Support dotted lists in reader

2 files changed, 15 insertions, 6 deletions

@@ -121,6 +121,7 @@ read.readtable = {
         ["'"] = function(chars) return pop(chars), "quote", chars end,
         ["`"] = function(chars) return pop(chars), "quote", chars end,
         [","] = function(chars) return pop(chars), "quote", chars end,
+        ["."] = function(chars) return pop(chars), "dot", chars end,
         ["\""] = consume_string,
         [";"] = consume_comment,
         -- ["#"] =
@@ -161,12 +162,20 @@ end
 read.readmacros = {
         open =
                 function (token, tokens)
-                        local L = {}
+                        local L, lt = {}, nil
                         while tokens[1].type ~= "close" do
-                                table.insert(L, read.parse(tokens))
+                                local nt = read.parse(tokens)
+                                -- this isn't .. my /favorite/ implementation,
+                                -- but it works
+                                if nt == "." then
+                                        lt = read.parse(tokens)
+                                        break
+                                else
+                                        table.insert(L, nt)
+                                end
                         end
-                        pop(tokens) -- remove final ")"
-                        return type.List(L)
+                        pop(tokens)     -- remove final ")"
+                        return type.List(L, lt)
                 end,
         close =
                 function (token, tokens)
@@ -115,12 +115,12 @@ function t.isNull (x)
 end
 
 -- Lists are chained Conses ending in Null
-function t.List (items)
+function t.List (items, last)
         local function tolist (base, items)
                 if #items == 0 then return base end
                 return tolist(t.Cons(table.remove(items), base), items)
         end
-        return tolist(t.Null, items)
+        return tolist(last or t.Null, items)
 end
 
 function t.isList (x)