init

scholarly-metadata.lua

@@ -0,0 +1,199 @@
+--[[
+ScholarlyMeta – normalize author/affiliation meta variables
+
+Copyright (c) 2017-2021 Albert Krewinkel, Robert Winkler
+
+Permission to use, copy, modify, and/or distribute this software for any purpose
+with or without fee is hereby granted, provided that the above copyright notice
+and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
+OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
+THIS SOFTWARE.
+]]
+local List = require 'pandoc.List'
+
+--- Returns the type of a metadata value.
+--
+-- @param v a metadata value
+-- @treturn string one of `Blocks`, `Inlines`, `List`, `Map`, `string`, `boolean`
+local function metatype (v)
+  if PANDOC_VERSION <= '2.16.2' then
+    local metatag = type(v) == 'table' and v.t and v.t:gsub('^Meta', '')
+    return metatag and metatag ~= 'Map' and metatag or type(v)
+  end
+  return pandoc.utils.type(v)
+end
+
+local type = pandoc.utils.type or metatype
+
+
+-- Split a string at commas.
+local function comma_separated_values(str)
+  local acc = List:new{}
+  for substr in str:gmatch('([^,]*)') do
+    acc[#acc + 1] = substr:gsub('^%s*', ''):gsub('%s*$', '') -- trim
+  end
+  return acc
+end
+
+--- Ensure the return value is a list.
+local function ensure_list (val)
+  if type(val) == 'List' then
+    return val
+  elseif type(val) == 'Inlines' then
+    -- check if this is really a comma-separated list
+    local csv = comma_separated_values(pandoc.utils.stringify(val))
+    if #csv >= 2 then
+      return csv
+    end
+    return List:new{val}
+  elseif type(val) == 'table' and #val > 0 then
+    return List:new(val)
+  else
+    -- Anything else, use as a singleton (or empty list if val == nil).
+    return List:new{val}
+  end
+end
+
+--- Returns a function which checks whether an object has the given ID.
+local function has_id (id)
+  return function(x) return x.id == id end
+end
+
+--- Copy all key-value pairs of the first table into the second iff there is no
+-- such key yet in the second table.
+-- @returns the second argument
+function add_missing_entries(a, b)
+  for k, v in pairs(a) do
+    b[k] = b[k] or v
+  end
+  return b
+end
+
+--- Create an object with a name. The name is either taken directly from the
+-- `name` field, or from the *only* field name (i.e., key) if the object is a
+-- dictionary with just one entry. If neither exists, the name is left unset
+-- (`nil`).
+function to_named_object (obj)
+  local named = {}
+  if type(obj) == 'Inlines' then
+    -- Treat inlines as the name
+    named.name = obj
+    named.id = pandoc.utils.stringify(obj)
+  elseif type(obj) ~= 'table' then
+    -- if the object isn't a table, just use its value as a name.
+    named.name = pandoc.MetaInlines{pandoc.Str(tostring(obj))}
+    named.id = tostring(obj)
+  elseif obj.name ~= nil then
+    -- object has name attribute → just create a copy of the object
+    add_missing_entries(obj, named)
+    named.id = pandoc.utils.stringify(named.id or named.name)
+  elseif next(obj) and next(obj, next(obj)) == nil then
+    -- Single-entry table. The entry's key is taken as the name, the value
+    -- contains the attributes.
+    key, attribs = next(obj)
+    if type(attribs) == 'string' or type(attribs) == 'Inlines' then
+      named.name = attribs
+    else
+      add_missing_entries(attribs, named)
+      named.name = named.name or pandoc.MetaInlines{pandoc.Str(tostring(key))}
+    end
+    named.id = named.id and pandoc.utils.stringify(named.id) or key
+  else
+    -- this is not a named object adhering to the usual conventions.
+    error('not a named object: ' .. tostring(obj))
+  end
+  return named
+end
+
+--- Resolve institute placeholders to full named objects
+local function resolve_institutes (institute, known_institutes)
+  local unresolved_institutes
+  if institute == nil then
+    unresolved_institutes = {}
+  elseif type(institute) == "string" or type(institute) == "number" then
+    unresolved_institutes = {institute}
+  else
+    unresolved_institutes = institute
+  end
+
+  local result = List:new{}
+  for i, inst in ipairs(unresolved_institutes) do
+    result[i] =
+      known_institutes[tonumber(inst)] or
+      known_institutes:find_if(has_id(pandoc.utils.stringify(inst))) or
+      to_named_object(inst)
+  end
+  return result
+end
+
+--- Insert a named object into a list; if an object of the same name exists
+-- already, add all properties only present in the new object to the existing
+-- item.
+function merge_on_id (list, namedObj)
+  local elem, idx = list:find_if(has_id(namedObj.id))
+  local res = elem and add_missing_entries(namedObj, elem) or namedObj
+  local obj_idx = idx or (#list + 1)
+  -- return res, obj_idx
+  list[obj_idx] = res
+  return res, #list
+end
+
+--- Flatten a list of lists.
+local function flatten (lists)
+  local result = List:new{}
+  for _, lst in ipairs(lists) do
+    result:extend(lst)
+  end
+  return result
+end
+
+--- Canonicalize authors and institutes
+local function canonicalize(raw_author, raw_institute)
+  local institutes = ensure_list(raw_institute):map(to_named_object)
+  local authors = ensure_list(raw_author):map(to_named_object)
+
+  for _, author in ipairs(authors) do
+    author.institute = resolve_institutes(
+      ensure_list(author.institute),
+      institutes
+    )
+  end
+
+  -- Merge institutes defined in author objects with those defined in the
+  -- top-level list.
+  local author_insts = flatten(authors:map(function(x) return x.institute end))
+  for _, inst in ipairs(author_insts) do
+    merge_on_id(institutes, inst)
+  end
+
+  -- Add list indices to institutes for numbering and reference purposes
+  for idx, inst in ipairs(institutes) do
+    inst.index = pandoc.MetaInlines{pandoc.Str(tostring(idx))}
+  end
+
+  -- replace institutes with their indices
+  local to_index = function (inst)
+    return tostring(select(2, institutes:find_if(has_id(inst.id))))
+  end
+  for _, author in ipairs(authors) do
+    author.institute = pandoc.MetaList(author.institute:map(to_index))
+  end
+
+  return authors, institutes
+end
+
+
+return {
+  {
+    Meta = function(meta)
+      meta.author, meta.institute = canonicalize(meta.author, meta.institute)
+      return meta
+    end
+  }
+}