Scanner: convert strings and numbers to their runtime values

this adds 'Object' and replaces 'Maybe String' with 'Maybe Object' for the literal in 'Token'
ccntrq · Jan 6, 2018 · 3342970 · 3342970
1 parent d3d38bc
commit 3342970
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Showing 3 changed files with 13 additions and 7 deletions.
diff --git a/src/Object.hs b/src/Object.hs
@@ -0,0 +1,3 @@
+module Object where
+
+data Object = Number Double | String String deriving (Show)
diff --git a/src/Scanner.hs b/src/Scanner.hs
@@ -4,6 +4,7 @@ import Util
 
 import Token
 import TokenType
+import Object
 
 import Control.Conditional
 
@@ -106,8 +107,6 @@ identifier = (munchChars isAlphaNumeric) >> do
       Just t -> addToken t
       Nothing -> addToken IDENTIFIER
 
--- TODO:
--- * create runtime value
 number :: Scanner Token
 number = (munchChars isDigit) >> do
     c <- peek
@@ -116,9 +115,6 @@ number = (munchChars isDigit) >> do
         then advance >> munchChars isDigit >> addToken NUMBER
         else addToken NUMBER
 
--- TODO:
--- * strip the quotes
--- * create runtime value
 string :: Scanner Token
 string = scanString >> ifM (isAtEnd) (unterminatedString) (advance >> addToken STRING)
   where
@@ -153,9 +149,15 @@ addToken :: TokenType -> Scanner Token
 addToken t = do
     st <- get
     let lexeme = slice (start st) (current st) (source st)
-    let token = Token t lexeme Nothing (line st)
+    let literal = literalFromLexeme t lexeme
+    let token = Token t lexeme literal (line st)
     put (st {tokens = token : (tokens st)})
     return token
+  where
+    literalFromLexeme :: TokenType -> String -> Maybe Object
+    literalFromLexeme NUMBER l = Just $ Number (read l)
+    literalFromLexeme STRING l = Just $ String ((init . tail) l) -- trim the qoutes
+    literalFromLexeme _ _ = Nothing
 
 isAtEnd :: Scanner Bool
 isAtEnd = do

diff --git a/src/Token.hs b/src/Token.hs
@@ -1,10 +1,11 @@
 module Token where
 
 import TokenType
+import Object
 
 data Token = Token
   { t_type :: TokenType
   , t_lexeme :: String
-  , t_literal :: Maybe String -- TODO: Convert to runtime value
+  , t_literal :: Maybe Object
   , t_line :: Int
   } deriving (Show)
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,3 @@
		module Object where

		data Object = Number Double \| String String deriving (Show)