better fuzzy matching + vfs type flag in Files

sys/modules/opus/fuzzy.lua

@@ -1,21 +1,56 @@
--- Based on Squid's fuzzy search
--- https://github.com/SquidDev-CC/artist/blob/vnext/artist/lib/match.lua
---
--- not very fuzzy anymore
+local find  = string.find
+local floor = math.floor
+local min   = math.min
+local max   = math.max
+local sub   = string.sub
 
-local SCORE_WEIGHT               = 1000
-local LEADING_LETTER_PENALTY     = -30
-local LEADING_LETTER_PENALTY_MAX = -90
-
-local _find = string.find
-local _max  = math.max
-
-return function(str, pattern)
-	local start = _find(str, pattern, 1, true)
-	if start then
-		-- All letters before the current one are considered leading, so add them to our penalty
-		return SCORE_WEIGHT
-			+ _max(LEADING_LETTER_PENALTY * (start - 1), LEADING_LETTER_PENALTY_MAX)
-			- (#str - #pattern)
+-- https://rosettacode.org/wiki/Jaro_distance (ported to lua)
+return function(s1, s2)
+	local l1, l2 = #s1, #s2;
+    if l1 == 0 then
+		return l2 == 0 and 1.0 or 0.0
 	end
+
+	local match_distance = max(floor(max(l1, l2) / 2) - 1, 0)
+    local s1_matches = { }
+    local s2_matches = { }
+    local matches = 0
+
+	for i = 1, l1 do
+        local _end = min(i + match_distance + 1, l2)
+		for k = max(1, i - match_distance), _end do
+            if not s2_matches[k] and sub(s1, i, i) == sub(s2, k, k) then
+                s1_matches[i] = true
+                s2_matches[k] = true
+                matches = matches + 1
+                break
+			end
+		end
+	end
+    if matches == 0 then
+		return 0.0
+	end
+
+    local t = 0.0
+    local k = 1
+	for i = 1, l1 do
+        if s1_matches[i] then
+			while not s2_matches[k] do
+				k = k + 1
+			end
+			if sub(s1, i, i) ~= sub(s2, k, k) then
+				t = t + 0.5
+			end
+            k = k + 1
+		end
+	end
+
+	-- provide a major boost for exact matches
+	local b = 0.0
+	if find(s1, s2, 1, true) then
+		b = b + .5
+	end
+
+    local m = matches
+    return (m / l1 + m / l2 + (m - t) / m) / 3.0 + b
 end