forth-stuff/Interpreters.tl

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local ds = require("DataStructures")
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 istream = require("InputStream")
local CoreWords = require("CoreWords")
local Pointer = ds.Pointer
local type Interpreters = record
inner: function(Environment)
outer: function(Environment)
end
function Interpreters.start(env: Environment)
table.insert(env.dictionaries, CoreWords)
local interpreterInstructions = {}
table.insert(interpreterInstructions, Interpreters.outer)
table.insert(interpreterInstructions, helpers.reset)
table.insert(env.recognizers, helpers.recNumber)
table.insert(env.recognizers, helpers.recWord)
local startPointer = Pointer:new()
startPointer.referant = interpreterInstructions
env.instructionPointer = startPointer
Interpreters.inner(env)
end
function selectRecXT(env: Environment): function(Environment)
local dataStack = env.activeDataStack
if env.compileState then
dataStack:pop()
local selected = dataStack:pop()
dataStack:pop()
return selected as function(Environment)
else
dataStack:pop()
dataStack:pop()
return dataStack:pop() as function(Environment)
end
end
function Interpreters.outer(env: Environment)
local dataStack = env.activeDataStack
skipWhitespace(env)
local token: string | nil = parseToken(env)
if not token then
env.running = false
return
end
for _, rec in ipairs(env.recognizers) do
dataStack:push(token)
rec(env)
local result = dataStack:pop() as boolean
if not result then
token = dataStack:pop() as string
end
if result then
(selectRecXT(env))(env)
return
end
end
-- We did not recognize the token.
io.write("\""..token.."\"?\n")
end
function Interpreters.inner(env: Environment)
while(env.running) do
env.instructionPointer:deref() as function(Environment)(env)
env.instructionPointer:inc()
end
end
return Interpreters