Update prepare-credit.lua

Author: cthoyt

data/filters/prepare-credit.lua

@@ -73,16 +73,22 @@ local roles = {
     }
 }
 
+-- An enumeration of the JATS-recommended degrees of contribution
 degrees = pandoc.List {
     "Lead",
     "Supporting",
     "Equal"
 }
 
-function invalidRole(str)
+-- Check if the given string is one of the 14 valid
+-- CRediT identifiers by looking at the `roles` dict
+-- defined above
+function invalidCreditID(str)
     return roles[str] == nil
 end
 
+-- Check if the degree contribution is valid based on the JATS recommendation,
+-- see https://jats.taylorandfrancis.com/jats-guide/topics/author-contributions-credit/#degree-of-contribution
 function invalidDegree(str)
     return not degrees:includes(str)
 end
@@ -105,6 +111,9 @@ function capitalize_first_letter(str)
     return str:sub(1, 1):upper() .. str:sub(2)
 end
 
+-- If the data is just a string corresponding to a
+-- CRediT identifier, upgrade it to a dictionary,
+-- otherwise return it as is
 function clean_role_dict(d)
     if d.credit then
         return d
@@ -121,7 +130,7 @@ local function prepare_credit (meta)
             for _, roleDict in ipairs(author.roles) do
                 roleDict = clean_role_dict(roleDict)
                 credit_id = pandoc.utils.stringify(roleDict.credit)
-                if invalidRole(credit_id) then
+                if invalidCreditID(credit_id) then
                     print("invalid credit ID for author " .. author.name .. ": " .. credit_id)
                 elseif roleDict.degree then
                     degree = capitalize_first_letter(pandoc.utils.stringify(roleDict.degree))