--[[ The MIT License (MIT) Copyright (c) 2020 Seth Warn Permission is hereby granted, free of charge, to any person obtaining a copyof this software and associated documentation files (the "Software"), to dealin the Software without restriction, including without limitation the rightsto use, copy, modify, merge, publish, distribute, sublicense, and/or sellcopies of the Software, and to permit persons to whom the Software isfurnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included inall copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS ORIMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THEAUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHERLIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS INTHE SOFTWARE. ]] -- The lua implementation of the fzy string matching algorithm local SCORE_GAP_LEADING = -0.005local SCORE_GAP_TRAILING = -0.005local SCORE_GAP_INNER = -0.01local SCORE_MATCH_CONSECUTIVE = 1.0local SCORE_MATCH_SLASH = 0.9local SCORE_MATCH_WORD = 0.8local SCORE_MATCH_CAPITAL = 0.7local SCORE_MATCH_DOT = 0.6local SCORE_MAX = math.hugelocal SCORE_MIN = -math.hugelocal MATCH_MAX_LENGTH = 1024 local fzy = {} -- Check if `needle` is a subsequence of the `haystack`.---- Usually called before `score` or `positions`.---- Args:-- needle (string)-- haystack (string)-- case_sensitive (bool, optional): defaults to false---- Returns:-- boolfunction fzy.has_match(needle, haystack, case_sensitive) if not case_sensitive then needle = string.lower(needle) haystack = string.lower(haystack) end local j = 1 for i = 1, string.len(needle) do j = string.find(haystack, needle:sub(i, i), j, true) if not j then return false else j = j + 1 end end return trueend local function is_lower(c) return c:match("%l")end local function is_upper(c) return c:match("%u")end local function precompute_bonus(haystack) local match_bonus = {} local last_char = "/" for i = 1, string.len(haystack) do local this_char = haystack:sub(i, i) if last_char == "/" or last_char == "\\" then match_bonus[i] = SCORE_MATCH_SLASH elseif last_char == "-" or last_char == "_" or last_char == " " then match_bonus[i] = SCORE_MATCH_WORD elseif last_char == "." then match_bonus[i] = SCORE_MATCH_DOT elseif is_lower(last_char) and is_upper(this_char) then match_bonus[i] = SCORE_MATCH_CAPITAL else match_bonus[i] = 0 end last_char = this_char end return match_bonusend local function compute(needle, haystack, D, M, case_sensitive) -- Note that the match bonuses must be computed before the arguments are -- converted to lowercase, since there are bonuses for camelCase. local match_bonus = precompute_bonus(haystack) local n = string.len(needle) local m = string.len(haystack) if not case_sensitive then needle = string.lower(needle) haystack = string.lower(haystack) end -- Because lua only grants access to chars through substring extraction, -- get all the characters from the haystack once now, to reuse below. local haystack_chars = {} for i = 1, m do haystack_chars[i] = haystack:sub(i, i) end for i = 1, n do D[i] = {} M[i] = {} local prev_score = SCORE_MIN local gap_score = i == n and SCORE_GAP_TRAILING or SCORE_GAP_INNER local needle_char = needle:sub(i, i) for j = 1, m do if needle_char == haystack_chars[j] then local score = SCORE_MIN if i == 1 then score = ((j - 1) * SCORE_GAP_LEADING) + match_bonus[j] elseif j > 1 then local a = M[i - 1][j - 1] + match_bonus[j] local b = D[i - 1][j - 1] + SCORE_MATCH_CONSECUTIVE score = math.max(a, b) end D[i][j] = score prev_score = math.max(score, prev_score + gap_score) M[i][j] = prev_score else D[i][j] = SCORE_MIN prev_score = prev_score + gap_score M[i][j] = prev_score end end endend -- Compute a matching score.---- Args:-- needle (string): must be a subequence of `haystack`, or the result is-- undefined.-- haystack (string)-- case_sensitive (bool, optional): defaults to false---- Returns:-- number: higher scores indicate better matches. See also `get_score_min`-- and `get_score_max`.function fzy.score(needle, haystack, case_sensitive) local n = string.len(needle) local m = string.len(haystack) if n == 0 or m == 0 or m > MATCH_MAX_LENGTH or n > m then return SCORE_MIN elseif n == m then return SCORE_MAX else local D = {} local M = {} compute(needle, haystack, D, M, case_sensitive) return M[n][m] endend -- Compute the locations where fzy matches a string.---- Determine where each character of the `needle` is matched to the `haystack`-- in the optimal match.---- Args:-- needle (string): must be a subequence of `haystack`, or the result is-- undefined.-- haystack (string)-- case_sensitive (bool, optional): defaults to false---- Returns:-- {int,...}: indices, where `indices[n]` is the location of the `n`th-- character of `needle` in `haystack`.-- number: the same matching score returned by `score`function fzy.positions(needle, haystack, case_sensitive) local n = string.len(needle) local m = string.len(haystack) if n == 0 or m == 0 or m > MATCH_MAX_LENGTH or n > m then return {}, SCORE_MIN elseif n == m then local consecutive = {} for i = 1, n do consecutive[i] = i end return consecutive, SCORE_MAX end local D = {} local M = {} compute(needle, haystack, D, M, case_sensitive) local positions = {} local match_required = false local j = m for i = n, 1, -1 do while j >= 1 do if D[i][j] ~= SCORE_MIN and (match_required or D[i][j] == M[i][j]) then match_required = (i ~= 1) and (j ~= 1) and ( M[i][j] == D[i - 1][j - 1] + SCORE_MATCH_CONSECUTIVE) positions[i] = j j = j - 1 break else j = j - 1 end end end return positions, M[n][m]end -- Apply `has_match` and `positions` to an array of haystacks.---- Args:-- needle (string)-- haystack ({string, ...})-- case_sensitive (bool, optional): defaults to false---- Returns:-- {{idx, positions, score}, ...}: an array with one entry per matching line-- in `haystacks`, each entry giving the index of the line in `haystacks`-- as well as the equivalent to the return value of `positions` for that-- line.function fzy.filter(needle, haystacks, case_sensitive) local result = {} for i, line in ipairs(haystacks) do if fzy.has_match(needle, line, case_sensitive) then local p, s = fzy.positions(needle, line, case_sensitive) table.insert(result, {i, p, s}) end end return resultend -- The lowest value returned by `score`.---- In two special cases:-- - an empty `needle`, or-- - a `needle` or `haystack` larger than than `get_max_length`,-- the `score` function will return this exact value, which can be used as a-- sentinel. This is the lowest possible score.function fzy.get_score_min() return SCORE_MINend -- The score returned for exact matches. This is the highest possible score.function fzy.get_score_max() return SCORE_MAXend -- The maximum size for which `fzy` will evaluate scores.function fzy.get_max_length() return MATCH_MAX_LENGTHend -- The minimum score returned for normal matches.---- For matches that don't return `get_score_min`, their score will be greater-- than than this value.function fzy.get_score_floor() return MATCH_MAX_LENGTH * SCORE_GAP_INNERend -- The maximum score for non-exact matches.---- For matches that don't return `get_score_max`, their score will be less than-- this value.function fzy.get_score_ceiling() return MATCH_MAX_LENGTH * SCORE_MATCH_CONSECUTIVEend -- The name of the currently-running implmenetation, "lua" or "native".function fzy.get_implementation_name() return "lua"end return fzy
--[[ The MIT License (MIT)
Copyright (c) 2020 Seth Warn
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE. ]]
-- The lua implementation of the fzy string matching algorithm
local SCORE_GAP_LEADING = -0.005
local SCORE_GAP_TRAILING = -0.005
local SCORE_GAP_INNER = -0.01
local SCORE_MATCH_CONSECUTIVE = 1.0
local SCORE_MATCH_SLASH = 0.9
local SCORE_MATCH_WORD = 0.8
local SCORE_MATCH_CAPITAL = 0.7
local SCORE_MATCH_DOT = 0.6
local SCORE_MAX = math.huge
local SCORE_MIN = -math.huge
local MATCH_MAX_LENGTH = 1024
local fzy = {}
-- Check if `needle` is a subsequence of the `haystack`.
--
-- Usually called before `score` or `positions`.
--
-- Args:
-- needle (string)
-- haystack (string)
-- case_sensitive (bool, optional): defaults to false
--
-- Returns:
-- bool
function fzy.has_match(needle, haystack, case_sensitive)
if not case_sensitive then
needle = string.lower(needle)
haystack = string.lower(haystack)
end
local j = 1
for i = 1, string.len(needle) do
j = string.find(haystack, needle:sub(i, i), j, true)
if not j then
return false
else
j = j + 1
end
end
return true
end
local function is_lower(c)
return c:match("%l")
end
local function is_upper(c)
return c:match("%u")
end
local function precompute_bonus(haystack)
local match_bonus = {}
local last_char = "/"
for i = 1, string.len(haystack) do
local this_char = haystack:sub(i, i)
if last_char == "/" or last_char == "\\" then
match_bonus[i] = SCORE_MATCH_SLASH
elseif last_char == "-" or last_char == "_" or last_char == " " then
match_bonus[i] = SCORE_MATCH_WORD
elseif last_char == "." then
match_bonus[i] = SCORE_MATCH_DOT
elseif is_lower(last_char) and is_upper(this_char) then
match_bonus[i] = SCORE_MATCH_CAPITAL
else
match_bonus[i] = 0
end
last_char = this_char
end
return match_bonus
end
local function compute(needle, haystack, D, M, case_sensitive)
-- Note that the match bonuses must be computed before the arguments are
-- converted to lowercase, since there are bonuses for camelCase.
local match_bonus = precompute_bonus(haystack)
local n = string.len(needle)
local m = string.len(haystack)
if not case_sensitive then
needle = string.lower(needle)
haystack = string.lower(haystack)
end
-- Because lua only grants access to chars through substring extraction,
-- get all the characters from the haystack once now, to reuse below.
local haystack_chars = {}
for i = 1, m do
haystack_chars[i] = haystack:sub(i, i)
end
for i = 1, n do
D[i] = {}
M[i] = {}
local prev_score = SCORE_MIN
local gap_score = i == n and SCORE_GAP_TRAILING or SCORE_GAP_INNER
local needle_char = needle:sub(i, i)
for j = 1, m do
if needle_char == haystack_chars[j] then
local score = SCORE_MIN
if i == 1 then
score = ((j - 1) * SCORE_GAP_LEADING) + match_bonus[j]
elseif j > 1 then
local a = M[i - 1][j - 1] + match_bonus[j]
local b = D[i - 1][j - 1] + SCORE_MATCH_CONSECUTIVE
score = math.max(a, b)
end
D[i][j] = score
prev_score = math.max(score, prev_score + gap_score)
M[i][j] = prev_score
else
D[i][j] = SCORE_MIN
prev_score = prev_score + gap_score
M[i][j] = prev_score
end
end
end
end
-- Compute a matching score.
--
-- Args:
-- needle (string): must be a subequence of `haystack`, or the result is
-- undefined.
-- haystack (string)
-- case_sensitive (bool, optional): defaults to false
--
-- Returns:
-- number: higher scores indicate better matches. See also `get_score_min`
-- and `get_score_max`.
function fzy.score(needle, haystack, case_sensitive)
local n = string.len(needle)
local m = string.len(haystack)
if n == 0 or m == 0 or m > MATCH_MAX_LENGTH or n > m then
return SCORE_MIN
elseif n == m then
return SCORE_MAX
else
local D = {}
local M = {}
compute(needle, haystack, D, M, case_sensitive)
return M[n][m]
end
end
-- Compute the locations where fzy matches a string.
--
-- Determine where each character of the `needle` is matched to the `haystack`
-- in the optimal match.
--
-- Args:
-- needle (string): must be a subequence of `haystack`, or the result is
-- undefined.
-- haystack (string)
-- case_sensitive (bool, optional): defaults to false
--
-- Returns:
-- {int,...}: indices, where `indices[n]` is the location of the `n`th
-- character of `needle` in `haystack`.
-- number: the same matching score returned by `score`
function fzy.positions(needle, haystack, case_sensitive)
local n = string.len(needle)
local m = string.len(haystack)
if n == 0 or m == 0 or m > MATCH_MAX_LENGTH or n > m then
return {}, SCORE_MIN
elseif n == m then
local consecutive = {}
for i = 1, n do
consecutive[i] = i
end
return consecutive, SCORE_MAX
end
local D = {}
local M = {}
compute(needle, haystack, D, M, case_sensitive)
local positions = {}
local match_required = false
local j = m
for i = n, 1, -1 do
while j >= 1 do
if D[i][j] ~= SCORE_MIN and (match_required or D[i][j] == M[i][j]) then
match_required = (i ~= 1) and (j ~= 1) and (
M[i][j] == D[i - 1][j - 1] + SCORE_MATCH_CONSECUTIVE)
positions[i] = j
j = j - 1
break
else
j = j - 1
end
end
end
return positions, M[n][m]
end
-- Apply `has_match` and `positions` to an array of haystacks.
--
-- Args:
-- needle (string)
-- haystack ({string, ...})
-- case_sensitive (bool, optional): defaults to false
--
-- Returns:
-- {{idx, positions, score}, ...}: an array with one entry per matching line
-- in `haystacks`, each entry giving the index of the line in `haystacks`
-- as well as the equivalent to the return value of `positions` for that
-- line.
function fzy.filter(needle, haystacks, case_sensitive)
local result = {}
for i, line in ipairs(haystacks) do
if fzy.has_match(needle, line, case_sensitive) then
local p, s = fzy.positions(needle, line, case_sensitive)
table.insert(result, {i, p, s})
end
end
return result
end
-- The lowest value returned by `score`.
--
-- In two special cases:
-- - an empty `needle`, or
-- - a `needle` or `haystack` larger than than `get_max_length`,
-- the `score` function will return this exact value, which can be used as a
-- sentinel. This is the lowest possible score.
function fzy.get_score_min()
return SCORE_MIN
end
-- The score returned for exact matches. This is the highest possible score.
function fzy.get_score_max()
return SCORE_MAX
end
-- The maximum size for which `fzy` will evaluate scores.
function fzy.get_max_length()
return MATCH_MAX_LENGTH
end
-- The minimum score returned for normal matches.
--
-- For matches that don't return `get_score_min`, their score will be greater
-- than than this value.
function fzy.get_score_floor()
return MATCH_MAX_LENGTH * SCORE_GAP_INNER
end
-- The maximum score for non-exact matches.
--
-- For matches that don't return `get_score_max`, their score will be less than
-- this value.
function fzy.get_score_ceiling()
return MATCH_MAX_LENGTH * SCORE_MATCH_CONSECUTIVE
end
-- The name of the currently-running implmenetation, "lua" or "native".
function fzy.get_implementation_name()
return "lua"
end
return fzy