Phrogz / Liqr

Substring filtering for Lua

Liqr

Substring filtering for Lua.

In general, sequential matches and matches at word boundaries—including the boundaries of capital letters appearing in camelCaseDescriptors—are prioritized over spread out, mid-word matches.

Matching a Single String

local liqr = require('liqr')

local score, matches = liqr.match('Fissile Pitched Birch Oxtail', 'ill')
print(score)
--> 0.55  Lower scores are better
-->       0.0 indicates an exact case-insensitive match

inspect(matches)
--> {
-->    {first=5, last=6},   "il" characters in "Fissile"
-->    {first=28, last=28}  "l" character in "Oxtail"
--> }

-- A failed match returns only a score of infinity
local score, matches = liqr.match('dog', 'cat')
print(score, matches)
--> inf  nil 

Filtering and Sorting a List of Results

local menu = {
    {id=1, label='Topside Betake Bejewel Mouth'},
    {id=2, label='Indigent Wapiti Mail'},
    {id=3, label='Fissile Pitched Birch Oxtail'},
    {id=4, label='Pithy Crumpet Monster'},
    {id=5, label='Britches Courier Small'},
    {id=6, label='Lagrange Exemplar Raisin Clang'},
    {id=7, label='Zoo Beam Diluvium Tourist'},
    {id=8, label='Taffy Town'},
    {id=9, label='Outwash Author Infer Flamingo'},
}


-- Simply finding the names of the matching items
-- The optional third parameter indicates that the items are tables, and matches against this key
-- With no third parameter `tostring()` is invoked on each list entry to find the string to match against
local results = liqr.filter(menu, 'cr', 'label')
for i,match in ipairs(results) do
    print(i, menu[match.originalIndex].label)
end
--> 1	Pithy Crumpet Monster
--> 2	Britches Courier Small List
--> 3	Fissile Pitched Birch Oxtail


-- Showing the data available in the results
local results = liqr.filter(menu, 'bea', 'label')
--> {
-->   {score=0.15, originalIndex=7, matches={{first=5, last=7}},
-->    bits={{match=false, str="Zoo "},
-->          {match=true,  str="Bea"},
-->          {match=false, str="m Diluvium Tourist"}}},
-->
-->   {score=0.4, originalIndex=1, matches={{first=9, last=10}, {first=12, last=12}},
-->    bits={{match=false, str="Topside "},
-->          {match=true,  str="Be"},
-->          {match=false, str="t"},
-->          {match=true,  str="a"},
-->          {match=false, str="ke Bejewel Mouth"}}},
-->
-->   {score=0.55, originalIndex=5, matches={{first=1, last=1}, {first=7, last=7}, {first=20, last=20}},
-->    bits={{match=true,  str="B"},
-->          {match=false, str="ritch"},
-->          {match=true,  str="e"},
-->          {match=false, str="s Courier Sm"},
-->          {match=true,  str="a"},
-->          {match=false, str="ll"}}}}
--> }


-- Showing how to concatenate the `bits` to construct a string that highlights the matches
local function showTop5(search)
    for i,result in ipairs(liqr.filter(menu, search, 'label')) do
        if i>5 then break end
        local uppercasedMatches = {}
        for i,bit in ipairs(result.bits) do
            uppercasedMatches[i] = bit.match and bit.str:upper() or bit.str:lower()
        end
        print(table.concat(uppercasedMatches))
    end
end

showTop5('t')
--> Topside betake bejewel mouth
--> Taffy town
--> zoo beam diluvium Tourist
--> briTches courier small list
--> piThy crumpet monster

showTop5('tt')
--> Taffy Town
--> Topside beTake bejewel mouth
--> zoo beam diluvium TourisT
--> briTches courier small lisT
--> piThy crumpeT monster

showTop5('ttown')
--> Taffy TOWN