fix string lexing

1 files changed, 15 insertions, 2 deletions

diff --git a/lisp.l b/lisp.l
index 329fc0f..ecf91db 100644
--- a/lisp.l
+++ b/lisp.l
@@ -11,7 +11,21 @@ int tcnt = 0;
                 yylval.dval = atof(yytext);
                 printf("%d: NUMBER: %f\n", ++tcnt, yylval.dval);
                 return NUMBER;
-        }
+                }
+
+\"(\\.|[^"\\])*\" {
+                // remove starting and ending quotes
+                int len = yyleng - 2;
+                char *str = (char*)malloc(len + 1);
+                if (!str) { fprintf(stderr, "Out of memory\n"); exit(1); }
+                strncpy(str, yytext + 1, len);
+                str[len] = '\0';
+
+                yylval.strval = str;
+                printf("%d: STRING: \"%s\"\n", ++tcnt, yylval.strval);
+                return STRING;
+                }
+
 [ \t\n]+        { printf("%d: WHITESPACE\n", tcnt); return WHITESPACE; }
 "("             { printf("%d: LPAREN\n", ++tcnt); return LPAREN; }
 ")"             { printf("%d: RPAREN\n", ++tcnt); return RPAREN; }
@@ -20,6 +34,5 @@ int tcnt = 0;
 "-"             { printf("%d: MINUS\n", ++tcnt); return MINUS; }
 "*"             { printf("%d: MULT\n", ++tcnt); return MULT; }
 "/"             { printf("%d: DIV\n", ++tcnt); return DIV; }
-\".*\"          { printf("%d: STRING\n", ++tcnt); return STRING; }
 .               ; // do nothing 
 %%