1 files changed, 156 insertions, 0 deletions
diff --git a/Data/BuiltIn/Libraries/lua-stdlib/debug.lua b/Data/BuiltIn/Libraries/lua-stdlib/debug.lua
new file mode 100644
index 0000000..cab29ff
--- /dev/null
+++ b/Data/BuiltIn/Libraries/lua-stdlib/debug.lua
@@ -0,0 +1,156 @@
+--[[
+ 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)