solve #30

src/edit.jl

@@ -124,24 +124,26 @@ function (dist::DamerauLevenshtein)(s1, s2, max_dist::Union{Integer, Nothing} =
     v = collect(1:(len2-k))
     w = similar(v)
     if max_dist !== nothing
-        i2_start = k + 1
-        i2_end = max_dist
+        i2_start = 1
+        i2_end = max_dist + 1
     end
     prevch1, prevch2 = first(s1), first(s2)
     current = 0
     for (i1, ch1) in enumerate(s1)
         i1 <= k && continue
-        left = current = i1 - k - 1
+        left = i1 - k - 1
+        current = left + 1
         nextTransCost = 0
         if max_dist !== nothing
-            i2_start += (i1 > 1 + max_dist - (len2 - len1)) ? 1 : 0
-            i2_end += (i2_end < len2) ? 1 : 0
+            i2_start += (i1 - k - 1 > max_dist - (len2 - len1)) ? 1 : 0
+            i2_end += (i2_end <= len2) ? 1 : 0
         end
         for (i2, ch2) in enumerate(s2)
-            i2 <= k && continue
-            # no need to look beyond window of lower right diagonal - maxDistance cells 
-            #lower right diag is i1 - (len2 - len1)) and the upper left diagonal + max_dist cells (upper left is i1)
-            if (max_dist !== nothing) && ((i2 < i2_start) | (i2 > i2_end))
+            if i2 <= k 
+                prevch2 = ch2
+            elseif (max_dist !== nothing) && ((i2 - k < i2_start) | (i2 - k >= i2_end))
+                # no need to look beyond window of lower right diagonal - maxDistance cells 
+                #lower right diag is i1 - (len2 - len1)) and the upper left diagonal + max_dist cells (upper left is i1)
                 prevch2 = ch2
             else
                 above, current, left = current, left, v[i2 - k]
@@ -150,7 +152,7 @@ function (dist::DamerauLevenshtein)(s1, s2, max_dist::Union{Integer, Nothing} =
                 if ch1 != ch2
                     current = min(left, current, above) + 1
                     # never happens at i2 = k + 1 because then the two previous characters were equal
-                    if (i1 > 1 + k) & (i2 > 1 + k) && (ch1 == prevch2) && (prevch1 == ch2)
+                    if (i1 - k > 1) & (i2 - k > 1) && (ch1 == prevch2) && (prevch1 == ch2)
                         thisTransCost += 1
                         current = min(current, thisTransCost)
                     end

test/distances.jl

@@ -44,6 +44,8 @@ using StringDistances, Unicode, Test
 		@test evaluate(DamerauLevenshtein(), "cape sand recycling ", "edith ann graham") == 17
 		@test evaluate(DamerauLevenshtein(), "jellyifhs", "jellyfish") == 2
 		@test evaluate(DamerauLevenshtein(), "ifhs", "fish") == 2
+		@test DamerauLevenshtein()("abcdef", "abcxyf", 2) == 2
+
 		@test evaluate(DamerauLevenshtein(), [1, 2, 3], [1,2, 4]) == 1
 		@test evaluate(DamerauLevenshtein(), graphemes("alborgów"), graphemes("amoniak")) == evaluate(DamerauLevenshtein(), "alborgów", "amoniak")
 		@test DamerauLevenshtein()("bc", "abc") == 1
@@ -161,7 +163,7 @@ using StringDistances, Unicode, Test
 	# Test with R package StringDist
 	for x in solutions
 		t, solution = x
-		for i in 1:length(solution)
+		for i in eachindex(solution)
 			if isnan(evaluate(t, strings[i]...))
 				@test isnan(solution[i])
 			else
@@ -174,8 +176,19 @@ using StringDistances, Unicode, Test
 	for i in eachindex(strings)
 		@test round(Int, (1 - evaluate(RatcliffObershelp(), strings[i]...)) * 100) ≈ solution[i] atol = 1e-4
 	end
+
+	# test max_dist
+	for i in eachindex(strings)
+		d = Levenshtein()(strings[i]...)
+		@test Levenshtein()(strings[i]..., d) == d
+		d = DamerauLevenshtein()(strings[i]...)
+		@test DamerauLevenshtein()(strings[i]..., d) == d
+	end
 end
 
+d = DamerauLevenshtein()("abcdef", "abcxyf")
+@test DamerauLevenshtein()("abcdef", "abcxyf", d) == d
+
 
 
 #= R test