inputstream changes; curr never reads from after the string

CoreHelpers.tl

@@ -11,7 +11,7 @@ function CoreHelpers.defineWord(dict: Dictionary, str: string, func: function(En
 end
 
 function CoreHelpers.standardInputRefill(): string
-	local input = io.read().."\n"
+	local input = io.read().."\n\n"
 	return input
 end
 
@@ -30,7 +30,7 @@ end
 function CoreHelpers._fileRefill(fname: string): function(): string
 	local f = assert(io.open(fname, "r"))
 	return function(): string
-		local chunk = f:read(2^13)
+		local chunk = f:read(2^3)
 		if not chunk then chunk = "" end
 		return chunk
 	end

InputStream.tl

@@ -14,6 +14,13 @@ end
 local istream_mt = {__index = InputStream}
 
 function InputStream:_manageBuffer()
+	local length = 0
+	if self.str then
+		length = #self.str
+	else
+		length = -1
+	end
+	print("self.str = ",self.str, self.offset,length)
 	if not self.str then
 		self.str = self.refill()
 		self.offset = 1
@@ -48,20 +55,27 @@ end
 -- setters/getters
 function InputStream:__setRefill(func: function(): string)
 	self.refill = func
+	print("setrefill")
 	self:_manageBuffer()
 end
 
 -- 
 function InputStream:curr(): string | nil
+	if self.offset > #self.str then
 		self:_manageBuffer()
-	if #self.str > 0 then
+	end
+	if #self.str > 0 and self.offset < #self.str + 1 then
 		return self.str:sub(self.offset, self.offset)
 	end
 	return nil
 end
 
 function InputStream:next(): string | nil
+	print("next")
+	if self.offset > #self.str then
 		self:_manageBuffer()
+	end
+
 	local current_char: string | nil = nil
 	if #self.str > 0 then
 		current_char = self.str:sub(self.offset, self.offset)

tests.lua

@@ -78,6 +78,7 @@ describe("InputStream tests", function()
       it("handles multiple lines", function()
          local inputstr = "TEST\nTEST\nTEST\nTEST\nTEST\nTEST51515151"
          input = CoreHelpers.oneReadInputStream(inputstr)
+         input:curr()
          for i = 1, #inputstr do
             assert.are.same(inputstr:sub(i, i), input:next())
          end