darkrc/bin/=

#!/usr/bin/env luajit

local env = setmetatable({}, {__index = function(self, key)
	return math[key] or _G[key] or nil
end})

env.banner = [[
Calculator (by DarkWiiPlayer)
License: the Unlicense (type 'license')
]]

env.help = [[
This is a simple terminal calculator written in Lua.
Call without arguments for an interactive shell.
Call with `-` argument for a multiline calculation.
Call with any other argument for inline calculation.
]]

env.license = [[
This is free and unencumbered software released into the public domain.

Anyone is free to copy, modify, publish, use, compile, sell, or
distribute this software, either in source code form or as a compiled
binary, for any purpose, commercial or non-commercial, and by any
means.

In jurisdictions that recognize copyright laws, the author or authors
of this software dedicate any and all copyright interest in the
software to the public domain. We make this dedication for the benefit
of the public at large and to the detriment of our heirs and
successors. We intend this dedication to be an overt act of
relinquishment in perpetuity of all present and future rights to this
software under copyright law.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.
]]

local moonscript = pcall(function()
	require 'moonscript.base'
end)

if moonscript then
	parse = require('moonscript.base').to_lua
else
	print("Could not load Moonscript, falling back to Lua...")
	parse = function(...) return ... end
end

local function run(line, name, addreturn)
	if addreturn~=false and not moonscript then
		line = "return ("..line..")"
	end
	local expression = assert(load(parse(line), name, 't', env))
	success, math.ans = xpcall(expression, print)
	print(math.ans)
end

local line = table.concat({...}, ' ')

if line == '' then
	print(banner)
	io.write '> '
	for line in io.stdin:lines() do
		io.write("= ")
		run(line, "User Input", true, "=")
		io.write '> '
	end
	print('os.exit(0, true) -- See you again soon ♥')
elseif line == '-' then
	run(io.stdin:read("*a"), "User Input", false, "=")
else
	run(line, "Commandline")
end