first

1 files changed, 59 insertions, 0 deletions

diff --git a/repl.lua b/repl.lua
new file mode 100644
index 0000000..911e7c7
--- /dev/null
+++ b/repl.lua
@@ -0,0 +1,59 @@
+local pprint=require"pprint"
+pprint.setup{show_all=true,use_tostring=true}
+
+local repl_env = {}
+
+-- should use loadstring on 5.1
+-- works on luajit though
+local function load_chunk(s)
+	return load(s,"repl","t")
+end
+
+local function prompt(p)
+	io.write(p)
+	return io.read()
+end
+
+local function read_chunk()
+	-- try with return
+	-- if that doesn't work try without return
+	-- if error ends in <eof> try multiline
+
+	local function try(text)
+		local f, err = load_chunk("return "..text..";")
+		if f then return f end
+
+		local f, err = load_chunk(text)
+		if f then return f end
+
+		if err:sub(-5) == "<eof>" or err:sub(-7) == "'<eof>'" then
+			local nt = text.."\n"..prompt("} ")
+			return try(nt)
+		end
+
+		return f, err
+	end
+	return try(prompt("] "))
+end
+
+local function result(ok,...)
+	if ok then
+		pprint(...)
+	else
+		print("error: "..(...))
+	end
+end
+
+local function msgh(e)
+	return debug.traceback(e,1)
+end
+
+while true do
+	local f,err = read_chunk()
+
+	if not f then
+		print("load error: "..err)
+	else
+		result(xpcall(f,msgh))
+	end
+end