Somewhat working lambdas

Architectural changes to lambda evaluation and parsing to allow
for correct expression evaluation. Contains several failing AI-generated
tests and we're still failing tests for erroring incomplete definitions

src/Lexer.hs

@@ -7,6 +7,7 @@ import Data.Void
 import qualified Data.Set as Set
 
 type Lexer = Parsec Void String
+
 data LToken
   = LKeywordT
   | LIdentifier String
@@ -44,7 +45,7 @@ stringLiteral = do
   if null content
     then fail "Empty string literals are not allowed"
     else do
-      char '"' -- "
+      char '"'
       return (LStringLiteral content)
 
 assign :: Lexer LToken
@@ -92,5 +93,5 @@ saplingLexer = many (sc *> choice
 
 lexSapling :: String -> [LToken]
 lexSapling input = case runParser saplingLexer "" input of
-  Left err  -> error $ "Lexical error:\n" ++ errorBundlePretty err
+  Left err -> error $ "Lexical error:\n" ++ errorBundlePretty err
   Right tokens -> tokens