math-frc.lua /size: 2911 b    last modification: 2020-07-01 14:35
1if not modules then modules = { } end modules ['math-frc'] = {
2    version   = 1.001,
3    comment   = "companion to math-frc.mkiv",
4    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
5    copyright = "PRAGMA ADE / ConTeXt Development Team",
6    license   = "see context related readme files"
7}
8
9local utfchar   = utf.char
10
11local context   = context
12local variables = interfaces.variables
13
14local v_no      = variables.no
15local v_yes     = variables.yes
16local v_hidden  = variables.hidden
17
18local resolved  = {
19    [0x007B] = "\\{",
20    [0x007D] = "\\}",
21}
22
23table.setmetatableindex(resolved, function(t,k)
24    local v = utfchar(k)
25    t[k] = v
26    return v
27end)
28
29local ctx_normalatop = context.normalatop
30local ctx_normalover = context.normalover
31
32local function mathfraction(how,left,right,width)
33    if how == v_no then
34        if left == 0x002E and right == 0x002E then
35            ctx_normalatop()
36        else
37            context("\\atopwithdelims%s%s",resolved[left],resolved[right])
38        end
39    elseif how == v_yes or how == v_hidden then
40        local norule = how == v_hidden and LUATEXFUNCTIONALITY > 7361 and " norule " or ""
41        if left == 0x002E and right == 0x002E then
42            context("\\normalabove%s%s%ssp",norule,width)
43        else
44            context("\\abovewithdelims%s%s%s%s%ssp",norule,resolved[left],resolved[right],width)
45        end
46    else -- v_auto
47        if left == 0x002E and right == 0x002E then
48            ctx_normalover()
49        else
50            context("\\overwithdelims%s%s",resolved[left],resolved[right])
51        end
52    end
53end
54
55interfaces.implement {
56    name      = "mathfraction",
57    actions   = mathfraction,
58    arguments = { "string", "number", "number", "dimen" }
59}
60
61-- experimental code in lmtx
62
63if CONTEXTLMTXMODE > 0 then
64
65    local ctx_Uatop = context.Uatop
66    local ctx_Uover = context.Uover
67
68    local function umathfraction(how,left,right,width)
69        if how == v_no then
70            if left == 0x002E and right == 0x002E then
71                ctx_Uatop()
72            else
73                context("\\Uatopwithdelims%s%s",resolved[left],resolved[right])
74            end
75        elseif how == v_yes or how == v_hidden then
76            local norule = how == v_hidden and " norule " or ""
77            if left == 0x002E and right == 0x002E then
78                context("\\Uabove%s%ssp",norule,width)
79            else
80                context("\\Uabovewithdelims%s%s%s%ssp",norule,resolved[left],resolved[right],width)
81            end
82        else -- v_auto
83            if left == 0x002E and right == 0x002E then
84                ctx_Uover()
85            else
86                context("\\Uoverwithdelims%s%s",resolved[left],resolved[right])
87            end
88        end
89    end
90
91    interfaces.implement {
92        name      = "umathfraction",
93        actions   = umathfraction,
94        arguments = { "string", "number", "number", "dimen" }
95    }
96
97end
98