lua-utility

[!MIT](https://github.com/xiedacon/lua-utility/blob/master/LICENSE)

Requirements

• cjson

Usage

• Base

  • try

  • noop

  • once

• Array

  • concat

  • diff

  • each

  • every

  • fill

  • filter

  • find

  • findIndex

  • from

  • includes

  • indexOf

  • join

  • lastIndexOf

  • map

  • pop

  • push

  • reduce

  • reduceRight

  • reverse

  • shift

  • slice

  • some

  • sort

  • splice

  • toString

  • union

  • unshift

• Function

  • apply

  • bind

  • call

• Object

  • assign

  • entries

  • freeze

  • get

  • keys

  • omit

  • pick

  • set

  • values

• String

  • endsWith

  • replace

  • slice

  • split

  • startsWith

  • trim

  • trimLeft

  • trimRight

Base

    local resty_redis = require "resty.redis"
    local utility = require "utility"
    
    function get_redis()
        local redis, err = resty_redis:new()
        if not redis then return nil, err end
    
        local ok, err = redis:connect("127.0.0.1", 6379)
    
        if ok then
            return redis 
        else
            return nil, err
        end
    end
    
    function close_redis(res)
        local redis = res[0]
        local data = res[1]
    
        redis:close()
    
        return data
    end
    
    local res, err = utility.try({
        get_redis
        function(red)
            local data, err = redis:get("something")
    
            return { redis, data }, err
        end,
        close_redis
    }, function(err)
        return nil, "some error happened"
    end)
    
    utility.noop() -- nothing happend
    utility.once(function()
        -- only call once
    end)

Array

This api is similar to js Array

    local Array = require "utility.array"
    
    local arr = Array({}) -- {}
    local arr1 = Array({ 1, 2, 3 }) -- { 1, 2, 3 }
    local arr2 = Array.from({ 1, 2, 3 }) -- { 1, 2, 3 }
    
    arr:concat(arr1)
    arr:each(function(value, index, arr) end)
    arr:every(function(value, index, arr) end)
    arr:fill(1)
    arr:filter(function(value, index, arr) end)
    arr:find(function(value, index, arr) end)
    arr:findIndex(function(value, index, arr) end)
    arr:forEach(function(value, index, arr) end)
    arr:includes(1)
    arr:indexOf(1)
    arr:join('-')
    arr:lastIndexOf(1)
    arr:map(function(value, index, arr) end)
    arr:pop()
    arr:push(1)
    arr:reduce(function(result, value, index, arr) end, 0)
    arr:reduceRight(function(result, value, index, arr) end, 0)
    arr:reverse()
    arr:shift()
    arr:slice(0, 1)
    arr:some(function(value, index, arr) end)
    arr:sort(function(value1, value2) end)
    arr:splice(0, 1)
    arr:toString()
    arr:unshift(1)
    arr:diff(arr1) -- arr_only, arr1_only
    arr:union(arr1, arr2) -- arr U arr1 U arr2

Function

    local Function require "utility.function"
    
    local func = Function(function(arg1, arg2, arg3)
        print(arg1 .. " " .. arg2 .. " " .. arg3)
    end)
    
    -- 1 2 3
    func(1, 2, 3)
    -- 1 2 3
    func:apply({ 1, 2, 3 })
    -- 1 2 4
    func:bind(1, 2)(2, 3, 4)
    -- 1 2 2 3 4
    func:call(1, 2, 3)

Object

    local Object = require "utility.array"
    
    -- { a = 2, b = 3, c = 2, d = 3 }
    Object.assign({
        a = 1,
        b = 1
    }, {
        a = 2,
        c = 2
    }, {
        b = 3,
        d = 3
    })
    
    -- { a = 1, b = 1 }
    Object.pick({
        a = 1,
        b = 1,
        c = 1
    }, { "a", "b" })
    
    -- { c = 1 }
    Object.omit({
        a = 1,
        b = 1,
        c = 1
    }, { "a", "b" })
    
    -- 1
    Object.get({
        a = {
            a = 1
        },
        b = 1,
        c = 1
    }, "a.a") -- or { "a", "a" }
    
    -- 0
    Object.get({
        a = 1,
        b = 1,
        c = 1
    }, "a.a", 0)
    
    -- { a = { a = 1 } }
    Object.set({}, "a.a", 1)
    
    -- { a = { a = 1 } }
    Object.set({}, { "a", "a" }, 1)
    
    -- { "a", "b", "c" }
    Object.keys({
        a = 1,
        b = 2,
        c = 3
    })
    
    -- { 1, 2, 3 }
    Object.values({
        a = 1,
        b = 2,
        c = 3
    })
    
    -- { { "a", 1 }, { "b", 2 }, { "c", 3 } }
    Object.entries({
        a = 1,
        b = 2,
        c = 3
    })
    
    local obj = { a = "a" }
    Object.freeze(obj) -- after this, obj is not editable
    
    obj.a = "b" -- { a = "a" }
    obj.b = "b" -- { a = "a" }

String

    local String = require "utility.string"
    
    String.endsWith("test.lua", ".lua") -- true
    String.endsWith("test.lua", ".lu") -- false
    String.replace("test.lua", ".", "-") -- "test-lua"
    String.replace("$a-$b", { a = "aaa", b = "bbb" }) -- "aaa-bbb"
    String.replace("${a}-${b}", { a = "aaa", b = "bbb" }, function(k) return "${" .. k .. "}" end) -- "aaa-bbb"
    String.slice("test.lua", 1, 5) -- test
    String.split("test.lua", ".") -- { "test", "lua" }
    String.startsWith("test.lua", "test") -- true
    String.startsWith("test.lua", "est") -- false
    String.trim("  test.lua  ") -- "test.lua"
    String.trimLeft("  test.lua  ") -- "test.lua  "
    String.trimRight("  test.lua  ") -- "  test.lua"

Tests

    export LUA_PATH="/path/to/lua-utility/lib/?.lua;;"
    export LUA_CPATH="/path/to/lua-cjson/?.so;;"
    
    lua test.lua

License

MIT License

Copyright (c) 2018 xiedacon