--[[

General Lua Libraries for Lua 5.1, 5.2 & 5.3

Copyright (C) 2002-2018 stdlib authors

]]

--[[--

Additions to the core debug module.

The module table returned by `std.debug` also contains all of the entries

from the core debug table. An hygienic way to import this module, then, is

simply to override the core `debug` locally:

local debug = require 'std.debug'

@corelibrary std.debug

]]

local _ENV = require 'std.normalize' {

'debug',

_debug = require 'std._debug',

concat = 'table.concat',

huge = 'math.huge',

max = 'math.max',

merge = 'table.merge',

stderr = 'io.stderr',

}

--[[ =============== ]]--

--[[ Implementation. ]]--

--[[ =============== ]]--

local function say(n, ...)

local level, argt = n, {...}

if type(n) ~= 'number' then

level, argt = 1, {n, ...}

end

if _debug.level ~= huge and

((type(_debug.level) == 'number' and _debug.level >= level) or level <= 1)

then

local t = {}

for k, v in pairs(argt) do

t[k] = str(v)

end

stderr:write(concat(t, '\t') .. '\n')

end

end

local level = 0

local function trace(event)

local t = debug.getinfo(3)

local s = ' >>> '

for i = 1, level do

s = s .. ' '

end

if t ~= nil and t.currentline >= 0 then

s = s .. t.short_src .. ':' .. t.currentline .. ' '

end

t = debug.getinfo(2)

if event == 'call' then

level = level + 1

else

level = max(level - 1, 0)

end

if t.what == 'main' then

if event == 'call' then

s = s .. 'begin ' .. t.short_src

else

s = s .. 'end ' .. t.short_src

end

elseif t.what == 'Lua' then

s = s .. event .. ' ' ..(t.name or '(Lua)') .. ' <' ..

t.linedefined .. ':' .. t.short_src .. '>'

else

s = s .. event .. ' ' ..(t.name or '(C)') .. ' [' .. t.what .. ']'

end

stderr:write(s .. '\n')

end

-- Set hooks according to _debug

if _debug.call then

debug.sethook(trace, 'cr')

end

local M = {

--- Function Environments

-- @section environments

--- Extend `debug.getfenv` to unwrap functables correctly.

-- @function getfenv

-- @tparam int|function|functable fn target function, or stack level

-- @treturn table environment of *fn*

getfenv = getfenv,

--- Extend `debug.setfenv` to unwrap functables correctly.

-- @function setfenv

-- @tparam function|functable fn target function

-- @tparam table env new function environment

-- @treturn function *fn*

setfenv = setfenv,

--- Functions

-- @section functions

--- Print a debugging message to `io.stderr`.

-- Display arguments passed through `std.tostring` and separated by tab

-- characters when `std._debug` hinting is `true` and *n* is 1 or less;

-- or `std._debug.level` is a number greater than or equal to *n*. If

-- `std._debug` hinting is false or nil, nothing is written.

-- @function say

-- @int[opt=1] n debugging level, smaller is higher priority

-- @param ... objects to print(as for print)

-- @usage

-- local _debug = require 'std._debug'

-- _debug.level = 3

-- say(2, '_debug status level:', _debug.level)

say = say,

--- Trace function calls.

-- Use as debug.sethook(trace, 'cr'), which is done automatically

-- when `std._debug.call` is set.

-- Based on test/trace-calls.lua from the Lua distribution.

-- @function trace

-- @string event event causing the call

-- @usage

-- local _debug = require 'std._debug'

-- _debug.call = true

-- local debug = require 'std.debug'

trace = trace,

}

--- Metamethods

-- @section metamethods

--- Equivalent to calling `debug.say(1, ...)`

-- @function __call

-- @see say

-- @usage

-- local debug = require 'std.debug'

-- debug 'oh noes!'

local metatable = {

__call = function(self, ...)

M.say(1, ...)

end,

}

return setmetatable(merge(debug, M), metatable)