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StringDistances.jl
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Update edit.jl

compathelper/new_version/2020-10-08-17-05-17-769-1797568811
matthieugomez 2020-07-13 08:56:34 -07:00
parent 26221a13ed
commit 77afc0d4fb
1 changed files with 21 additions and 22 deletions
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src/edit.jl
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@ -14,7 +14,6 @@ where ``m`` is the number of matching characters and
struct Jaro <: SemiMetric end
## http://alias-i.com/lingpipe/docs/api/com/aliasi/spell/JaroWinklerDistance.html
## accepts any iterator, including AbstractString
function (dist::Jaro)(s1, s2)
((s1 === missing) | (s2 === missing)) && return missing
s1, s2 = reorder(s1, s2)
@ -61,14 +60,13 @@ substitutions of a single character) required to change one string into the othe
struct Levenshtein <: Metric end
## Source: http://blog.softwx.net/2014/12/optimizing-levenshtein-algorithm-in-c.html
# Return max_value + 1 if distance higher than max_value
# This makes it possible to differentiate distance equalt to max_value vs strictly higher
# This is important for find_all
function (dist::Levenshtein)(s1, s2, max_value::Union{Integer, Nothing} = nothing)
# Return max_dist + 1 if distance higher than max_dist
# to differentiate distance equal to max_dist or not, which is important for find fctions.
function (dist::Levenshtein)(s1, s2, max_dist::Union{Integer, Nothing} = nothing)
((s1 === missing) | (s2 === missing)) && return missing
s1, s2 = reorder(s1, s2)
len1, len2 = length(s1), length(s2)
max_value !== nothing && len2 - len1 > max_value && return max_value + 1
max_dist !== nothing && len2 - len1 > max_dist && return max_dist + 1
# prefix common to both strings can be ignored
k = common_prefix(s1, s2)
k == len1 && return len2 - k
@ -79,19 +77,19 @@ function (dist::Levenshtein)(s1, s2, max_value::Union{Integer, Nothing} = nothin
for (i1, ch1) in enumerate(s1)
i1 <= k && continue
left = current = i1 - k - 1
max_value !== nothing && (value_lb = left - 1)
max_dist !== nothing && (value_lb = left - 1)
for (i2, ch2) in enumerate(s2)
i2 <= k && continue
above, current, left = current, left, v[i2 - k]
if ch1 != ch2
current = min(current, above, left) + 1
end
max_value !== nothing && (value_lb = min(value_lb, left))
max_dist !== nothing && (value_lb = min(value_lb, left))
v[i2 - k] = current
end
max_value !== nothing && value_lb > max_value && return max_value + 1
max_dist !== nothing && value_lb > max_dist && return max_dist + 1
end
max_value !== nothing && current > max_value && return max_value + 1
max_dist !== nothing && current > max_dist && return max_dist + 1
return current
end
@ -114,20 +112,20 @@ the triangle inequality.
struct DamerauLevenshtein <: SemiMetric end
## http://blog.softwx.net/2015/01/optimizing-damerau-levenshtein_15.html
# Return max_value + 1 if distance higher than max_value
function (dist::DamerauLevenshtein)(s1, s2, max_value::Union{Integer, Nothing} = nothing)
# Return max_dist + 1 if distance higher than max_dist
function (dist::DamerauLevenshtein)(s1, s2, max_dist::Union{Integer, Nothing} = nothing)
((s1 === missing) | (s2 === missing)) && return missing
s1, s2 = reorder(s1, s2)
len1, len2 = length(s1), length(s2)
max_value !== nothing && len2 - len1 > max_value && return max_value + 1
max_dist !== nothing && len2 - len1 > max_dist && return max_dist + 1
# prefix common to both strings can be ignored
k = common_prefix(s1, s2)
k == len1 && return len2 - k
v = collect(1:(len2-k))
w = similar(v)
if max_value !== nothing
if max_dist !== nothing
i2_start = k + 1
i2_end = max_value
i2_end = max_dist
end
prevch1, prevch2 = first(s1), first(s2)
current = 0
@ -135,14 +133,15 @@ function (dist::DamerauLevenshtein)(s1, s2, max_value::Union{Integer, Nothing} =
i1 <= k && continue
left = current = i1 - k - 1
nextTransCost = 0
if max_value !== nothing
i2_start += (i1 > 1 + max_value - (len2 - len1)) ? 1 : 0
if max_dist !== nothing
i2_start += (i1 > 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_value cells (upper left is i1)
if (max_value !== nothing) && ((i2 < i2_start) | (i2 > 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)
if (max_dist !== nothing) && ((i2 < i2_start) | (i2 > i2_end))
prevch2 = ch2
else
above, current, left = current, left, v[i2 - k]
@ -150,7 +149,7 @@ function (dist::DamerauLevenshtein)(s1, s2, max_value::Union{Integer, Nothing} =
# left now equals current cost (which will be diagonal at next iteration)
if ch1 != ch2
current = min(left, current, above) + 1
# note that it never happens at i2 = k + 1 because then the two previous characters were equal
# 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)
thisTransCost += 1
current = min(current, thisTransCost)
@ -160,10 +159,10 @@ function (dist::DamerauLevenshtein)(s1, s2, max_value::Union{Integer, Nothing} =
prevch2 = ch2
end
end
max_value !== nothing && v[i1 - k + len2 - len1] > max_value && return max_value + 1
max_dist !== nothing && v[i1 - k + len2 - len1] > max_dist && return max_dist + 1
prevch1 = ch1
end
max_value !== nothing && current > max_value && return max_value + 1
max_dist !== nothing && current > max_dist && return max_dist + 1
return current
end