--- lam.repl

local m = {}
local read = require("read")
local eval = require("eval")
local pp = require("pp").pp

local function schemeprint (x)
	-- if x == nil then return end
	if x == true then
		print("#t")
	elseif x == false then
		print("#f")
	else
		print(x)
	end
end

function m.repl (prompt, infile, out)
	-- PROMPT should be a string, INFILE is a filename, and OUT is either a
	-- filename, nil (in which case it will be stdout), or false (which
	-- suppresses output)
	local inport = read.inport(infile)
	if out ~= false then io.output(out) end
	io.output():setvbuf("line")
	if prompt then
		stderr = io.open("/dev/stderr", "w") -- Linux-only !
	end
	while true do
		if prompt then
			stderr:write(prompt)
			stderr:flush()
		end
		local x = read.read(inport)
		if x then
			local val = eval.eval(x)
			if out ~= false then
				schemeprint(val)
			end
		end
	end
	inport:close()
	stderr:close()
	io.output():close()
end

--------
return m