Lua module: provide multi-param Inline constructors

Instead of taking only a single argument containing the pre-packed
element contents, `Inline` constructors now take the same arguments as
the respective filter and `Custom` writer function

data/pandoc.lua

@@ -26,7 +26,10 @@ function M.Attributes(id, classes, key_values)
   return {id, classes, key_values}
 end
 
+------------------------------------------------------------------------
+--- Document AST elements
 local Element = {}
+
 --- Create a new element subtype
 function Element:make_subtype(o)
   o = o or {}
@@ -34,6 +37,7 @@ function Element:make_subtype(o)
   self.__index = self
   return o
 end
+
 --- Create a new element given its tag and arguments
 function Element:new(tag, ...)
   local element = { t = tag }
@@ -51,6 +55,35 @@ function Element:new(tag, ...)
   return element
 end
 
+--- Create a new constructor
+-- @param tag Tag used to identify the constructor
+-- @param fn Function to be called when constructing a new element
+-- @return function that constructs a new element
+function Element:create_constructor(tag, fn)
+  local constr = self:make_subtype({tag = tag})
+  function constr:new(...)
+    local obj = fn(...)
+    setmetatable(obj, self)
+    self.__index = function(t, k)
+      if k == "c" then
+        return t["content"]
+      elseif k == "t" then
+        return getmetatable(t)["tag"]
+      else
+        return getmetatable(t)[k]
+      end
+    end
+    return obj
+  end
+  return constr
+end
+
+function Element.__call(t, ...)
+  return t:new(...)
+end
+
+------------------------------------------------------------------------
+-- Document
 local function Doc(blocks, meta)
   return {
     ["blocks"] = blocks,
@@ -58,10 +91,132 @@ local function Doc(blocks, meta)
     ["pandoc-api-version"] = {1,17,0,5},
   }
 end
-
 local Inline = Element:make_subtype{}
+function Inline.__call(t, ...)
+  return t:new(...)
+end
+
 local Block = Element:make_subtype{}
 
+------------------------------------------------------------------------
+-- Inline element constructors
+-- @section
+
+--- Create a Cite inline element
+-- @function Inline.Cite
+Inline.Cite = Inline:create_constructor(
+  "Cite",
+  function(lst, cs) return {c = {cs, lst}} end
+)
+--- Create a Code inline element
+-- @function Inline.Code
+Inline.Code = Inline:create_constructor(
+  "Code",
+  function(code, attr) return {c = {attr, code}} end
+)
+--- Create a Emph inline element
+-- @function Inline.Emph
+Inline.Emph = Inline:create_constructor(
+  "Emph",
+  function(xs) return {c = xs} end
+)
+--- Create a Image inline element
+-- @function Inline.Image
+Inline.Image = Inline:create_constructor(
+  "Image",
+  function(capt, src, tit, attr) return {c = {attr, capt, {src, tit}}} end
+)
+--- Create a LineBreak inline element
+-- @function Inline.LineBreak
+Inline.LineBreak = Inline:create_constructor(
+  "LineBreak",
+  function() return {} end
+)
+--- Create a Link inline element
+-- @function Inline.Link
+Inline.Link = Inline:create_constructor(
+  "Link",
+  function(txt, src, tit, attr) return {c = {attr, txt, {src, tit}}} end
+)
+--- Create a Math inline element
+-- @function Inline.Math
+Inline.Math = Inline:create_constructor(
+  "Math",
+  function(m, str) return {c = {m, str}} end
+)
+--- Create a Note inline element
+-- @function Inline.Note
+Inline.Note = Inline:create_constructor(
+  "Note",
+  function(contents) return {c = contents} end
+)
+--- Create a Quoted inline element
+-- @function Inline.Quoted
+Inline.Quoted = Inline:create_constructor(
+  "Quoted",
+  function(qt, lst) return {c = {qt, lst}} end
+)
+--- Create a RawInline inline element
+-- @function Inline.RawInline
+Inline.RawInline = Inline:create_constructor(
+  "RawInline",
+  function(f, xs) return {c = {f, xs}} end
+)
+--- Create a SmallCaps inline element
+-- @function Inline.SmallCaps
+Inline.SmallCaps = Inline:create_constructor(
+  "SmallCaps",
+  function(xs) return {c = xs} end
+)
+--- Create a SoftBreak inline element
+-- @function Inline.SoftBreak
+Inline.SoftBreak = Inline:create_constructor(
+  "SoftBreak",
+  function() return {} end
+)
+--- Create a Space inline element
+-- @function Inline.Space
+Inline.Space = Inline:create_constructor(
+  "Space",
+  function() return {} end
+)
+--- Create a Span inline element
+-- @function Inline.Span
+Inline.Span = Inline:create_constructor(
+  "Span",
+  function(ls, attr) return {c = {attr, xs}} end
+)
+--- Create a Str inline element
+-- @function Inline.Str
+Inline.Str = Inline:create_constructor(
+  "Str",
+  function(str) return {c = str} end
+)
+--- Create a Strikeout inline element
+-- @function Inline.Strikeout
+Inline.Strikeout = Inline:create_constructor(
+  "Strikeout",
+  function(xs) return {c = xs} end
+)
+--- Create a Strong inline element
+-- @function Inline.Strong
+Inline.Strong = Inline:create_constructor(
+  "Strong",
+  function(xs) return {c = xs} end
+)
+--- Create a Subscript inline element
+-- @function Inline.Subscript
+Inline.Subscript = Inline:create_constructor(
+  "Subscript",
+  function(xs) return {c = xs} end
+)
+--- Create a Superscript inline element
+-- @function Inline.Superscript
+Inline.Superscript = Inline:create_constructor(
+  "Superscript",
+  function(xs) return {c = xs} end
+)
+
 M.block_types = {
   "BlockQuote",
   "BulletList",
@@ -102,6 +257,7 @@ M.inline_types = {
   "Superscript"
 }
 
+
 for _, block_type in pairs(M.block_types) do
   M[block_type] = function(...)
     return Block:new(block_type, ...)
@@ -109,9 +265,7 @@ for _, block_type in pairs(M.block_types) do
 end
 
 for _, inline_type in pairs(M.inline_types) do
-  M[inline_type] = function(...)
+  M[inline_type] = Inline[inline_type]
-    return Inline:new(inline_type, ...)
-  end
 end
 
 --- Arrays to provide fast lookup of element types
@@ -136,5 +290,7 @@ function M.global_filter()
 end
 
 M["Doc"] = Doc
+M["Inline"] = Inline
+M["Block"] = Block
 
 return M