diff options
| -rw-r--r-- | data/pandoc.lua | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/data/pandoc.lua b/data/pandoc.lua index 370c6a944..e69f8ac9c 100644 --- a/data/pandoc.lua +++ b/data/pandoc.lua @@ -73,6 +73,39 @@ local function create_accessor_functions (fn_template, accessors) return res end +--- Get list of top-level fields from field descriptor table. +-- E.g.: `top_level_fields{'foo', {bar='baz'}, {'qux', 'quux'}}` +-- gives {'foo, 'bar', 'qux', 'quux'} +-- @local +local function top_level_fields (fields) + local result = List:new{} + for _, v in ipairs(fields) do + if type(v) == 'string' then + table.insert(result, v) + elseif type(v) == 'table' and #v == 0 and next(v) then + table.insert(result, (next(v))) + else + result:extend(top_level_fields(v)) + end + end + return result +end + +--- Creates a function which behaves like next, but respects field names. +-- @local +local function make_next_function (fields) + local field_indices = {} + for i, f in ipairs(fields) do + field_indices[f] = i + end + + return function (t, field) + local raw_idx = field == nil and 0 or field_indices[field] + local next_field = fields[raw_idx + 1] + return next_field, t[next_field] + end +end + --- Create a new table which allows to access numerical indices via accessor -- functions. -- @local @@ -102,6 +135,15 @@ local function create_accessor_behavior (tag, accessors) rawset(t, k, v) end end + behavior.__pairs = function (t) + if accessors == nil then + return next, t + end + local iterable_fields = type(accessors) == 'string' + and {accessors} + or top_level_fields(accessors) + return make_next_function(iterable_fields), t + end return behavior end @@ -842,6 +884,14 @@ M.Attr.behavior.__newindex = function(t, k, v) rawset(t, k, v) end end +M.Attr.behavior.__pairs = function(t) + local field_names = M.Attr.behavior._field_names + local fields = {} + for name, i in pairs(field_names) do + fields[i] = name + end + return make_next_function(fields), t, nil +end -- Citation M.Citation = AstElement:make_subtype'Citation' @@ -892,6 +942,14 @@ M.ListAttributes.behavior.__newindex = function (t, k, v) rawset(t, k, v) end end +M.ListAttributes.behavior.__pairs = function(t) + local field_names = M.ListAttributes.behavior._field_names + local fields = {} + for name, i in pairs(field_names) do + fields[i] = name + end + return make_next_function(fields), t, nil +end ------------------------------------------------------------------------ |