lua-utility

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