forth-stuff/ForthInterpreter.tl

local CoreWords = require("CoreWords")
local ds = require("DataStructures")
local istream = require("InputStream")
local Stack, Dictionary, WordInfo, Environment = ds.Stack, ds.Dictionary, ds.WordInfo, ds.Environment
local helpers = require("CoreHelpers")
local isNumber, skipWhitespace, parseToken = helpers.isNumber, helpers.skipWhitespace, helpers.parseToken
local reset = helpers.reset
local machineEnvironment = Environment:new()
local Pointer = ds.Pointer
function standardInputRefill(): string
	local input = io.read().."\n"
	return input
end

local standardInputStream = istream:new(standardInputRefill)

machineEnvironment.activeInputStream = standardInputStream
machineEnvironment.activeDataStack = Stack:new()
table.insert(machineEnvironment.dictionaries, CoreWords)

function outerInterpreter(env: Environment)
	while(true) do
		skipWhitespace(env)
		local token: string = parseToken(env)
		if isNumber(token) then
			env.activeDataStack:push(tonumber(token))
		else
			for i, dictionary in ipairs(env.dictionaries) do
				local wordinfo = dictionary:lookup(token)
				if wordinfo then
					(wordinfo as WordInfo).func(env)
					goto continue
				end
			end
			print(string.format('%q ?', token))
			::continue::
		end
	end
end

function innerInterpreter(env: Environment)
	while(true) do
		(env.instructionPointer:deref() as function(Environment))(env)
		env.instructionPointer:inc()
	end
end

local interpreterInstructions = {outerInterpreter, reset}
local startPointer = Pointer:new()
startPointer.referant = interpreterInstructions
startPointer.index = 0

machineEnvironment.instructionPointer = startPointer


outerInterpreter(machineEnvironment)