TODO revision 75584
1A line prefix request to make e.g. French quotation possible:
2
3  He said: >> blablablabla
4  >> blablabla blabla  bla
5  >> blabla blabla bla bla
6  >> bla bla bla blablabla
7  >> blabla. <<
8
9Give a more helpful error message when the indent is set to a value
10greater than the line-length.
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12Tracing. This is a pain to implement because requests are responsible
13for reading their own arguments.
14
15Possibly implement -s option (stop every N pages). This functionality
16would be more appropriate in a postprocessor.
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18Line breaking should be smarter.  In particular, it should be possible
19to shrink spaces.  Also avoid having a line that's been shrunk a lot
20next to a line that's been stretched a lot.  The difficulty is to
21design a mechanism that allows the user complete control over the
22decision of where to break the line.
23
24Provide a mechanism to control the shape of the rag in non-justified
25text.
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27Add a discretionary break escape sequence. \='...'...'...' like TeX.
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29Think about kerning between characters and spaces. (Need to implement
30get_breakpoints and split methods for kern_pair_node class.)
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32In troff, if .L > 1 when a diversion is reread in no-fill mode, then
33extra line-spacing is added on. Groff at the moment treats line-spacing
34like vertical spacing and doesn't do this. 
35
36Suppose \(ch comes from a special font S, and that the current font is
37R. Suppose that R contains a hyphen character and that S does not.
38Suppose that the current font is R. Suppose that \(ch is in a word
39and has a non-zero hyphen-type. Then we ought to be able to hyphenate,
40but we won't be able to because we will look for the hyphen only in
41font S and not in font R.
42
43Perhaps the current input level should be accessible in a number register.
44
45Should \w deal with a newline like \X?
46
47Have another look at uses of token::delimiter.  Perhaps we need to
48distinguish the case where we want to see if a token could start a
49number, from the case where we want to see if it could occur somewhere
50in a number expression.
51
52Provide a facility like copy thru in pic.
53
54Fancier implementation of font families which doesn't group fonts into
55families purely on the basis of their names.
56
57In the DESC file make the number of fonts optional if they are all on
58one line.
59
60Number register to give the diversion level.
61
62Time various alternative implementations of scale (both in font.c and
63number.c). On a sparc it's faster to always do it in floating point.
64
65Devise a more compact representation for the hyphenation patterns trie.
66
67Have a per-environment parameter to increase letter-spacing.
68
69Number register to return character height.
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71Number register to return character slant.
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73Request to set character height.
74
75Request to set character slant.
76
77Provide some way to upcase or downcase strings.
78
79Support non-uniformly scalable fonts. Perhaps associate a suffix with
80a particular range of sizes.  eg
81  sizesuffix .display 14-512
82Then is you ask for R at pointsize 16, groff will first look for
83R.display and then R.  Probably necessary to be able to specify a
84separate unitwidth for each sizesuffix (eg. for X).
85
86Variant of `.it' for which a line interrupted with \c counts as one
87input line.
88
89Make it possible to suppress hyphenation on a word-by-word basis.
90(Perhaps store hyphenation flags in tfont.)
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92Possibly allow multiple simultaneous input line traps.
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94Unpaddable, breakable space escape sequence.
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96Support hanging punctuation.
97
98In justified text, if the last line of a paragraph is only a little
99bit short it might be desirable to justify the line.  Allow the user
100control over this.
101
102The pm request could print where the macro was defined.  Also could
103optionally print the contents of a macro.
104
105Provide some way to round numbers to multiples of the current
106horizontal or vertical resolution.
107
108Better string-processing support (search).
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110Generalized ligatures.
111
112Provide some way for a macro to tell whether it was called with `'' or
113`.'.  This would be useful for implementing a tracing macro package.
114
115Request to remove an environment. (Maintain a count of the references
116to the environment from the environment table, environment dictionary
117or environment stack.)
118
119Perhaps in the nr request a leading `-' should only be recognized as a
120decrement when it's at the same input level as the request.
121
122Don't ever change a charinfo.  Create new variants instead and chain
123them together.
124
125Unix troff appears to read the first character of a request name in
126copy mode.  Should we do the same?
127
128Number register giving name of end macro.
129
130More thorough range checking.
131
132Provide syntax for octal and hexadecimal numeric constants.  Perhaps
133o#100 and x#7f as per Scheme.  Or perhaps PostScript 16#7f.  Ambiguity
134between whether `c' is treated as digit or scaling indicator.
135