2016-01-12 16:26:00

1 files changed, 57 insertions, 0 deletions

diff --git a/tex/context/base/mkiv/math-frc.lua b/tex/context/base/mkiv/math-frc.lua
new file mode 100644
index 000000000..639edc94b
--- /dev/null
+++ b/tex/context/base/mkiv/math-frc.lua
@@ -0,0 +1,57 @@
+if not modules then modules = { } end modules ['math-frc'] = {
+    version   = 1.001,
+    comment   = "companion to math-frc.mkiv",
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files"
+}
+
+local utfchar = utf.char
+
+local context = context
+local variables = interfaces.variables
+
+local v_no  = variables.no
+local v_yes = variables.yes
+
+local resolved = {
+    [0x007B] = "\\{",
+    [0x007D] = "\\}",
+}
+
+table.setmetatableindex(resolved, function(t,k)
+    local v = utfchar(k)
+    t[k] = v
+    return v
+end)
+
+local ctx_normalatop = context.normalatop
+local ctx_normalover = context.normalover
+
+local function mathfraction(how,left,right,width) -- of course we could use the scanners directly here which
+    if how == v_no then                           -- is faster but also less abstract ... maybe some day
+        if left == 0x002E and right == 0x002E then
+            ctx_normalatop()
+        else
+            context("\\atopwithdelims%s%s",resolved[left],resolved[right])
+        end
+    elseif how == v_yes then
+        if left == 0x002E and right == 0x002E then
+            context("\\normalabove%ssp",width)
+        else
+            context("\\abovewithdelims%s%s%ssp",resolved[left],resolved[right],width)
+        end
+    else -- v_auto
+        if left == 0x002E and right == 0x002E then
+            ctx_normalover()
+        else
+            context("\\overwithdelims%s%s",resolved[left],resolved[right])
+        end
+    end
+end
+
+interfaces.implement {
+    name      = "mathfraction",
+    actions   = mathfraction,
+    arguments = { "string", "number", "number", "dimen" }
+}