repl.lua


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--- lam.repl

local repl = {}
local eval = require "eval"
local read = require "read"
local util = require "util"

function schemestr(x)
	if type(x) == "table" then
		local ts = "(" .. schemestr(util.pop(x))
		for i,v in ipairs(x) do
			ts = string.format("%s %s", ts, schemestr(v))
		end
		ts = ts .. ")"
		return ts
	elseif x == true then
		return "#t"
	elseif x == false then
		return "#f"
	else
		return tostring(x)
	end
end

function repl.repl (prompt)
	prompt = prompt or "lam> "
	repeat
		io.write(prompt)
		io.output():flush()
		input = io.read()
		if input == ",q" or input == ",quit" then
			break
		else
			val = eval(read(input))
			if val then print(schemestr(val)) end
		end
	until false
end

---
return repl