The check from rifleh700

Description

Simple Lua/MTA argument type checking lib for MTA:SA.

API

Functions

boolean check(string patern) Check function arguments by pattern. It causes an error "bad argument" if the check failed, otherwise returns 'true'.
boolean scheck(string pattern) Soft check function arguments by pattern. It causes a warning "bad argument" and returns 'false' if the check failed, otherwise returns 'true'.
boolean warn(string msg [, int lvl = 1]) Cause a warning. Unlike 'error', doesn't terminate the function. Unlike outputDebugString, u can define Lua warning lvl.

Variables

table checkers Table of user custom checkers.

How to use

Patterns

Lua types shortcuts

Use types shortcuts instead full type names:

check("boolean") -- сheck whether the arg #1 is a boolean
check("b") -- same
  
check("nil") -- nil type doesn't have shortcut
  
check("number")
check("n")
  
check("string")
check("s")
  
check("table")
check("t")
  
check("userdata")
check("u")
  
check("function")
check("f")
  
check("thread")
check("th")

Multiple args

Use as many arguments types as you need:

check("s,n,t") -- #1 - string, #2 - number, #3 - table

Special symbols

Use 'any' type by '?' symbol or 'notnil' type by '!' symbol:

check("s,?,t") -- #1 - string, #2 - any type, #3 - table
check("s,n,!") -- #1 - string, #2 - number, #3 - any type but NOT nil

Optional args

Use optional arguments by '?' symbol:

check("s,?n,t") -- #1 - string, #2 - nil or number(optional argument), #3 - table

Type variants

Use two or more variants of type separated by '|' symbol:

check("nil|s,n,t") -- #1 - nil or string(optional argument), #2 - number, #3 - table
check("?s,n,t") -- same
check("s|n|t,t") -- #1 - string or number or table, #2 - table
check("?s|n|t,t") -- #1 - nil or string or number or table(optional argument), #2 - table

Type repeat

Use two or more same types by '[n]' block:

check("s,n[2],t") -- #1 - string, #2 - number, #3 - number, #4 - table
check("s,b|n[2],t") -- #1 - string, #2 - boolean or number, #3 - boolean or number, #4 - table
check("s,?b|n[2],t") -- #1 - string, #2 - nil or boolean or number(optional argument), #3 - nil or boolean or number(optional argument), #4 - table

Metatable types

Use metatable types

function f(c)
    check("color")
    return true
end

function test()
    local red = setmetatable({255, 0, 0}, {__type = "color"})
    iprint(f(red)) -- true
end

MTA types

Use userdata MTA types as subtypes of 'userdata':

check("u:acl-group") -- #1 - acl-group
check("u:lua-timer") -- #1 - timer

Use MTA element types as subtypes of 'userdata:element':

check("u:element:vehicle") -- #1 - vehicle element
check("u:element:player|u:element:ped") -- #1 - player element or ped element

GUI elements default checker is available:

check("userdata:element:gui") -- #1 - any MTA gui element (button, label, gridlist, etc...)
check("u:element:gui") -- same

Check

Hard check

It causes Lua error "bad argument" if the check failed:

function f(str, num, data)
    check("s,?n,t") -- #1 - string, #2 - nil or number(optional argument), #3 - table
    return true
end

function test()
    iprint(f("lol", 1, {})) -- true
    iprint(f("lol", nil, {})) -- true
    iprint(f("lol", nil, nil)) -- error: bad argument #3 'data' to 'f' (table expected, got nil)
end

Soft check

It causes a warning "bad argument" and returns 'false' if the check failed, otherwise returns 'true':

function f(str, num, data)
    if not scheck("s,?n,t") then return false end
    return true
end

function test()
    iprint(f("lol", 1, {})) -- true
    iprint(f("lol", nil, {})) -- true
    iprint(f("lol", nil, nil)) -- false, warning: bad argument #3 'data' to 'f' (table expected, got nil)
end

Custom checkers

Define your own checkers:

function f(num)
    check("percent")
    return true
end

function test()
    checkers.percent = function(v) return type(v) == "number" and v >= 0 and v <= 1 end
    iprint(f(0.1)) -- true
    iprint(f(1)) -- true
    iprint(f(1.1)) -- error: bad argument #1 'num' to 'f' (percent expected, got number)
end

Warnings

Use warnings instead errors wherever you need:

function f()
    warn("something is wrong, but that's all right", 2)
    return true
end

function test()
    iprint(f()) -- true, warning: something is wrong, but that's all right
end

rifleh700 / check Goto Github PK

check's Introduction