Improve search results order in Seal filesearch plugin

Spotlight results naturally put first the items that
were recently accessed.
However it doesn't put first the item that really
contain the word as it (not as a sub-part of the word)
whereas it is often the ones you want first typically.

We emulate that behaviour by re-ordering the results
to boost the item that contains whole words.

Author: yannrouillard

Source/Seal.spoon/seal_filesearch.lua

@@ -55,6 +55,29 @@ EMPTY_QUERY = ".*"
 
 local log = hs.logger.new('seal_filesearch', 'info')
 
+---
+-- Generic helper functions
+---
+
+local imapWithIndex = function(t, mapFn)
+    local mappedTable = {}
+    for i, v in ipairs(t) do
+        mappedTable[#mappedTable + 1] = mapFn(v, i)
+    end
+    return mappedTable
+end
+
+local containsWholeWord = function(s, word)
+    local pattern = "%f[%w]" .. string.lower(word) .. "%f[%W]"
+    return string.find(string.lower(s), pattern)
+end
+
+local containsCamelCaseWholeWord = function(s, word)
+    local camelCaseWord = word:sub(1, 1):upper() .. word:sub(2):lower()
+    local pattern = "%f[%u]" .. camelCaseWord .. "(%f[%u%z])"
+    return string.find(s, pattern)
+end
+
 ---
 -- Spotlight Helper class
 ---
@@ -151,7 +174,7 @@ end
 -- Private functions
 ---
 
-local convertSpotlightResultToQueryResult = function(item)
+local convertSpotlightResultToQueryResult = function(item, index)
     local icon = hs.image.iconForFile(item.kMDItemPath)
     local bundleID = item.kMDItemCFBundleIdentifier
     if (not icon) and (bundleID) then
@@ -164,13 +187,43 @@ local convertSpotlightResultToQueryResult = function(item)
         uuid = obj.__name .. "__" .. (bundleID or item.kMDItemDisplayName),
         plugin = obj.__name,
         type = "open",
-        image = icon
+        image = icon,
+        index = index
     }
 end
 
+-- This function returns a sort function suitable for table.sort
+-- that will boost the search results that:
+--   * contains the whole word (not part of another word)
+--   * contains the word in CamelCase
+local buildBoostResultsSortForQuery = function(query)
+    local queryWords = hs.fnutils.split(query, "%s+")
+    local scoreItem = function(item)
+        local score = 0
+        for _, word in ipairs(queryWords) do
+            if containsWholeWord(item.text, word) or containsCamelCaseWholeWord(item.text, word) then
+                score = score + 1
+            end
+        end
+        return score
+    end
+
+    return function(itemA, itemB)
+        local scoreA = scoreItem(itemA)
+        local scoreB = scoreItem(itemB)
+        if scoreA ~= scoreB then
+            return scoreA > scoreB
+        else
+            -- we just preserve the existing order otherwise
+            return itemA.index < itemB.index
+        end
+    end
+end
+
 local handleFileSearchResults = function(query, searchResults)
     if query == obj.currentQuery then
-        obj.currentQueryResults = hs.fnutils.map(searchResults, convertSpotlightResultToQueryResult)
+        obj.currentQueryResults = imapWithIndex(searchResults, convertSpotlightResultToQueryResult)
+        table.sort(obj.currentQueryResults, buildBoostResultsSortForQuery(query))
         obj.seal.chooser:refreshChoicesCallback()
     end
 end