allow more than strings

src/StringDistances.jl

@@ -17,9 +17,13 @@ include("find.jl")
 ##
 ##############################################################################
 
-evaluate(::StringDistance, ::Missing, ::AbstractString) = missing
-evaluate(::StringDistance, ::AbstractString, ::Missing) = missing
-evaluate(::StringDistance, ::Missing, ::Missing) = missing
+evaluate(::QGramDistance, ::Missing, ::AbstractString) = missing
+evaluate(::QGramDistance, ::AbstractString, ::Missing) = missing
+
+evaluate(::RatcliffObershelp, ::Missing, ::AbstractString) = missing
+evaluate(::RatcliffObershelp, ::AbstractString, ::Missing) = missing
+
+
 
 compare(::Missing, ::AbstractString, ::StringDistance; min_score = 0.0) = missing
 compare(::AbstractString, ::Missing, ::StringDistance; min_score = 0.0) = missing

src/edit.jl

@@ -15,7 +15,8 @@ struct Jaro <: StringDistance end
 
 
 ## http://alias-i.com/lingpipe/docs/api/com/aliasi/spell/JaroWinklerDistance.html
-function evaluate(dist::Jaro, s1::AbstractString, s2::AbstractString)
+function evaluate(dist::Jaro, s1, s2)
+    (ismissing(s1) | ismissing(s2)) && return missing
     s1, s2 = reorder(s1, s2)
     len1, len2 = length(s1), length(s2)
     # if both are empty, m = 0 so should be 1.0 according to wikipedia. 
@@ -85,7 +86,8 @@ struct Levenshtein  <: StringDistance end
 # Return max_dist +1 if distance higher than max_dist
 # This makes it possible to differentiate distance equalt to max_dist vs strictly higher
 # This is important for find_all
-function evaluate(dist::Levenshtein, s1::AbstractString, s2::AbstractString; max_dist = nothing)
+function evaluate(dist::Levenshtein, s1, s2; max_dist = nothing)
+    (ismissing(s1) | ismissing(s2)) && return missing
     s1, s2 = reorder(s1, s2)
     len1, len2 = length(s1), length(s2)
     max_dist !== nothing && len2 - len1 > max_dist && return max_dist + 1
@@ -138,7 +140,8 @@ required to change one string into the other.
 struct DamerauLevenshtein <: StringDistance end
 
 ## http://blog.softwx.net/2015/01/optimizing-damerau-levenshtein_15.html
-function evaluate(dist::DamerauLevenshtein, s1::AbstractString, s2::AbstractString; max_dist = nothing)
+function evaluate(dist::DamerauLevenshtein, s1, s2; max_dist = nothing)
+    (ismissing(s1) | ismissing(s2)) && return missing
     s1, s2 = reorder(s1, s2)
     len1, len2 = length(s1), length(s2)
     max_dist !== nothing && len2 - len1 > max_dist && return max_dist + 1

src/utils.jl

@@ -10,17 +10,20 @@ Base.nextind(s::StringWithLength, i::Int, n::Int = 1) = nextind(s.s, i, n)
 Base.ncodeunits(s::StringWithLength) = ncodeunits(s.s)
 Base.isvalid(s::StringWithLength, i::Int) = isvalid(s.s, i)
 
+
 function reorder(s1::AbstractString, s2::AbstractString)
     s1 = string_with_length(s1)
     s2 = string_with_length(s2)
-    if length(s1) <= length(s2)
-         return s1, s2
-    else
-        return s2, s1
-    end
+    (length(s1) <= length(s2)) ? (s1, s2) : (s2, s1)
 end
 
-function common_prefix(s1::AbstractString, s2::AbstractString)
+function reorder(s1, s2)
+    (length(s1) <= length(s2)) ? (s1, s2) : (s2, s1)
+end
+
+
+
+function common_prefix(s1, s2)
     x1 = iterate(s1)
     x2 = iterate(s2)
     l = 0