 indentation limit is decreased while trying to preserve a minimal ratio
563 max_indent/margin>=50% and if possible the current difference margin -
564 max_indent .
565 See also Format.pp_set_geometry .
567 val pp_get_margin : formatter -> unit -> int
571 val get_margin : unit -> int
576 Returns the position of the right margin.
578 Maximum indentation limit
583 val pp_set_max_indent : formatter -> int -> unit
584 val set_max_indent : int -> unit
589 pp_set_max_indent ppf d sets the maximum indentation limit of lines to
592 d (in characters): once this limit is reached, new pretty-printing
593 boxes are rejected to the left, unless the enclosing box fully fits on
594 the current line. As an illustration,
595 set_margin 10; set_max_indent 5; printf "@[123456@[7@]89A@]@."
596 yields
597 123456
598 789A
599 because the nested box "@[7@]" is opened after the maximum indentation
601 limit ( 7>5 ) and its parent box does not fit on the current line. Ei‐
602 ther decreasing the length of the parent box to make it fit on a line:
603 printf "@[123456@[7@]89@]@."
604 or opening an intermediary box before the maximum indentation limit
605 which fits on the current line
606 printf "@[123@[456@[7@]89@]A@]@."
607 avoids the rejection to the left of the inner boxes and print respec‐
608 tively "123456789" and "123456789A" . Note also that vertical boxes
609 never fit on a line whereas horizontal boxes always fully fit on the
610 current line. Opening a box may split a line whereas the contents may
611 have fit. If this behavior is problematic, it can be curtailed by set‐
612 ting the maximum indentation limit to margin - 1 . Note that setting
613 the maximum indentation limit to margin is invalid.
614 Nothing happens if d is smaller than 2.
616 If d is too large, the limit is set to the maximum admissible value
618 (which is greater than 10 ^ 9 ).
619 If d is greater or equal than the current margin, it is ignored, and
621 the current maximum indentation limit is kept.
622 See also Format.pp_set_geometry .
624 val pp_get_max_indent : formatter -> unit -> int
628 val get_max_indent : unit -> int
633 Return the maximum indentation limit (in characters).
635 Geometry
640 Geometric functions can be used to manipulate simultaneously the cou‐
641 pled variables, margin and maxixum indentation limit.
642 type geometry = {
644 max_indent : int ;
645 margin : int ;
646 }
647 val check_geometry : geometry -> bool
653 Check if the formatter geometry is valid: 1 < max_indent < margin
655 val pp_set_geometry : formatter -> max_indent:int -> margin:int -> unit
660 val set_geometry : max_indent:int -> margin:int -> unit
665 val pp_safe_set_geometry : formatter -> max_indent:int -> margin:int ->
670 unit
671 val safe_set_geometry : max_indent:int -> margin:int -> unit
676 pp_set_geometry ppf ~max_indent ~margin sets both the margin and maxi‐
679 mum indentation limit for ppf .
680 When 1 < max_indent < margin , pp_set_geometry ppf ~max_indent ~margin
682 is equivalent to pp_set_margin ppf margin; pp_set_max_indent ppf
683 max_indent ; and avoids the subtly incorrect pp_set_max_indent ppf
684 max_indent; pp_set_margin ppf margin ;
685 Outside of this domain, pp_set_geometry raises an invalid argument ex‐
687 ception whereas pp_safe_set_geometry does nothing.
688 Since 4.08.0
691 val pp_update_geometry : formatter -> (geometry -> geometry) -> unit
695 pp_update_geometry ppf (fun geo -> { geo with ... }) lets you update a
698 formatter's geometry in a way that is robust to extension of the geome‐
699 try record with new fields.
700 Raises an invalid argument exception if the returned geometry does not
702 satisfy Format.check_geometry .
703 Since 4.11.0
706 val update_geometry : (geometry -> geometry) -> unit
710 val pp_get_geometry : formatter -> unit -> geometry
715 val get_geometry : unit -> geometry
720 Return the current geometry of the formatter
722 Since 4.08.0
725 Maximum formatting depth
730 The maximum formatting depth is the maximum number of pretty-printing
731 boxes simultaneously open.
732 Material inside boxes nested deeper is printed as an ellipsis (more
734 precisely as the text returned by Format.get_ellipsis_text () ).
735 val pp_set_max_boxes : formatter -> int -> unit
737 val set_max_boxes : int -> unit
742 pp_set_max_boxes ppf max sets the maximum number of pretty-printing
745 boxes simultaneously open.
746 Material inside boxes nested deeper is printed as an ellipsis (more
748 precisely as the text returned by Format.get_ellipsis_text () ).
749 Nothing happens if max is smaller than 2.
751 val pp_get_max_boxes : formatter -> unit -> int
755 val get_max_boxes : unit -> int
760 Returns the maximum number of pretty-printing boxes allowed before el‐
762 lipsis.
763 val pp_over_max_boxes : formatter -> unit -> bool
767 val over_max_boxes : unit -> bool
772 Tests if the maximum number of pretty-printing boxes allowed have al‐
774 ready been opened.
775 Tabulation boxes
780 A tabulation box prints material on lines divided into cells of fixed
781 length. A tabulation box provides a simple way to display vertical col‐
782 umns of left adjusted text.
783 This box features command set_tab to define cell boundaries, and com‐
785 mand print_tab to move from cell to cell and split the line when there
786 is no more cells to print on the line.
787 Note: printing within tabulation box is line directed, so arbitrary
789 line splitting inside a tabulation box leads to poor rendering. Yet,
790 controlled use of tabulation boxes allows simple printing of columns
791 within module Format .
792 val pp_open_tbox : formatter -> unit -> unit
794 val open_tbox : unit -> unit
799 open_tbox () opens a new tabulation box.
802 This box prints lines separated into cells of fixed width.
804 Inside a tabulation box, special tabulation markers defines points of
806 interest on the line (for instance to delimit cell boundaries). Func‐
807 tion Format.set_tab sets a tabulation marker at insertion point.
808 A tabulation box features specific tabulation breaks to move to next
810 tabulation marker or split the line. Function Format.print_tbreak
811 prints a tabulation break.
812 val pp_close_tbox : formatter -> unit -> unit
816 val close_tbox : unit -> unit
821 Closes the most recently opened tabulation box.
823 val pp_set_tab : formatter -> unit -> unit
827 val set_tab : unit -> unit
832 Sets a tabulation marker at current insertion point.
834 val pp_print_tab : formatter -> unit -> unit
838 val print_tab : unit -> unit
843 print_tab () emits a 'next' tabulation break hint: if not already set
846 on a tabulation marker, the insertion point moves to the first tabula‐
847 tion marker on the right, or the pretty-printer splits the line and in‐
848 sertion point moves to the leftmost tabulation marker.
849 It is equivalent to print_tbreak 0 0 .
851 val pp_print_tbreak : formatter -> int -> int -> unit
855 val print_tbreak : int -> int -> unit
860 print_tbreak nspaces offset emits a 'full' tabulation break hint.
863 If not already set on a tabulation marker, the insertion point moves to
865 the first tabulation marker on the right and the pretty-printer prints
866 nspaces spaces.
867 If there is no next tabulation marker on the right, the pretty-printer
869 splits the line at this point, then insertion point moves to the left‐
870 most tabulation marker of the box.
871 If the pretty-printer splits the line, offset is added to the current
873 indentation.
874 Ellipsis
879 val pp_set_ellipsis_text : formatter -> string -> unit
880 val set_ellipsis_text : string -> unit
885 Set the text of the ellipsis printed when too many pretty-printing
887 boxes are open (a single dot, . , by default).
888 val pp_get_ellipsis_text : formatter -> unit -> string
892 val get_ellipsis_text : unit -> string
897 Return the text of the ellipsis.
899 Semantic tags
904 type stag = ..
905 Semantic tags (or simply tags) are user's defined annotations to asso‐
908 ciate user's specific operations to printed entities.
909 Common usage of semantic tags is text decoration to get specific font
911 or text size rendering for a display device, or marking delimitation of
912 entities (e.g. HTML or TeX elements or terminal escape sequences).
913 More sophisticated usage of semantic tags could handle dynamic modifi‐
914 cation of the pretty-printer behavior to properly print the material
915 within some specific tags. For instance, we can define an RGB tag like
916 so:
917 type stag += RGB of {r:int;g:int;b:int}
918 In order to properly delimit printed entities, a semantic tag must be
921 opened before and closed after the entity. Semantic tags must be prop‐
922 erly nested like parentheses using Format.pp_open_stag and For‐
923 mat.pp_close_stag .
924 Tag specific operations occur any time a tag is opened or closed, At
926 each occurrence, two kinds of operations are performed tag-marking and
927 tag-printing:
928 -The tag-marking operation is the simpler tag specific operation: it
930 simply writes a tag specific string into the output device of the for‐
931 matter. Tag-marking does not interfere with line-splitting computation.
932 -The tag-printing operation is the more involved tag specific opera‐
934 tion: it can print arbitrary material to the formatter. Tag-printing is
935 tightly linked to the current pretty-printer operations.
936 Roughly speaking, tag-marking is commonly used to get a better render‐
938 ing of texts in the rendering device, while tag-printing allows fine
939 tuning of printing routines to print the same entity differently ac‐
940 cording to the semantic tags (i.e. print additional material or even
941 omit parts of the output).
942 More precisely: when a semantic tag is opened or closed then both and
944 successive 'tag-printing' and 'tag-marking' operations occur:
945 -Tag-printing a semantic tag means calling the formatter specific func‐
947 tion print_open_stag (resp. print_close_stag ) with the name of the
948 tag as argument: that tag-printing function can then print any regular
949 material to the formatter (so that this material is enqueued as usual
950 in the formatter queue for further line splitting computation).
951 -Tag-marking a semantic tag means calling the formatter specific func‐
953 tion mark_open_stag (resp. mark_close_stag ) with the name of the tag
954 as argument: that tag-marking function can then return the 'tag-opening
955 marker' (resp. `tag-closing marker') for direct output into the output
956 device of the formatter.
957 Being written directly into the output device of the formatter, seman‐
959 tic tag marker strings are not considered as part of the printing mate‐
960 rial that drives line splitting (in other words, the length of the
961 strings corresponding to tag markers is considered as zero for line
962 splitting).
963 Thus, semantic tag handling is in some sense transparent to
965 pretty-printing and does not interfere with usual indentation. Hence, a
966 single pretty-printing routine can output both simple 'verbatim' mate‐
967 rial or richer decorated output depending on the treatment of tags. By
968 default, tags are not active, hence the output is not decorated with
969 tag information. Once set_tags is set to true , the pretty-printer en‐
970 gine honors tags and decorates the output accordingly.
971 Default tag-marking functions behave the HTML way: Format.tag are en‐
973 closed in "<" and ">" while other tags are ignored; hence, opening
974 marker for tag string "t" is "<t>" and closing marker is "</t>" .
975 Default tag-printing functions just do nothing.
977 Tag-marking and tag-printing functions are user definable and can be
979 set by calling Format.set_formatter_stag_functions .
980 Semantic tag operations may be set on or off with Format.set_tags .
982 Tag-marking operations may be set on or off with Format.set_mark_tags .
983 Tag-printing operations may be set on or off with Format.set_print_tags
984 .
985 Since 4.08.0
988 type tag = string
991 type stag +=
996 | String_tag of tag (* String_tag s is a string tag s . String tags
997 can be inserted either by explicitly using the constructor String_tag
998 or by using the dedicated format syntax "@{<s> ... @}" .
999 Since 4.08.0
1002 *)
1003 val pp_open_stag : formatter -> stag -> unit
1009 val open_stag : stag -> unit
1014 pp_open_stag ppf t opens the semantic tag named t .
1017 The print_open_stag tag-printing function of the formatter is called
1019 with t as argument; then the opening tag marker for t , as given by
1020 mark_open_stag t , is written into the output device of the formatter.
1021 Since 4.08.0
1024 val pp_close_stag : formatter -> unit -> unit
1028 val close_stag : unit -> unit
1033 pp_close_stag ppf () closes the most recently opened semantic tag t .
1036 The closing tag marker, as given by mark_close_stag t , is written into
1038 the output device of the formatter; then the print_close_stag
1039 tag-printing function of the formatter is called with t as argument.
1040 Since 4.08.0
1043 val pp_set_tags : formatter -> bool -> unit
1047 val set_tags : bool -> unit
1052 pp_set_tags ppf b turns on or off the treatment of semantic tags (de‐
1055 fault is off).
1056 val pp_set_print_tags : formatter -> bool -> unit
1060 val set_print_tags : bool -> unit
1065 pp_set_print_tags ppf b turns on or off the tag-printing operations.
1068 val pp_set_mark_tags : formatter -> bool -> unit
1072 val set_mark_tags : bool -> unit
1077 pp_set_mark_tags ppf b turns on or off the tag-marking operations.
1080 val pp_get_print_tags : formatter -> unit -> bool
1084 val get_print_tags : unit -> bool
1089 Return the current status of tag-printing operations.
1091 val pp_get_mark_tags : formatter -> unit -> bool
1095 val get_mark_tags : unit -> bool
1100 Return the current status of tag-marking operations.
1102 val pp_set_formatter_out_channel : formatter -> out_channel -> unit
1106 Redirecting the standard formatter output
1109 val set_formatter_out_channel : out_channel -> unit
1110 Redirect the standard pretty-printer output to the given channel. (All
1112 the output functions of the standard formatter are set to the default
1113 output functions printing to the given channel.)
1114 set_formatter_out_channel is equivalent to Format.pp_set_format‐
1117 ter_out_channel std_formatter .
1118 val pp_set_formatter_output_functions : formatter -> (string -> int ->
1122 int -> unit) -> (unit -> unit) -> unit
1123 val set_formatter_output_functions : (string -> int -> int -> unit) ->
1128 (unit -> unit) -> unit
1129 pp_set_formatter_output_functions ppf out flush redirects the standard
1132 pretty-printer output functions to the functions out and flush .
1133 The out function performs all the pretty-printer string output. It is
1135 called with a string s , a start position p , and a number of charac‐
1136 ters n ; it is supposed to output characters p to p + n - 1 of s .
1137 The flush function is called whenever the pretty-printer is flushed
1139 (via conversion %! , or pretty-printing indications @? or @. , or
1140 using low level functions print_flush or print_newline ).
1141 val pp_get_formatter_output_functions : formatter -> unit -> (string ->
1145 int -> int -> unit) * (unit -> unit)
1146 val get_formatter_output_functions : unit -> (string -> int -> int ->
1151 unit) * (unit -> unit)
1152 Return the current output functions of the standard pretty-printer.
1154 Redefining formatter output
1159 The Format module is versatile enough to let you completely redefine
1160 the meaning of pretty-printing output: you may provide your own func‐
1161 tions to define how to handle indentation, line splitting, and even
1162 printing of all the characters that have to be printed!
1163 Redefining output functions
1165 type formatter_out_functions = {
1166 out_string : string -> int -> int -> unit ;
1167 out_flush : unit -> unit ;
1168 out_newline : unit -> unit ;
1169 out_spaces : int -> unit ;
1170 out_indent : int -> unit ; (* .B "Since" 4.06.0
1171 *)
1172 }
1173 The set of output functions specific to a formatter:
1176 -the out_string function performs all the pretty-printer string output.
1178 It is called with a string s , a start position p , and a number of
1179 characters n ; it is supposed to output characters p to p + n - 1 of s
1180 .
1181 -the out_flush function flushes the pretty-printer output device.
1183 - out_newline is called to open a new line when the pretty-printer
1185 splits the line.
1186 -the out_spaces function outputs spaces when a break hint leads to spa‐
1188 ces instead of a line split. It is called with the number of spaces to
1189 output.
1190 -the out_indent function performs new line indentation when the
1192 pretty-printer splits the line. It is called with the indentation value
1193 of the new line.
1194 By default:
1196 -fields out_string and out_flush are output device specific; (e.g.
1198 output_string and flush for a out_channel device, or Buffer.add_sub‐
1199 string and ignore for a Buffer.t output device),
1200 -field out_newline is equivalent to out_string "\n" 0 1 ;
1202 -fields out_spaces and out_indent are equivalent to out_string
1204 (String.make n ' ') 0 n .
1205 Since 4.01.0
1209 val pp_set_formatter_out_functions : formatter -> formatter_out_func‐
1213 tions -> unit
1214 val set_formatter_out_functions : formatter_out_functions -> unit
1219 pp_set_formatter_out_functions ppf out_funs Set all the pretty-printer
1222 output functions of ppf to those of argument out_funs ,
1223 This way, you can change the meaning of indentation (which can be some‐
1225 thing else than just printing space characters) and the meaning of new
1226 lines opening (which can be connected to any other action needed by the
1227 application at hand).
1228 Reasonable defaults for functions out_spaces and out_newline are re‐
1230 spectively out_funs.out_string (String.make n ' ') 0 n and
1231 out_funs.out_string "\n" 0 1 .
1232 Since 4.01.0
1235 val pp_get_formatter_out_functions : formatter -> unit -> format‐
1239 ter_out_functions
1240 val get_formatter_out_functions : unit -> formatter_out_functions
1245 Return the current output functions of the pretty-printer, including
1247 line splitting and indentation functions. Useful to record the current
1248 setting and restore it afterwards.
1249 Since 4.01.0
1252 Redefining semantic tag operations
1257 type formatter_stag_functions = {
1258 mark_open_stag : stag -> string ;
1259 mark_close_stag : stag -> string ;
1260 print_open_stag : stag -> unit ;
1261 print_close_stag : stag -> unit ;
1262 }
1263 The semantic tag handling functions specific to a formatter: mark ver‐
1266 sions are the 'tag-marking' functions that associate a string marker to
1267 a tag in order for the pretty-printing engine to write those markers as
1268 0 length tokens in the output device of the formatter. print versions
1269 are the 'tag-printing' functions that can perform regular printing when
1270 a tag is closed or opened.
1271 Since 4.08.0
1274 val pp_set_formatter_stag_functions : formatter -> formatter_stag_func‐
1278 tions -> unit
1279 val set_formatter_stag_functions : formatter_stag_functions -> unit
1284 pp_set_formatter_stag_functions ppf tag_funs changes the meaning of
1287 opening and closing semantic tag operations to use the functions in
1288 tag_funs when printing on ppf .
1289 When opening a semantic tag with name t , the string t is passed to the
1291 opening tag-marking function (the mark_open_stag field of the record
1292 tag_funs ), that must return the opening tag marker for that name. When
1293 the next call to close_stag () happens, the semantic tag name t is sent
1294 back to the closing tag-marking function (the mark_close_stag field of
1295 record tag_funs ), that must return a closing tag marker for that name.
1296 The print_ field of the record contains the tag-printing functions that
1298 are called at tag opening and tag closing time, to output regular mate‐
1299 rial in the pretty-printer queue.
1300 Since 4.08.0
1303 val pp_get_formatter_stag_functions : formatter -> unit -> format‐
1307 ter_stag_functions
1308 val get_formatter_stag_functions : unit -> formatter_stag_functions
1313 Return the current semantic tag operation functions of the standard
1315 pretty-printer.
1316 Since 4.08.0
1319 Defining formatters
1324 Defining new formatters permits unrelated output of material in paral‐
1325 lel on several output devices. All the parameters of a formatter are
1326 local to the formatter: right margin, maximum indentation limit, maxi‐
1327 mum number of pretty-printing boxes simultaneously open, ellipsis, and
1328 so on, are specific to each formatter and may be fixed independently.
1329 For instance, given a Buffer.t buffer b , Format.formatter_of_buffer b
1331 returns a new formatter using buffer b as its output device. Simi‐
1332 larly, given a out_channel output channel oc , Format.format‐
1333 ter_of_out_channel oc returns a new formatter using channel oc as its
1334 output device.
1335 Alternatively, given out_funs , a complete set of output functions for
1337 a formatter, then Format.formatter_of_out_functions out_funs computes a
1338 new formatter using those functions for output.
1339 val formatter_of_out_channel : out_channel -> formatter
1341 formatter_of_out_channel oc returns a new formatter writing to the cor‐
1344 responding output channel oc .
1345 val std_formatter : formatter
1349 The standard formatter to write to standard output.
1351 It is defined as Format.formatter_of_out_channel stdout .
1353 val err_formatter : formatter
1357 A formatter to write to standard error.
1359 It is defined as Format.formatter_of_out_channel stderr .
1361 val formatter_of_buffer : Buffer.t -> formatter
1365 formatter_of_buffer b returns a new formatter writing to buffer b . At
1368 the end of pretty-printing, the formatter must be flushed using For‐
1369 mat.pp_print_flush or Format.pp_print_newline , to print all the pend‐
1370 ing material into the buffer.
1371 val stdbuf : Buffer.t
1375 The string buffer in which str_formatter writes.
1377 val str_formatter : formatter
1381 A formatter to output to the Format.stdbuf string buffer.
1383 str_formatter is defined as Format.formatter_of_buffer Format.stdbuf .
1386 val flush_str_formatter : unit -> string
1390 Returns the material printed with str_formatter , flushes the formatter
1392 and resets the corresponding buffer.
1393 val make_formatter : (string -> int -> int -> unit) -> (unit -> unit)
1397 -> formatter
1398 make_formatter out flush returns a new formatter that outputs with
1401 function out , and flushes with function flush .
1402 For instance,
1404 make_formatter
1405 (Stdlib.output oc)
1406 (fun () -> Stdlib.flush oc)
1407 returns a formatter to the out_channel oc .
1409 val formatter_of_out_functions : formatter_out_functions -> formatter
1413 formatter_of_out_functions out_funs returns a new formatter that writes
1416 with the set of output functions out_funs .
1417 See definition of type Format.formatter_out_functions for the meaning
1419 of argument out_funs .
1420 Since 4.06.0
1423 Symbolic pretty-printing
1428 Symbolic pretty-printing is pretty-printing using a symbolic formatter,
1429 i.e. a formatter that outputs symbolic pretty-printing items.
1430 When using a symbolic formatter, all regular pretty-printing activities
1432 occur but output material is symbolic and stored in a buffer of output
1433 items. At the end of pretty-printing, flushing the output buffer al‐
1434 lows post-processing of symbolic output before performing low level
1435 output operations.
1436 In practice, first define a symbolic output buffer b using:
1438 - let sob = make_symbolic_output_buffer () . Then define a symbolic
1440 formatter with:
1441 - let ppf = formatter_of_symbolic_output_buffer sob
1443 Use symbolic formatter ppf as usual, and retrieve symbolic items at end
1445 of pretty-printing by flushing symbolic output buffer sob with:
1446 - flush_symbolic_output_buffer sob .
1448 type symbolic_output_item =
1451 | Output_flush (* symbolic flush command
1452 *)
1453 | Output_newline (* symbolic newline command
1454 *)
1455 | Output_string of string
1456 (* Output_string s : symbolic output for string s
1457 *)
1459 | Output_spaces of int
1460 (* Output_spaces n : symbolic command to output n spaces
1461 *)
1462 | Output_indent of int
1463 (* Output_indent i : symbolic indentation of size i
1464 *)
1466 Items produced by symbolic pretty-printers
1469 Since 4.06.0
1472 type symbolic_output_buffer
1475 The output buffer of a symbolic pretty-printer.
1478 Since 4.06.0
1481 val make_symbolic_output_buffer : unit -> symbolic_output_buffer
1485 make_symbolic_output_buffer () returns a fresh buffer for symbolic out‐
1488 put.
1489 Since 4.06.0
1492 val clear_symbolic_output_buffer : symbolic_output_buffer -> unit
1496 clear_symbolic_output_buffer sob resets buffer sob .
1499 Since 4.06.0
1502 val get_symbolic_output_buffer : symbolic_output_buffer -> sym‐
1506 bolic_output_item list
1507 get_symbolic_output_buffer sob returns the contents of buffer sob .
1510 Since 4.06.0
1513 val flush_symbolic_output_buffer : symbolic_output_buffer -> sym‐
1517 bolic_output_item list
1518 flush_symbolic_output_buffer sob returns the contents of buffer sob and
1521 resets buffer sob . flush_symbolic_output_buffer sob is equivalent to
1522 let items = get_symbolic_output_buffer sob in
1523 clear_symbolic_output_buffer sob; items
1524 Since 4.06.0
1528 val add_symbolic_output_item : symbolic_output_buffer -> symbolic_out‐
1532 put_item -> unit
1533 add_symbolic_output_item sob itm adds item itm to buffer sob .
1536 Since 4.06.0
1539 val formatter_of_symbolic_output_buffer : symbolic_output_buffer ->
1543 formatter
1544 formatter_of_symbolic_output_buffer sob returns a symbolic formatter
1547 that outputs to symbolic_output_buffer sob .
1548 Since 4.06.0
1551 Convenience formatting functions.
1556 val pp_print_list : ?pp_sep:(formatter -> unit -> unit) -> (formatter
1557 -> 'a -> unit) -> formatter -> 'a list -> unit
1558 pp_print_list ?pp_sep pp_v ppf l prints items of list l , using pp_v to
1561 print each item, and calling pp_sep between items ( pp_sep defaults to
1562 Format.pp_print_cut . Does nothing on empty lists.
1563 Since 4.02.0
1566 val pp_print_seq : ?pp_sep:(formatter -> unit -> unit) -> (formatter ->
1570 'a -> unit) -> formatter -> 'a Seq.t -> unit
1571 pp_print_seq ?pp_sep pp_v ppf s prints items of sequence s , using pp_v
1574 to print each item, and calling pp_sep between items ( pp_sep defaults
1575 to Format.pp_print_cut . Does nothing on empty sequences.
1576 This function does not terminate on infinite sequences.
1578 Since 4.12
1581 val pp_print_text : formatter -> string -> unit
1585 pp_print_text ppf s prints s with spaces and newlines respectively
1588 printed using Format.pp_print_space and Format.pp_force_newline .
1589 Since 4.02.0
1592 val pp_print_option : ?none:(formatter -> unit -> unit) -> (formatter
1596 -> 'a -> unit) -> formatter -> 'a option -> unit
1597 pp_print_option ?none pp_v ppf o prints o on ppf using pp_v if o is
1600 Some v and none if it is None . none prints nothing by default.
1601 Since 4.08
1604 val pp_print_result : ok:(formatter -> 'a -> unit) -> error:(formatter
1608 -> 'e -> unit) -> formatter -> ('a, 'e) result -> unit
1609 pp_print_result ~ok ~error ppf r prints r on ppf using ok if r is Ok _
1612 and error if r is Error _ .
1613 Since 4.08
1616 val pp_print_either : left:(formatter -> 'a -> unit) -> right:(format‐
1620 ter -> 'b -> unit) -> formatter -> ('a, 'b) Either.t -> unit
1621 pp_print_either ~left ~right ppf e prints e on ppf using left if e is
1624 Either.Left _ and right if e is Either.Right _ .
1625 Since 4.13
1628 Formatted pretty-printing
1633 Module Format provides a complete set of printf like functions for
1634 pretty-printing using format string specifications.
1635 Specific annotations may be added in the format strings to give
1637 pretty-printing commands to the pretty-printing engine.
1638 Those annotations are introduced in the format strings using the @
1640 character. For instance, @ means a space break, @, means a cut, @[
1641 opens a new box, and @] closes the last open box.
1642 val fprintf : formatter -> ('a, formatter, unit) format -> 'a
1644 fprintf ff fmt arg1 ... argN formats the arguments arg1 to argN accord‐
1650 ing to the format string fmt , and outputs the resulting string on the
1651 formatter ff .
1652 The format string fmt is a character string which contains three types
1654 of objects: plain characters and conversion specifications as specified
1655 in the Printf module, and pretty-printing indications specific to the
1656 Format module.
1657 The pretty-printing indication characters are introduced by a @ charac‐
1659 ter, and their meanings are:
1660 - @[ : open a pretty-printing box. The type and offset of the box may
1662 be optionally specified with the following syntax: the < character,
1663 followed by an optional box type indication, then an optional integer
1664 offset, and the closing > character. Pretty-printing box type is one
1665 of h , v , hv , b , or hov . ' h ' stands for an 'horizontal'
1666 pretty-printing box, ' v ' stands for a 'vertical' pretty-printing box,
1667 ' hv ' stands for an 'horizontal/vertical' pretty-printing box, ' b '
1668 stands for an 'horizontal-or-vertical' pretty-printing box demonstrat‐
1669 ing indentation, ' hov ' stands a simple 'horizontal-or-vertical'
1670 pretty-printing box. For instance, @[<hov 2> opens an 'horizon‐
1671 tal-or-vertical' pretty-printing box with indentation 2 as obtained
1672 with open_hovbox 2 . For more details about pretty-printing boxes, see
1673 the various box opening functions open_*box .
1674 - @] : close the most recently opened pretty-printing box.
1676 - @, : output a 'cut' break hint, as with print_cut () .
1678 - @ : output a 'space' break hint, as with print_space () .
1680 - @; : output a 'full' break hint as with print_break . The nspaces and
1682 offset parameters of the break hint may be optionally specified with
1683 the following syntax: the < character, followed by an integer nspaces
1684 value, then an integer offset , and a closing > character. If no pa‐
1685 rameters are provided, the good break defaults to a 'space' break hint.
1686 - @. : flush the pretty-printer and split the line, as with print_new‐
1688 line () .
1689 - @<n> : print the following item as if it were of length n . Hence,
1691 printf "@<0>%s" arg prints arg as a zero length string. If @<n> is not
1692 followed by a conversion specification, then the following character of
1693 the format is printed as if it were of length n .
1694 - @{ : open a semantic tag. The name of the tag may be optionally spec‐
1696 ified with the following syntax: the < character, followed by an op‐
1697 tional string specification, and the closing > character. The string
1698 specification is any character string that does not contain the closing
1699 character '>' . If omitted, the tag name defaults to the empty string.
1700 For more details about semantic tags, see the functions For‐
1701 mat.open_stag and Format.close_stag .
1702 - @} : close the most recently opened semantic tag.
1704 - @? : flush the pretty-printer as with print_flush () . This is
1706 equivalent to the conversion %! .
1707 - @\n : force a newline, as with force_newline () , not the normal way
1709 of pretty-printing, you should prefer using break hints inside a verti‐
1710 cal pretty-printing box.
1711 Note: To prevent the interpretation of a @ character as a pretty-print‐
1713 ing indication, escape it with a % character. Old quotation mode @@ is
1714 deprecated since it is not compatible with formatted input interpreta‐
1715 tion of character '@' .
1716 Example: printf "@[%s@ %d@]@." "x =" 1 is equivalent to open_box ();
1718 print_string "x ="; print_space ();
1719 print_int 1; close_box (); print_newline () . It prints x = 1
1720 within a pretty-printing 'horizontal-or-vertical' box.
1721 val printf : ('a, formatter, unit) format -> 'a
1723 Same as fprintf above, but output on std_formatter .
1725 val eprintf : ('a, formatter, unit) format -> 'a
1729 Same as fprintf above, but output on err_formatter .
1731 val sprintf : ('a, unit, string) format -> 'a
1735 Same as printf above, but instead of printing on a formatter, returns a
1737 string containing the result of formatting the arguments. Note that
1738 the pretty-printer queue is flushed at the end of each call to sprintf
1739 .
1740 In case of multiple and related calls to sprintf to output material on
1742 a single string, you should consider using fprintf with the predefined
1743 formatter str_formatter and call flush_str_formatter () to get the fi‐
1744 nal result.
1745 Alternatively, you can use Format.fprintf with a formatter writing to a
1747 buffer of your own: flushing the formatter and the buffer at the end of
1748 pretty-printing returns the desired string.
1749 val asprintf : ('a, formatter, unit, string) format4 -> 'a
1753 Same as printf above, but instead of printing on a formatter, returns a
1755 string containing the result of formatting the arguments. The type of
1756 asprintf is general enough to interact nicely with %a conversions.
1757 Since 4.01.0
1760 val dprintf : ('a, formatter, unit, formatter -> unit) format4 -> 'a
1764 Same as Format.fprintf , except the formatter is the last argument.
1766 dprintf "..." a b c is a function of type formatter -> unit which can
1767 be given to a format specifier %t .
1768 This can be used as a replacement for Format.asprintf to delay format‐
1770 ting decisions. Using the string returned by Format.asprintf in a for‐
1771 matting context forces formatting decisions to be taken in isolation,
1772 and the final string may be created prematurely. Format.dprintf allows
1773 delay of formatting decisions until the final formatting context is
1774 known. For example:
1775 let t = Format.dprintf "%i@ %i@ %i" 1 2 3 in
1776 ...
1777 Format.printf "@[<v>%t@]" t
1778 Since 4.08.0
1782 val ifprintf : formatter -> ('a, formatter, unit) format -> 'a
1786 Same as fprintf above, but does not print anything. Useful to ignore
1788 some material when conditionally printing.
1789 Since 3.10.0
1792 Formatted Pretty-Printing with continuations.
1797 val kfprintf : (formatter -> 'a) -> formatter -> ('b, formatter, unit,
1799 'a) format4 -> 'b
1800 Same as fprintf above, but instead of returning immediately, passes the
1802 formatter to its first argument at the end of printing.
1803 val kdprintf : ((formatter -> unit) -> 'a) -> ('b, formatter, unit, 'a)
1807 format4 -> 'b
1808 Same as Format.dprintf above, but instead of returning immediately,
1810 passes the suspended printer to its first argument at the end of print‐
1811 ing.
1812 Since 4.08.0
1815 val ikfprintf : (formatter -> 'a) -> formatter -> ('b, formatter, unit,
1819 'a) format4 -> 'b
1820 Same as kfprintf above, but does not print anything. Useful to ignore
1822 some material when conditionally printing.
1823 Since 3.12.0
1826 val ksprintf : (string -> 'a) -> ('b, unit, string, 'a) format4 -> 'b
1830 Same as sprintf above, but instead of returning the string, passes it
1832 to the first argument.
1833 val kasprintf : (string -> 'a) -> ('b, formatter, unit, 'a) format4 ->
1837 'b
1838 Same as asprintf above, but instead of returning the string, passes it
1840 to the first argument.
1841 Since 4.03
1844 Deprecated
1849 val bprintf : Buffer.t -> ('a, formatter, unit) format -> 'a
1850 Deprecated. This function is error prone. Do not use it. This func‐
1852 tion is neither compositional nor incremental, since it flushes the
1853 pretty-printer queue at each call.
1854 If you need to print to some buffer b , you must first define a format‐
1856 ter writing to b , using let to_b = formatter_of_buffer b ; then use
1857 regular calls to Format.fprintf with formatter to_b .
1858 val kprintf : (string -> 'a) -> ('b, unit, string, 'a) format4 -> 'b
1862 Deprecated. An alias for ksprintf .
1864 val set_all_formatter_output_functions : out:(string -> int -> int ->
1868 unit) -> flush:(unit -> unit) -> newline:(unit -> unit) -> spaces:(int
1869 -> unit) -> unit
1870 Deprecated. Subsumed by set_formatter_out_functions .
1872 val get_all_formatter_output_functions : unit -> (string -> int -> int
1876 -> unit) * (unit -> unit) * (unit -> unit) * (int -> unit)
1877 Deprecated. Subsumed by get_formatter_out_functions .
1879 val pp_set_all_formatter_output_functions : formatter -> out:(string ->
1883 int -> int -> unit) -> flush:(unit -> unit) -> newline:(unit -> unit)
1884 -> spaces:(int -> unit) -> unit
1885 Deprecated. Subsumed by pp_set_formatter_out_functions .
1887 val pp_get_all_formatter_output_functions : formatter -> unit ->
1891 (string -> int -> int -> unit) * (unit -> unit) * (unit -> unit) * (int
1892 -> unit)
1893 Deprecated. Subsumed by pp_get_formatter_out_functions .
1895 String tags
1900 val pp_open_tag : formatter -> tag -> unit
1901 Deprecated. Subsumed by Format.pp_open_stag .
1903 val open_tag : tag -> unit
1907 Deprecated. Subsumed by Format.open_stag .
1909 val pp_close_tag : formatter -> unit -> unit
1913 Deprecated. Subsumed by Format.pp_close_stag .
1915 val close_tag : unit -> unit
1919 Deprecated. Subsumed by Format.close_stag .
1921 type formatter_tag_functions = {
1924 mark_open_tag : tag -> string ;
1925 mark_close_tag : tag -> string ;
1926 print_open_tag : tag -> unit ;
1927 print_close_tag : tag -> unit ;
1928 }
1929 Deprecated. Subsumed by Format.formatter_stag_functions .
1932 val pp_set_formatter_tag_functions : formatter -> formatter_tag_func‐
1936 tions -> unit
1937 Deprecated. Subsumed by Format.pp_set_formatter_stag_functions .
1939 This function will erase non-string tag formatting functions.
1942 val set_formatter_tag_functions : formatter_tag_functions -> unit
1946 Deprecated. Subsumed by Format.set_formatter_stag_functions .
1948 val pp_get_formatter_tag_functions : formatter -> unit -> format‐
1952 ter_tag_functions
1953 Deprecated. Subsumed by Format.pp_get_formatter_stag_functions .
1955 val get_formatter_tag_functions : unit -> formatter_tag_functions
1959 Deprecated. Subsumed by Format.get_formatter_stag_functions .
1961OCamldoc 2022-07-22 Format(3)