Merge 66317dc into 8ff8c62

packages/math/init.lua

@@ -16,6 +16,7 @@ function package:_init ()
       return value * SILE.settings:get("math.font.size") / 18
     end
   })
+  self:loadPackage("counters")
 end
 
 function package.declareSettings (_)
@@ -62,23 +63,30 @@ end
 function package:registerCommands ()
 
   self:registerCommand("mathml", function (options, content)
-    local mode = (options and options.mode) and options.mode or 'text'
     local mbox
     xpcall(function()
       mbox = self:ConvertMathML(content)
     end, function(err) print(err); print(debug.traceback()) end)
-    self:handleMath(mbox, mode)
+    self:handleMath(mbox, options)
   end)
 
   self:registerCommand("math", function (options, content)
-    local mode = (options and options.mode) and options.mode or "text"
     local mbox
     xpcall(function()
       mbox = self:ConvertMathML(self:compileToMathML({}, self:convertTexlike(content)))
     end, function(err) print(err); print(debug.traceback()) end)
-    self:handleMath(mbox, mode)
+    self:handleMath(mbox, options)
   end)
 
+  self:registerCommand("math:numberingstyle", function (options, _)
+    SILE.typesetter:typeset("(")
+    if options.counter then
+      SILE.call("show-counter", { id = options.counter })
+    elseif options.number then
+      SILE.typesetter:typeset(options.number)
+    end
+    SILE.typesetter:typeset(")")
+  end)
 end
 
 package.documentation = [[
@@ -344,6 +352,19 @@ Finally, here is a little secret. This notation:
 
 \noindent In other words, the notation using \code{&} and \code{\\\\} is only a syntactic sugar for a two-dimensional array constructed with braces.
 
+\paragraph{Numbered equations}
+Equations can be numbered in display mode.
+
+When \autodoc:parameter{numbered=true}, equations are numbered using a default “equation” counter:
+\math[mode=display, numbered=true]{e^{i\pi} = -1}
+
+A different counter can be set by using the option \autodoc:parameter{counter=<id>}, and this setting will also enable numbering.
+
+It is also possible to impose direct numbering using the \autodoc:parameter{number=<value>} option.
+
+The default numbering format is \autodoc:example{(n)}, but this style may be overridden by defining a custom \autodoc:command{\math:numberingstyle} command.
+The \code{counter} or the direct value \code{number} is passed as a parameter to this hook, as well as any other options.
+
 \paragraph{Missing features}
 This package still lacks support for some mathematical constructs, but hopefully we’ll get there.
 Among unsupported constructs are: decorating symbols with so-called accents, such as arrows or hats, “over” or “under” braces, and line breaking inside a formula.

packages/math/typesetter.lua

@@ -126,7 +126,11 @@ function ConvertMathML (_, content)
   end
 end
 
-local function handleMath (_, mbox, mode)
+local function handleMath (_, mbox, options)
+  local mode = options and options.mode or 'text'
+  local counter = SU.boolean(options.numbered, false) and "equation"
+  counter = options.counter or counter  -- overrides the default "equation" counter
+
   if mode == 'display' then
     mbox.mode = b.mathMode.display
   elseif mode == 'text' then
@@ -144,10 +148,28 @@ local function handleMath (_, mbox, mode)
   if mode == "display" then
     SILE.typesetter:endline()
     SILE.typesetter:pushExplicitVglue(SILE.settings:get("math.displayskip"))
-    SILE.call("center", {}, function()
+    SILE.settings:temporarily(function ()
+      -- Center the equation in the space available up to the counter (if any),
+      -- respecting the fixed part of the left and right skips.
+      local lskip = SILE.settings:get("document.lskip") or SILE.types.node.glue()
+      local rskip = SILE.settings:get("document.rskip") or SILE.types.node.glue()
+      SILE.settings:set("document.parindent", SILE.types.node.glue())
+      SILE.settings:set("current.parindent", SILE.types.node.glue())
+      SILE.settings:set("document.lskip", SILE.types.node.hfillglue(lskip.width.length))
+      SILE.settings:set("document.rskip", SILE.types.node.glue(rskip.width.length))
+      SILE.settings:set("typesetter.parfillskip", SILE.types.node.glue())
+      SILE.settings:set("document.spaceskip", SILE.types.length("1spc", 0, 0))
       SILE.typesetter:pushHorizontal(mbox)
+      SILE.typesetter:pushExplicitGlue(SILE.nodefactory.hfillglue())
+      if counter then
+        options.counter = counter
+        SILE.call("increment-counter", { id = counter })
+        SILE.call("math:numberingstyle", options)
+      elseif options.number then
+        SILE.call("math:numberingstyle", options)
+      end
+      SILE.typesetter:endline()
     end)
-    SILE.typesetter:endline()
     SILE.typesetter:pushExplicitVglue(SILE.settings:get("math.displayskip"))
   else
     SILE.typesetter:pushHorizontal(mbox)

tests/feat-math-display-numbered.sil

@@ -0,0 +1,45 @@
+\begin[papersize=a6]{document}
+\nofolios
+\neverindent
+\use[module=packages.lorem]
+\use[module=packages.math]
+\font[size=11pt]
+% Test numbered display math for all options
+% and in all alignments
+
+Begin justified
+\math[mode=display, numbered=true]{e^{i\pi} = -1}
+End justified.
+
+\begin{center}
+Begin centered
+\math[mode=display, numbered=true]{e^{i\pi} = -1}
+End centered
+\end{center}
+
+\begin{raggedright}
+Begin left-aligned
+\math[mode=display, numbered=true]{e^{i\pi} = -1}
+End left-aligned.
+\end{raggedright}
+
+\begin{raggedleft}
+Begin right-aligned
+\math[mode=display, numbered=true]{e^{i\pi} = -1}
+End right-aligned
+\end{raggedleft}
+
+Custom counter
+\set-counter[id=my-counter, display=alpha]
+\begin[mode=display, counter=my-counter]{math}
+    \{
+    \table[columnalign=right center left]{
+        u_0 &=& C \\
+        u_n &=& r \times u_{n−1}, \forall n ⩾ 1 \\
+    }
+\end{math}
+
+Direct numbering
+\math[mode=display, number=5C]{1 = -e^{i\pi}}
+
+\end{document}

tests/feat-math-display-unnumbered.sil

@@ -0,0 +1,35 @@
+\begin[papersize=a6]{document}
+\nofolios
+\neverindent
+\use[module=packages.lorem]
+\use[module=packages.math]
+\font[size=11pt]
+% Test default (unnumbered) display math
+% within a blockquote (to check it honors margin skips)
+% and in all alignments
+
+\begin{blockquote}
+Begin justified
+\math[mode=display]{e^{i\pi} = -1}
+End justified.
+
+\begin{center}
+Begin centered
+\math[mode=display]{e^{i\pi} = -1}
+End centered
+\end{center}
+
+\begin{raggedright}
+Begin left-aligned
+\math[mode=display]{e^{i\pi} = -1}
+End left-aligned.
+\end{raggedright}
+
+\begin{raggedleft}
+Begin right-aligned
+\math[mode=display]{e^{i\pi} = -1}
+End right-aligned
+\end{raggedleft}
+\end{blockquote}
+
+\end{document}