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
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
|
% \iffalse meta-comment
%
%% File: xfrac.dtx
%
% Copyright (C) 2004,2008-2010 Morten Hoegholm
% (C) 2011,2012,2014-2024 The LaTeX Project
%
% It may be distributed and/or modified under the conditions of the
% LaTeX Project Public License (LPPL), either version 1.3c of this
% license or (at your option) any later version. The latest version
% of this license is in the file
%
% https://www.latex-project.org/lppl.txt
%
% This file is part of the "xfrac package" (The Work in LPPL)
% and all files in that bundle must be distributed together.
%
% -----------------------------------------------------------------------
%
% The development version of the bundle can be found at
%
% https://github.com/latex3/xfrac
%
% for those people who are interested.
%
%<*driver|package>
\RequirePackage{amstext,graphicx}
%</driver|package>
%<*driver>
\documentclass[full]{l3doc}
\usepackage{nicefrac,xfrac} ^^A Need nicefrac for demo purposes
\providecommand*\key[1]{\textbf{#1}}
\newcommand*\switch[2]{{\fontfamily{#1}\selectfont #2}}
\begin{document}
\DocInput{\jobname.dtx}
\end{document}
%</driver>
% \fi
%
% \title{^^A
% The \pkg{xfrac} package\\ Split-level fractions^^A
% }
%
% \author{^^A
% The \LaTeX{} Project\thanks
% {^^A
% E-mail:
% \href{mailto:latex-team@latex-project.org}
% {latex-team@latex-project.org}^^A
% }^^A
% }
%
% \date{Released 2024-06-04}
%
% \maketitle
%
% \begin{documentation}
%
% The \pkg{xfrac} package defines a document command \cs{sfrac}
% with the following syntax:
% \begin{quote}
% \cs{sfrac}\oarg{instance}\marg{num}\oarg{sep}\marg{denom}
% \end{quote}
% Let's show a few examples:
% \begin{verbatim}
% \sfrac{1}{2}, $\sfrac{1}{2}$,
% $\mathbf{3\times\sfrac{1}{2}}$
% \quad \fontfamily{ppl}\selectfont Palatino: \sfrac{1}{2}
% \quad \fontfamily{ptm}\selectfont Times: \sfrac{1}{2}
% \end{verbatim}
% \begin{quote}
% \sfrac{1}{2}, $\sfrac{1}{2}$, $\mathbf{3\times\sfrac{1}{2}}$
% \quad \fontfamily{ppl}\selectfont Palatino: \sfrac{1}{2}
% \quad \fontfamily{ptm}\selectfont Times: \sfrac{1}{2}
% \end{quote}
% You'll notice something interesting: not only does the \cs{sfrac}
% command work as it should in math mode, it also gets the job done
% for other fonts as well.
%
% \section{A Bit of History}
%
% \subsection{The Past}
%
% One of the first exercises in \emph{The \TeX{}Book} is to design a
% macro for split level fractions. The solution presented is fairly
% simple, using a \emph{virgule} (a slash) for separating the two
% components. It looks okay because the text font and math font of
% Computer Modern look almost identical.
%
% The proper symbol to use instead of the virgule is a \emph{solidus}
% which does not exist in Computer Modern. It is however available in
% the European Computer Modern fonts, but I'll get back to that.
%
% \subsection{The Present}
%
% The most common way to produce split level fractions within \LaTeXe{}
% is by means of the \pkg{nicefrac} package. Part of the reason it
% has found widespread use is due to the strange design of the
% built-in text fractions of the EC fonts, which look like this:
% \textonehalf{}. The package is very simple to use but there are a few
% issues:
% \begin{itemize}
% \item It uses the virgule instead of the solidus.
% \item Font size of numerator and denominator is bigger than in the
% built-in symbol. Compare Palatino: \switch{ppl}{\nicefrac{1}{2}}
% \emph{vs.}~\switch{ppl}{\textonehalf}.
% \item It doesn't correct for fonts using text figures such as in the
% \pkg{eco} package. Compare \switch{cmor}{\nicefrac{1}{2}} and
% \switch{cmor}{\nicefrac{8}{9}}.
% \item In math mode, it doesn't always pick up the correct math
% alphabet.
% \end{itemize}
% In short: \pkg{nicefrac} doesn't attempt to be the answer to
% everything and so this is not a criticism of the package. It works
% quite well for Computer Modern which was pretty much what was widely
% available at the time it was developed. Users these days, however,
% have a choice of many fonts when they write their documents.
%
% \subsection{The Future}
%
% Fonts are wildly different; one macro that works fine for Computer
% Modern obviously doesn't work well at all in Palatino. For one we
% have to make the separator symbol configurable, and we need to
% take care of several details as well: font scaling of the
% numerator/denominator pair (ND), font selection of ND, \emph{etc.} If we
% are to have a single package for this in the future we have to define a
% totally generic interface for the fraction commands and then adjust
% parameters depending on the current font. What you see in this
% prototype implementation of \pkg{xfrac} is just that.
%
% \section{Advanced User Interface}
%
% \subsection{Text mode}
%
% The usual problem in text mode has a name: Computer Modern. The
% solidi of all the Computer Modern fonts leave a lot to be desired,
% although things are potentially looking better as the Latin Modern
% fonts are becoming more stable and widespread. As long as the
% default fonts are Computer Modern variants we must however work
% around this. One idea that comes to mind is to see what happens
% when you use a solidus from another font instead. Let's try with
% Times:
% \begin{quote}
% \DeclareInstance{xfrac}{cmr2}{text}
% {slash-symbol-font = ptm}
% \enquote{You take \sfrac[cmr2]{1}{2} cup of sugar, \ldots}
% \end{quote}
% That looks quite good actually, so it was probably very difficult
% to obtain that result. Nope, it was extremely easy---if you happen
% to know about \emph{instances}:
% \begin{verbatim}
% \DeclareInstance{xfrac}{cmr}{text}
% {slash-symbol-font = ptm}
% \end{verbatim}
% So we define an instance with the name |cmr| from the template
% |text| which in turn is of object type |xfrac|. You'll notice
% the |cmr| is also the name of the font family for Computer Modern
% Roman and the reasoning behind is that every font family should
% have it's own settings, and if a document command is to work well
% in that scheme, letting it use the name of the current font family
% seems like a good idea. Thus the \cs{sfrac} command checks to see
% whether an instance with same name as the current font family
% exists and uses it if the test is true; otherwise the default
% setting is used. Here we defined the instance to be used for the
% font family |cmr| and just told it to use the Times font for
% typesetting the slash symbol which turns out to be a solidus by
% default.
%
% The option \texttt{cm-recommended} which is loaded by default uses
% the Times solidus for Computer Modern Roman and Computer Modern
% Sans Serif and the Palatino solidus for Computer Modern Typewriter
% Type. This looks quite good. Should you however not want this you
% can use the option \texttt{cm-standard} which produces somewhat
% acceptable results using Computer Modern exclusively.
%
% So what about old style figures? If you use the \pkg{eco}
% package you might define an instance similar to this (`cmor' is
% the name of the roman font activated by \pkg{eco}):
% \DeclareInstance{xfrac}{cmor}{text}
% {
% slash-symbol-font = ptm,
% numerator-font = cmr,
% denominator-font = cmr
% }
% \begin{verbatim}
% \DeclareInstance{xfrac}{cmor}{text}
% {
% slash-symbol-font = ptm,
% numerator-font = cmr,
% denominator-font = cmr
% }
% \end{verbatim}
% We also use regular Computer Modern Roman for typesetting ND, so
% we end up with \switch{cmor}{\sfrac{1}{2}} and
% \switch{cmor}{\sfrac{8}{9}} instead of
% \switch{cmor}{\nicefrac{1}{2}} and \switch{cmor}{\nicefrac{8}{9}}.
% Much better.
%
% There are also situations where other tricks are useful. If you
% don't have the inferior and superior figures available in a font,
% or the font doesn't have a wider design for small font sizes, you
% can cheat by manually scaling the ND-pair. I got nice results for
% Adobe's Stempel Garamond (with small caps and old style figures)
% with the following setup:
% \begin{verbatim}
% \DeclareInstance{xfrac}{pegj}{text}
% {
% numerator-font = pegx,
% denominator-font = pegx,
% scale-factor = 0.9,
% h-scale = 1.1
% }
% \end{verbatim}
% We use the font family |pegx| (Stempel Garamond with real small
% caps) for typesetting the ND-pair. Additionally the key
% \key{scale-factor} specifies that the font size used for the
% ND-pair should be $0.9$ of the height of the solidus, and the key
% \key{h-scale} specifies that the ND-pair should be scaled an extra
% 10\,\% horizontally.
%
% Should you be so fortunate the have a font with inferior and
% superior figures like in the Monotype Janson example from Philipp
% Lehman's excellent \emph{The Font Installation Guide}. In that
% example Philipp defines the font families |mjn0| for the inferior
% figures and |mjn1| for the superior. Thus to get the \cs{sfrac}
% command to use them on the fly for the font family |mjnj| (Janson,
% old style figures) we would say
% \begin{verbatim}
% \DeclareInstance{xfrac}{mjnj}{text}
% {
% numerator-font = mjn1,
% denominator-font = mjn0,
% scaling = false,
% numerator-bot-sep = 0 pt,
% denominator-bot-sep = 0 pt
% }
% \end{verbatim}
% I think this example is a very clean way to do it. An alternative
% approach could be to use the keys \key{numerator-format} and
% \key{denominator-format} to process the arguments and let them
% determine what to do.
%
% \subsection{Math Mode}
%
% In math mode the choices are a lot fewer because first of all
% \TeX{} comes with a built-in limitation of $16$ math families.
% Additionally we will not need a solidus for typesetting split
% fractions in math, as tradition is to use a virgule instead. We
% define the basic |mathdefault| instance to simply use the math
% family in use when the instance is run. So if we're in normal math
% like |$\sfrac{7}{9}$| we simply get family~$-1$. If we're inside a
% \cs{mathbf} we're in family~$4$ (in the standard setup at least),
% and so the fraction is typeset with the same math family. Simple,
% isn't?
%
% You can also declare instances for the math families, but I really
% don't see why you would. If you do then name them according to the
% scheme \texttt{mathfam\meta{N}}, where \meta{N} is the family number, and
% only do it if you \emph{really} know how to set up math fonts.
% That is, if \cs{DeclareMathAlphabet} is unbeknownst to you, then
% just don't go there.
%
% \section{The Template Interface}
%
% \begin{TemplateInterfaceDescription}{xfrac}
%
% \TemplateArgument{1}{The numerator}
%
% \TemplateArgument{2}{The separator}
%
% \TemplateArgument{3}{The denominator}
%
% \TemplateSemantics
%
% Typesets arguments 1 and 3 separated by argument 2, which in text
% mode by default is a \emph{solidus}. This is taken from
% \pkg{textcomp} where it is denoted \cs{textfractionsolidus}.
% This is the character used for the ready made split level
% fractions such as \textonehalf{}---except in the (European) Computer
% Modern fonts. In math mode a \emph{virgule} is used instead as
% this is more appropriate and it is always available in the math
% fonts. The solidus is a text symbol only.
%
% \end{TemplateInterfaceDescription}
%
% \begin{TemplateDescription}{xfrac}{text}
%
% \TemplateKey{numerator-font}{tokenlist}
% {Font family specification to use for the numerator.}
% {\cs{f@family}}
%
% \TemplateKey{numerator-format}{function 1 arg}
% {Action to be taken on the numerator.}
% {Process argument unchanged}
%
% \TemplateKey{slash-symbol}{tokenlist}
% {The separator symbol. If not specified the default value will be
% used instead.}
% {Solidus (\cs{textfractionsolidus})}
%
% \TemplateKey{slash-symbol-font}{tokenlist}
% {Font family specification to use for the separator symbol.}
% {\cs{f@family}}
%
% \TemplateKey{slash-symbol-format}{function 1 arg}
% {Action to be taken on the separator symbol.}
% {Process argument unchanged}
%
% \TemplateKey{denominator-font}{tokenlist}
% {Font family specification to use for the denominator.}
% {\cs{f@family}}
%
% \TemplateKey{denominator-format}{function 1 arg}
% {Action to be taken on the denominator.}
% {Process argument unchanged}
%
% \TemplateKey{h-scale}{real}
% {Factor by which the numerator and denominator should be
% horizontally scaled. It should only be used if the real superior
% and inferior fonts are not available. For instance Stempel
% Garamond looks excellent if scaled 10\,\% extra horizontally, \emph{i.e.},
% by a factor of 1.1.}
% {1}
%
% \TemplateKey{v-scale}{real}
% {Same as \key{h-scale} only vertically. Probably not of much use
% but added for completeness.}
% {1}
%
% \TemplateKey{scale-factor}{real}
% {Fraction of the size of \key{slash-symbol}. Used for setting the
% font size of numerator and denominator. Usually a value of app.\
% \sfrac{5}{6} produces fine results. It should only be used if the
% real superior and inferior fonts are not available. As an example
% Stempel Garamond looks better if the factor is 0.9.}
% {0.83333}
%
% \TemplateKey{scale-relative}{choice}
% {If set to |true| the font size of the numerator and denominator
% is scaled with respect to the height of the \key{slash-symbol}. If
% set to |false| the font is scaled with respect to the total height
% of the \key{slash-symbol}.}
% {true}
%
% \TemplateKey{scaling}{choice}
% {If set to |true| the fonts are allowed to scale. If set to
% |false| they are not. See the `Janson' example for an application.}
% {true}
%
% \TemplateKey{numerator-top-sep}{length}
% {Dimension specifying the space between the top of the
% \key{slash-symbol} and the top of the numerator. If not specified,
% the depth of the solidus will be used, because this value will
% make the fraction look even.}
% {Unspecified}
%
% \TemplateKey{numerator-bot-sep}{length}
% {Dimension specifying the lift of the numerator from the
% baseline.}
% {Unspecified}
%
% \TemplateKey{denominator-bot-sep}{length}
% {Dimension specifying the lift of the denominator from the
% baseline.}
% {Unspecified}
%
% \TemplateKey{slash-right-kern}{length}
% {Dimension specifying the kerning between the \key{slash-symbol}
% and the numerator.}
% {\texttt{0pt}}
%
% \TemplateKey{slash-left-kern}{length}
% {Dimension specifying the kerning between the \key{slash-symbol}
% and the denominator.}
% {\texttt{0pt}}
%
% \TemplateKey{math-mode}{choice}
% {Are we in math mode or not?}
% {false}
%
% \TemplateKey{phantom}{tokenlist}
% {A character that suits the common cases. As we would mostly want
% to use numbers in text mode we choose a \enquote{tall} number, while in
% math it is somewhat different.}
% {8}
%
% \TemplateSemantics
%
% This template is also the foundation for the \enquote{math} template. The
% keys \key{slash-right-mkern} and \key{slash-left-mkern} can only
% be used in math mode and are not shown here.
%
% \end{TemplateDescription}
%
% \begin{TemplateDescription}{xfrac}{math}
%
% \TemplateKey{numerator-font}{tokenlist}
% {Font family specification to use for the numerator.}
% {\cs{number}\cs{fam}}
%
% \TemplateKey{slash-symbol}{tokenlist}
% {The separator symbol. If not specified the default value will be
% used instead.}
% {Virgule ($/$)}
%
% \TemplateKey{slash-symbol-font}{tokenlist}
% {Font family specification to use for the separator symbol.}
% {\cs{number}\cs{fam}}
%
% \TemplateKey{denominator-font}{tokenlist}
% {Font family specification to use for the denominator.}
% {\cs{number}\cs{fam}}
%
% \TemplateKey{scale-factor}{real}
% {Fraction of the size of \key{slash-symbol}. In math mode we
% cannot rely on the fonts to be able to scale, but giving a default
% scale of 0.7 fits into the regular size changing scheme---the
% default scheme has values $(D,T,S,SS)=(1,1,0.7,0.5)$ whereas we
% with a default \key{scale-factor} of 0.7 get $(1,1,0.7,0.49)$.
% That's close enough.}
% {0.7}
%
% \TemplateKey{scale-relative}{choice}
% {If set to |true| the font size of the numerator and denominator
% is scaled with respect to the height of the \key{slash-symbol}. If
% set to |false| the font is scaled with respect to the total height
% of the \key{slash-symbol}.}
% {false}
%
% \TemplateKey{scaling}{choice}
% {If set to |true| the fonts are allowed to scale. If set to
% |false| they are not. See the |plainmath| example for an application.}
% {true}
%
% \TemplateKey{numerator-top-sep}{length}
% {Dimension specifying the space between the top of the
% \key{slash-symbol} and the top of the numerator. If not specified,
% the depth of the virgule will be used, because this value will
% make the fraction look even.}
% {\texttt{0pt}}
%
% \TemplateKey{denominator-bot-sep}{length}
% {Dimension specifying the lift of the denominator from the
% baseline.}
% {\texttt{0pt}}
%
% \TemplateKey{slash-right-mkern}{muskip}
% {Same as \key{slash-right-kern} but for math mode only and should
% be specified in \texttt{mu} units.}
% {\texttt{-2mu}}
%
% \TemplateKey{slash-left-mkern}{muskip}
% {Same as \key{slash-left-kern} but for math mode only and should
% be specified in \texttt{mu} units.}
% {\texttt{-1mu}}
%
% \TemplateKey{math-mode}{choice}
% {Are we in math mode or not?}
% {true}
%
% \TemplateKey{phantom}{tokenlist}
% {A character that suits the common cases. In math we have a high
% risk of using a parenthesis, so we choose that. Text mode is
% another story.}
% {(^^A)
% }
%
% \TemplateSemantics
%
% This template is a restricted version of the |text| template. Only
% the keys that are different from the |text| template are shown
% here. Also bear in mind that the attributes \key{slash-left-kern}
% and \key{slash-right-kern} have no meaning in this template.
%
% \end{TemplateDescription}
%
% \end{documentation}
%
% \begin{implementation}
%
% \section{\pkg{xfrac} implementation}
%
% \begin{macrocode}
%<*package>
% \end{macrocode}
%
% \begin{macrocode}
%<@@=xfrac>
% \end{macrocode}
%
% Load \pkg{expl3} \enquote{up-front} only if required.
% \begin{macrocode}
\@ifundefined{ExplLoaderFileDate}
{\RequirePackage{expl3}}
{}
% \end{macrocode}
%
% Make sure that the version of \pkg{l3kernel} in use is sufficiently new.
% We use \cs{ExplFileDate} as \cs{@ifpackagelater} doesn't work for pre-loaded
% \pkg{expl3} in the absence of the package.
% \begin{macrocode}
\@ifl@t@r\ExplLoaderFileDate{2018-02-21}
{}
{%
\PackageError{xfrac}{Support package expl3 too old}
{%
You need to update your installation of 'l3kernel'.\MessageBreak
Loading~xfrac~will~abort!%
}%
\endinput
}%
% \end{macrocode}
%
% \begin{macrocode}
\ProvidesExplPackage{xfrac}{2024-06-04}{}
{Split-level fractions}
% \end{macrocode}
%
% \begin{macro}{\IfFormatAtLeastTF}
% Not present in older kernels: use the \LaTeXe{} mechanism as this is correct
% for this case.
% \begin{macrocode}
\providecommand \IfFormatAtLeastTF { \@ifl@t@r \fmtversion }
% \end{macrocode}
% \end{macro}
%
% \begin{macrocode}
\IfFormatAtLeastTF { 2020-02-02 }
{ }
{ \RequirePackage { textcomp } }
% \end{macrocode}
%
% \begin{macrocode}
\IfFormatAtLeastTF { 2020-10-01 }
{ }
{ \RequirePackage { xparse } }
% \end{macrocode}
%
% \begin{variable}{\l_@@_cm_std_bool}
% There is one option to support.
% \begin{macrocode}
\keys_define:nn { xfrac }
{
cm-recommended .choice:,
cm-recommended /
false .code:n =
{ \bool_set_true:N \l_@@_cm_std_bool },
cm-recommended /
true .code:n =
{ \bool_set_false:N \l_@@_cm_std_bool },
cm-recommended .default:n = { true },
cm-standard .bool_set:N = \l_@@_cm_std_bool
}
% \end{macrocode}
% \end{variable}
%
% \begin{macrocode}
\IfFormatAtLeastTF { 2022-06-01 }
{ \ProcessKeyOptions }
{
\RequirePackage { l3keys2e }
\ProcessKeysOptions { xfrac }
}
% \end{macrocode}
%
% \begin{macrocode}
\IfFormatAtLeastTF { 2024-06-01 }
{ }
{ \RequirePackage { xtemplate } }
\cs_if_exist:NF \IfInstanceExistsTF
{ \cs_new_eq:NN \IfInstanceExistsTF \IfInstanceExistTF }
% \end{macrocode}
%
% \begin{variable}{\l_@@_slash_box}
% \begin{variable}{\l_@@_tmp_box}
% In keeping with the \LaTeX3 philosophy, rather than use generic
% scratch boxes and get confused, \pkg{xfrac} reserves its own named
% working space.
% \begin{macrocode}
\box_new:N \l_@@_slash_box
\box_new:N \l_@@_tmp_box
% \end{macrocode}
% \end{variable}
% \end{variable}
%
% \begin{macro}{\@@_tmp:w}
% Used for the raised boxes: weird as it does not take an argument
% but the \cs{raisebox} does.
% \begin{macrocode}
\cs_new:Npn \@@_tmp:w { }
% \end{macrocode}
% \end{macro}
%
%
% \subsection{Initialisation of variables}
%
% Variables used in templates have to be set up: there is not
% much to say about these, other than that they must exist.
%
% \begin{variable}{\l_@@_denominator_bot_sep_dim}
% \begin{variable}{\l_@@_numerator_bot_sep_dim}
% \begin{variable}{\l_@@_numerator_top_sep_dim}
% \begin{variable}{\l_@@_slash_left_sep_dim}
% \begin{variable}{\l_@@_slash_right_sep_dim}
% Fixed lengths.
% \begin{macrocode}
\dim_new:N \l_@@_denominator_bot_sep_dim
\dim_new:N \l_@@_numerator_bot_sep_dim
\dim_new:N \l_@@_numerator_top_sep_dim
\dim_new:N \l_@@_slash_left_sep_dim
\dim_new:N \l_@@_slash_right_sep_dim
% \end{macrocode}
% \end{variable}
% \end{variable}
% \end{variable}
% \end{variable}
% \end{variable}
%
% \begin{variable}{\l_@@_slash_left_muskip}
% \begin{variable}{\l_@@_slash_right_muskip}
% Math mode skips.
% \begin{macrocode}
\muskip_new:N \l_@@_slash_left_muskip
\muskip_new:N \l_@@_slash_right_muskip
% \end{macrocode}
% \end{variable}
% \end{variable}
%
% \begin{variable}{\l_@@_hscale_fp}
% \begin{variable}{\l_@@_scale_factor_fp}
% \begin{variable}{\l_@@_vscale_fp}
% Floating point values.
% \begin{macrocode}
\fp_new:N \l_@@_hscale_fp
\fp_new:N \l_@@_scale_factor_fp
\fp_new:N \l_@@_vscale_fp
% \end{macrocode}
% \end{variable}
% \end{variable}
% \end{variable}
%
% \begin{variable}{\l_@@_denominator_font_tl}
% \begin{variable}{\l_@@_numerator_font_tl}
% \begin{variable}{\l_@@_phantom_tl }
% \begin{variable}{\l_@@_slash_symbol_tl}
% \begin{variable}{\l_@@_slash_symbol_font_tl}
% Token lists, which include floating-point numbers and math(s)
% skips.
% \begin{macrocode}
\tl_new:N \l_@@_denominator_font_tl
\tl_new:N \l_@@_numerator_font_tl
\tl_new:N \l_@@_phantom_tl
\tl_new:N \l_@@_slash_symbol_tl
\tl_new:N \l_@@_slash_symbol_font_tl
% \end{macrocode}
% \end{variable}
% \end{variable}
% \end{variable}
% \end{variable}
% \end{variable}
%
% \begin{macro}{\@@_fontscale:}
% \begin{macro}{\@@_math:n}
% \begin{macro}{\@@_denominator_font_change:}
% \begin{macro}{\@@_denominator_format:n}
% \begin{macro}{\@@_numerator_font_change:}
% \begin{macro}{\@@_numerator_format:n}
% \begin{macro}{\@@_relscale:}
% \begin{macro}{\@@_slash_symbol_font_change:}
% \begin{macro}{\@@_slash_symbol_format:n}
% \begin{macro}{\@@_text_or_math:n}
% Functions, either things which are calculated \enquote{on the fly}
% (no argument required) or are functions taking one argument in the
% code.
% \begin{macrocode}
\cs_new:Npn \@@_fontscale: { }
\cs_new:Npn \@@_math:n #1 { }
\cs_new:Npn \@@_denominator_font_change: { }
\cs_new:Npn \@@_denominator_format:n #1 { }
\cs_new:Npn \@@_numerator_font_change: { }
\cs_new:Npn \@@_numerator_format:n #1 { }
\cs_new:Npn \@@_relscale: { }
\cs_new:Npn \@@_slash_symbol_font_change: { }
\cs_new:Npn \@@_slash_symbol_format:n #1 { }
\cs_new:Npn \@@_text_or_math:n #1 { }
% \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
%
% \subsection{The template}
%
% There is only one object type in \pkg{xfrac}, rather unimaginatively
% named \texttt{xfrac}.
% \begin{macrocode}
\IfFormatAtLeastTF { 2024-06-01 }
{ \NewTemplateType }
{ \DeclareObjectType }
{ xfrac } { 3 }
% \end{macrocode}
%
% A single template interface is used for both text and math(s), which
% does make a few things a little complex later.
% \begin{macrocode}
\DeclareTemplateInterface { xfrac } { text } { 3 }
{
denominator-bot-sep : length = \c_max_dim ,
denominator-font : tokenlist = \f@family ,
denominator-format : function 1 = #1 ,
h-scale : real = 1 ,
math-mode : choice { false , true }
= false ,
numerator-font : tokenlist = \f@family ,
numerator-format : function 1 = #1 ,
numerator-bot-sep : length = \c_max_dim ,
numerator-top-sep : length = \c_max_dim ,
phantom : tokenlist = 8 ,
scale-factor : real = 0.83333 ,
scale-relative : choice { false , true }
= true ,
scaling : choice { false , true }
= true ,
slash-left-kern : length = 0 pt ,
slash-left-mkern : muskip = -2 mu ,
slash-right-kern : length = 0 pt ,
slash-right-mkern : muskip = -1 mu ,
slash-symbol : tokenlist = \textfractionsolidus ,
slash-symbol-font : tokenlist = \f@family ,
slash-symbol-format : function 1 = #1 ,
v-scale : real = 1 ,
}
% \end{macrocode}
% Most of the variable binding is quite simple: of course, the choices
% are a little more complicated. That is particularly true where
% these have to set up \enquote{on the fly} functions.
% \begin{macrocode}
\DeclareTemplateCode { xfrac } { text } { 3 }
{
denominator-bot-sep = \l_@@_denominator_bot_sep_dim ,
denominator-font = \l_@@_denominator_font_tl ,
denominator-format = \@@_denominator_format:n ,
h-scale = \l_@@_hscale_fp ,
math-mode =
{
false = \cs_set_eq:NN \@@_math:n \use:n,
true = \cs_set_eq:NN \@@_math:n \ensuremath
},
numerator-font = \l_@@_numerator_font_tl ,
numerator-format = \@@_numerator_format:n ,
numerator-bot-sep = \l_@@_numerator_bot_sep_dim ,
numerator-top-sep = \l_@@_numerator_top_sep_dim ,
phantom = \l_@@_phantom_tl ,
scale-factor = \l_@@_scale_factor_fp ,
scale-relative =
{
false =
\cs_set:Npn \@@_relscale:
{
\dim_eval:n
{ \box_ht:N \l_@@_tmp_box + \box_dp:N \l_@@_tmp_box }
},
true =
\cs_set:Npn \@@_relscale:
{ \dim_eval:n { \box_ht:N \l_@@_slash_box } }
},
scaling =
{
false = \cs_set_eq:NN \@@_fontscale: \prg_do_nothing:,
true =
\cs_set:Npn \@@_fontscale:
{
\fontsize
{ \fp_to_dim:n { \l_@@_scale_factor_fp * \@@_relscale: } }
{ \c_zero_dim }
\selectfont
}
},
slash-left-kern = \l_@@_slash_left_sep_dim ,
slash-left-mkern = \l_@@_slash_left_muskip ,
slash-right-kern = \l_@@_slash_right_sep_dim ,
slash-right-mkern = \l_@@_slash_right_muskip ,
slash-symbol = \l_@@_slash_symbol_tl ,
slash-symbol-font = \l_@@_slash_symbol_font_tl ,
slash-symbol-format = \@@_slash_symbol_format:n ,
v-scale = \l_@@_vscale_fp
}
% \end{macrocode}
% The implementation part starts with applying all of the settings
% from above. The first part of the set up is then to determine
% whether the surroundings are text or math(s), and react accordingly.
% \begin{macrocode}
{
\mode_if_math:TF
{
\cs_set_eq:NN \@@_text_or_math:n \text
\cs_set:Npe \@@_denominator_font_change:
{ \tex_fam:D \l_@@_denominator_font_tl }
\cs_set:Npe \@@_numerator_font_change:
{ \tex_fam:D \l_@@_numerator_font_tl }
\cs_set:Npe \@@_slash_symbol_font_change:
{ \tex_fam:D \l_@@_slash_symbol_font_tl }
}
{
\cs_set_eq:NN \@@_text_or_math:n \mbox
\cs_set:Npn \@@_denominator_font_change:
{
\fontfamily { \l_@@_denominator_font_tl }
\selectfont
}
\cs_set:Npn \@@_numerator_font_change:
{
\fontfamily { \l_@@_numerator_font_tl }
\selectfont
}
\cs_set:Npn \@@_slash_symbol_font_change:
{
\fontfamily { \l_@@_slash_symbol_font_tl }
\selectfont
}
}
% \end{macrocode}
% Everything is now either inside \cs{text} or an \cs{mbox}, depending
% upon the surroundings. First, there are some boxes to set up.
% \begin{macrocode}
\@@_text_or_math:n
{
\m@th
\hbox_set:Nn \l_@@_tmp_box
{ \@@_math:n { \vphantom { ( ) } } }
\hbox_set:Nn \l_@@_slash_box
{
\@@_math:n
{
\@@_slash_symbol_format:n
{
\@@_math:n
{
\@@_slash_symbol_font_change:
\IfNoValueTF {#2}
{ \l_@@_slash_symbol_tl } {#2}
}
}
}
}
% \end{macrocode}
% Check on the numerator separator dimensions. The code starts with the
% assumption that neither has been given, as this can then be used to
% set up a default, which is also used when both values are set
% erroneously.
% \begin{macrocode}
\cs_set:Npn \@@_tmp:w
{
\raisebox
{
\dim_eval:n
{
\box_ht:N \l_@@_slash_box
- \box_dp:N \l_@@_slash_box
- \height
}
}
}
\dim_compare:nNnTF
{ \l_@@_numerator_top_sep_dim } = { \c_max_dim }
{
\dim_compare:nNnF
{ \l_@@_numerator_bot_sep_dim } = { \c_max_dim }
{
\cs_set:Npn \@@_tmp:w
{
\raisebox
{ \dim_use:N \l_@@_numerator_bot_sep_dim }
}
}
}
{
\dim_compare:nNnTF
{ \l_@@_numerator_bot_sep_dim } = { \c_max_dim }
{
\cs_set:Npn \@@_tmp:w
{
\raisebox
{
\dim_eval:n
{
\box_ht:N \l_@@_slash_box
- \dim_use:N \l_@@_numerator_top_sep_dim
- \height
}
}
}
}
{
\msg_error:nn { xfrac }
{ over-specified-numerator-sep }
}
}
% \end{macrocode}
% Typeset the numerator.
% \begin{macrocode}
\@@_tmp:w
{
\@@_fontscale:
\@@_numerator_format:n
{
\scalebox
{ \fp_use:N \l_@@_hscale_fp }
[ \fp_use:N \l_@@_vscale_fp ]
{
\@@_math:n
{
\@@_numerator_font_change:
{
\vphantom { \l_@@_phantom_tl }
#1
}
}
}
}
}
\@@_math:n
{ % THIS IS JUST WRONG!
\mode_if_math:TF
{ \tex_mskip:D \l_@@_slash_right_muskip }
{ \tex_hskip:D \l_@@_slash_right_sep_dim }
}
% \end{macrocode}
% Typeset the separator.
% \begin{macrocode}
\box_use:N \l_@@_slash_box
\@@_math:n
{
\mode_if_math:TF
{ \tex_mskip:D \l_@@_slash_left_muskip }
{ \tex_hskip:D \l_@@_slash_left_sep_dim }
}
% \end{macrocode}
% Typeset the denominator.
% \begin{macrocode}
\dim_compare:nNnTF
{ \l_@@_denominator_bot_sep_dim } = { \c_max_dim }
{
\cs_set:Npn \@@_tmp:w
{ \raisebox { - \box_dp:N \l_@@_slash_box } }
}
{
\cs_set:Npn \@@_tmp:w
{
\raisebox
{ \dim_use:N \l_@@_denominator_bot_sep_dim }
}
}
\@@_tmp:w
{
\@@_fontscale:
\@@_denominator_format:n
{
\scalebox
{ \fp_use:N \l_@@_hscale_fp }
[ \fp_use:N \l_@@_vscale_fp ]
{
\@@_math:n
{
\@@_denominator_font_change:
{
\vphantom { \l_@@_phantom_tl }
#3
}
}
}
}
}
}
}
% \end{macrocode}
%
% Since math(s) and text mode are wildly different entities we define a
% separate template for each. You already saw the \enquote{text}
% template, and here is the \enquote{math} template.
% \begin{macrocode}
\IfFormatAtLeastTF { 2024-06-01 }
{
\DeclareTemplateCopy { xfrac } { math } { text }
\EditTemplateDefaults { xfrac } { math }
}
{ \DeclareRestrictedTemplate { xfrac } { text } { math } }
{
numerator-font = \number \fam ,
slash-symbol = / ,
slash-symbol-font = \number \fam ,
denominator-font = \number \fam ,
scale-factor = 0.7 ,
scale-relative = false ,
scaling = true ,
denominator-bot-sep = 0 pt ,
math-mode = true ,
phantom = ( % )
}
% \end{macrocode}
%
%\subsection{The standard instances}
%
% For the default instances we just use the relevant templates with
% the default settings.
%
% The default \enquote{text} instance.
% \begin{macrocode}
\DeclareInstance { xfrac } { default } { text } { }
% \end{macrocode}
%
% The default \enquote{math(s)} instance. We annot set the
% |numerator-top-sep| in the restricted template above.
% \begin{macrocode}
\DeclareInstance { xfrac } { mathdefault } { math }
{ numerator-top-sep = 0pt }
% \end{macrocode}
%
% Default Computer Modern setup. Far from optimal, but better than
% nothing.
% \begin{macrocode}
\DeclareInstance { xfrac } { cmr } { text }
{
denominator-bot-sep = 0 pt ,
numerator-top-sep = 0.2 ex ,
slash-left-kern = -0.1 em ,
slash-right-kern = -0.1 em
}
\DeclareInstance { xfrac } { cmss } { text }
{
denominator-bot-sep = 0 pt ,
numerator-top-sep = 0.2 ex ,
slash-left-kern = -0.1 em ,
slash-right-kern = -0.1 em
}
\DeclareInstance { xfrac } { cmtt } { text }
{
denominator-bot-sep = 0 pt ,
numerator-top-sep = 0.2 ex ,
slash-left-kern = -0.1 em ,
slash-right-kern = -0.1 em
}
% \end{macrocode}
%
% We can do better for the Computer Modern fonts. For cmr and cmss
% we choose Times, and for cmtt use Palatino.
% \begin{macrocode}
\bool_if:NF \l_@@_cm_std_bool
{
\DeclareInstance { xfrac } { cmr } { text }
{ slash-symbol-font = ptm }
\DeclareInstance { xfrac } { cmss } { text }
{ slash-symbol-font = ptm }
\DeclareInstance { xfrac } { cmtt } { text }
{ slash-symbol-font = ppl }
}
% \end{macrocode}
%
% Things works slightly better with Latin Modern.
% \begin{macrocode}
\DeclareInstance { xfrac } { lmr } { text }
{
denominator-bot-sep = 0 pt ,
numerator-top-sep = 0.1 ex ,
slash-left-kern = -0.15 em ,
slash-right-kern = -0.15 em
}
\DeclareInstance { xfrac } { lmss } { text }
{
denominator-bot-sep = 0 pt ,
numerator-top-sep = 0 pt ,
slash-left-kern = -0.15 em ,
slash-right-kern = -0.15 em
}
\DeclareInstance { xfrac } { lmtt } { text }
{
denominator-bot-sep = 0 pt ,
numerator-top-sep = 0 pt ,
slash-left-kern = -0.15 em ,
slash-right-kern = -0.15 em
}
% \end{macrocode}
%
% \subsection{The user command}
%
% \begin{macro}{\sfrac}
% Currently there is just a single user command. \cs{sfrac} takes
% two mandatory arguments: numerator and denominator. It can take an
% optional argument between the mandatory specifying the separator
% like this:
% \begin{verbatim}
% \sfrac{7}[/]{12}
% \end{verbatim}
% It also has an optional argument that comes before the first
% mandatory argument. If used it will use that instance instead of
% the auto-detected one, so a user who has defined the instance
% \enquote{cmr2} may use
% \begin{verbatim}
% \sfrac[cmr2]{7}{12}
% \end{verbatim}
% and get the settings from \enquote{cmr2} instead of the settings of
% the current font family.
% \begin{macrocode}
\NewDocumentCommand \sfrac { o m o m }
{
\mode_if_math:TF
{
\IfInstanceExistsTF { xfrac } { mathfam \number \fam }
{ \UseInstance { xfrac } { mathfam \number \fam } }
{ \UseInstance { xfrac } { mathdefault } }
{#2} {#3} {#4}
}
{
\IfInstanceExistsTF { xfrac } {#1}
{ \UseInstance { xfrac } {#1} }
{
\IfInstanceExistsTF { xfrac } { \f@family }
{ \UseInstance { xfrac } { \f@family } }
{ \UseInstance { xfrac } { default } }
}
{#2} {#3} {#4}
}
}
% \end{macrocode}
% \end{macro}
%
% \subsection{Messages}
%
% Just the one.
% \begin{macrocode}
\msg_new:nnnn { xfrac } { over-specified-numerator-sep }
{ You~have~specified~both~"numerator-top-sep"~and~"numerator-bot-sep". }
{ I~will~pretend~that~you~didn't~specify~either~of~them. }
% \end{macrocode}
%
% \begin{macrocode}
%</package>
% \end{macrocode}
%
% \end{implementation}
%
% \PrintIndex
|