Lua: all steps and self-hosting.

Also some misc docs/TODO updates.

1 files changed, 42 insertions, 0 deletions

diff --git a/lua/step1_read_print.lua b/lua/step1_read_print.lua
new file mode 100755
index 0000000..abd555d
--- /dev/null
+++ b/lua/step1_read_print.lua
@@ -0,0 +1,42 @@
+#!/usr/bin/env lua
+
+local readline = require('readline')
+local utils = require('utils')
+local reader = require('reader')
+local printer = require('printer')
+
+-- read
+function READ(str)
+    return reader.read_str(str)
+end
+
+-- eval
+function EVAL(ast, env)
+    return ast
+end
+
+-- print
+function PRINT(exp)
+    return printer._pr_str(exp, true)
+end
+
+-- repl
+function rep(str)
+    return PRINT(EVAL(READ(str),""))
+end
+
+while true do
+    line = readline.readline("user> ")
+    if not line then break end
+    xpcall(function()
+        print(rep(line))
+    end, function(exc)
+        if exc then
+            if types._malexception_Q(exc) then
+                exc = printer._pr_str(exc.val, true)
+            end
+            print("Error: " .. exc)
+            print(debug.traceback())
+        end
+    end)
+end