Lua: all steps and self-hosting.

Also some misc docs/TODO updates.

1 files changed, 53 insertions, 0 deletions

diff --git a/lua/env.lua b/lua/env.lua
new file mode 100644
index 0000000..ee19c90
--- /dev/null
+++ b/lua/env.lua
@@ -0,0 +1,53 @@
+local rex = require('rex_pcre')
+local string = require('string')
+local table = require('table')
+local utils = require('utils')
+local types = require('types')
+
+local Env = {}
+
+function Env:new(outer, binds, exprs)
+    local data = {}
+    local newObj = {outer = outer, data = data}
+    self.__index = self
+    if binds then
+        for i, b in ipairs(binds) do
+            if binds[i].val == '&' then
+                local new_exprs = types.List:new()
+                for j = i, #exprs do
+                    table.insert(new_exprs, exprs[j])
+                end
+                table.remove(exprs, 1)
+                data[binds[i+1].val] = new_exprs
+                break
+            end
+            data[binds[i].val] = exprs[i]
+        end
+    end
+    return setmetatable(newObj, self)
+end
+function Env:find(sym)
+    if self.data[sym.val] ~= nil then
+        return self
+    else
+        if self.outer ~= nil then
+            return self.outer:find(sym)
+        else
+            return nil
+        end
+    end
+end
+function Env:set(sym,val)
+    self.data[sym.val] = val
+    return val
+end
+function Env:get(sym)
+    local env = self:find(sym)
+    if env then
+        return env.data[sym.val]
+    else
+        types.throw("'"..sym.val.."' not found")
+    end
+end
+
+return Env