Handle lowercase variable names

M100 BASIC barfs with a syntax error if presented with a lowercase
variable name in a tokenized file.

Fortunately, the fix was easy: since the lexer is already matching all
BASIC keywords plus strings, remarks, and data statements, the only
thing left was variables. So, all we have to do is use
yyput(toupper()) instead of the default ECHO.

Author: hackerb9

m100-tokenize.lex

@@ -6,7 +6,10 @@
  *			gcc lex.tokenize.c
  */
 
+  #include <ctype.h>		/* For toupper() */
+
 %option prefix="tokenize"
+%option case-insensitive
 
 /* Define states that simply copy text instead of lexing */  
 %x string
@@ -51,6 +54,7 @@
     yyterminate();
   }
 
+  /* Table of tokens, case-insensitive due to %option above. */
 END		yyput(128);
 FOR		yyput(129);
 NEXT		yyput(130);
@@ -181,6 +185,17 @@ ASC		yyput(249);
 "MID$"		yyput(254);
 "'"		yyput(':'); yyput(0x8E); yyput(0xFF); BEGIN(remark);
 
+
+   /* Anything not yet matched is a variable name, so capitalize it. */
+<INITIAL>.	{
+    char *yptr = yytext;
+    while ( *yptr )
+       yyput( toupper( *yptr++ ) );
+}
+
+
+
+
 %%
 
 /* The main() routine, yyput(), fixup_ptrs() */