Special-case '.', '...', '+', '-'

1 files changed, 16 insertions, 2 deletions

@@ -95,6 +95,11 @@ local consume_symbol = consume_token
 
 local function consume_number (chars)
         local digits, chars = consume_token(chars)
+        -- The signs by themselves are symbols, as well as '...'
+        if digits:match("[-+.]") or digits == "..." then
+                return digits, chars
+        end
+        -- Otherwise try converting the digits to a number
         local num = tonumber(digits)
         if num == nil then error("Bad number: " .. num) end
         return num, chars
@@ -121,7 +126,6 @@ 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,
         -- ["#"] = ...,
@@ -139,9 +143,19 @@ function read.scan (chars)
                                 return token, toktype
                         elseif chars[1]:match("%s") then
                                 chars = consume_whitespace(chars)
-                        elseif chars[1]:match("[%d-]") then
+                        elseif chars[1]:match("%d") then
                                 token, chars = consume_number(chars)
                                 return token, "number"
+                        elseif chars[1]:match("[.+-]") then
+                                -- special casing for ., ..., +, -
+                                token, chars = consume_number(chars)
+                                if token == "." then
+                                        return token, "dot"
+                                elseif token == "..." then
+                                        return token, "symbol"
+                                else
+                                        return token, "number"
+                                end
                         else
                                 token, chars = consume_symbol(chars)
                                 return token, "symbol"