Support const keyword

1 files changed, 18 insertions, 0 deletions

diff --git a/lib/lexer.mll b/lib/lexer.mll
index e0c5453..6e9b975 100644
--- a/lib/lexer.mll
+++ b/lib/lexer.mll
@@ -23,6 +23,7 @@ rule read =
   | "_int" { INTSYMBOL } 
   | "(" { LBRACE }
   | ")" { RBRACE }
+  | '"' { read_string (Buffer.create 20) lexbuf }
   | int { INT (Lexing.lexeme lexbuf |> int_of_string) }
   | white { read lexbuf } 
   | ":" { COLON }
@@ -32,3 +33,20 @@ rule read =
   | "." { DOT }
   | eof { EOF } 
 	| _ as c { failwith (Printf.sprintf "unexpected character: %C" c) }
+
+and read_string buf =
+  parse
+  | '"'       { STRING (Buffer.contents buf) }
+  | '\\' '/'  { Buffer.add_char buf '/'; read_string buf lexbuf }
+  | '\\' '\\' { Buffer.add_char buf '\\'; read_string buf lexbuf }
+  | '\\' 'b'  { Buffer.add_char buf '\b'; read_string buf lexbuf }
+  | '\\' 'f'  { Buffer.add_char buf '\012'; read_string buf lexbuf }
+  | '\\' 'n'  { Buffer.add_char buf '\n'; read_string buf lexbuf }
+  | '\\' 'r'  { Buffer.add_char buf '\r'; read_string buf lexbuf }
+  | '\\' 't'  { Buffer.add_char buf '\t'; read_string buf lexbuf }
+  | [^ '"' '\\']+
+    { Buffer.add_string buf (Lexing.lexeme lexbuf);
+      read_string buf lexbuf
+    }
+  | _ { raise (SyntaxError ("Illegal string character: " ^ Lexing.lexeme lexbuf)) }
+  | eof { raise (SyntaxError ("String is not terminated")) }