cameo: various scanner and parser fixes

- README, lang.y: changed depth parameter of "z" command to position
  (sign changes)
- lang.l: defer FILENAME after "gerber" and "gnuplot", so that we don't
  mis-read the number
- lang.l, lang.y: return the reference point after "align" as new token
  REF, not as NUMEBER, so that we can catch syntax errors that would
  cause scanner and parser to become unsynchronized
- lang.l: accept negative numbers
- lang.l: added support for comments beginning with #

cameo/README

@@ -73,7 +73,7 @@ Horizontal adjustments:
 
 Vertical adjustment:
 
-  z [<z0>] <z0-depth>
+  z [<z0>] <z0-pos>
   
 Tool compensation:
 

cameo/lang.l

@@ -22,6 +22,8 @@ void yyerror(const char *s);
 
 static int lineno = 1;
 static int metric = 1;
+static int file_name_follows = 0;
+
 
 #define	MIL2MM(mil)	((mil)/1000*25.4)
 
@@ -34,7 +36,7 @@ static int metric = 1;
    conversion */
 %s DIGIT
 
-NUM	[0-9]+\.?[0-9]*
+NUM	-?[0-9]+\.?[0-9]*
 
 %%
 
@@ -48,9 +50,9 @@ NUM	[0-9]+\.?[0-9]*
 <INITIAL>translate		return TOK_TRANSLATE;
 <INITIAL>z			return TOK_Z;
 
-<INITIAL>gerber			{ BEGIN(FILENAME);
+<INITIAL>gerber			{ file_name_follows = 1;
 				  return TOK_GERBER; }
-<INITIAL>gnuplot		{ BEGIN(FILENAME);
+<INITIAL>gnuplot		{ file_name_follows = 1;
 				  return TOK_GNUPLOT; }
 <INITIAL>write			{ BEGIN(FILENAME);
 				  return TOK_WRITE; }
@@ -60,30 +62,39 @@ NUM	[0-9]+\.?[0-9]*
 <INITIAL>mm			metric = 1;
 <INITIAL>mil			metric = 0;
 
-<INITIAL,FILENAME>{NUM}mm	{ yylval.num = strtod(yytext, NULL);
+<DIGIT>[1-9]			{ BEGIN(INITIAL);
+				  yylval.num = strtod(yytext, NULL);
+				  return REF; }
+
+{NUM}mm				{ yylval.num = strtod(yytext, NULL);
+				  if (file_name_follows)
+					BEGIN(FILENAME);
 				  return NUMBER; }
-<INITIAL,FILENAME>{NUM}mil	{ yylval.num = MIL2MM(strtod(yytext, NULL));
+{NUM}mil			{ yylval.num = MIL2MM(strtod(yytext, NULL));
+				  if (file_name_follows)
+					BEGIN(FILENAME);
 				  return NUMBER; }
-<INITIAL,FILENAME>{NUM}		{ yylval.num = strtod(yytext, NULL);
+{NUM}				{ yylval.num = strtod(yytext, NULL);
 				  if (!metric)
 					yylval.num = MIL2MM(yylval.num);
+				  if (file_name_follows)
+					BEGIN(FILENAME);
 				  return NUMBER; }
 
 <FILENAME>[^ \t\n]+([^\t\n]*[^ \t\n]+)? {
 				  BEGIN(INITIAL);
+				  file_name_follows = 0;
 				  yylval.str = yytext;
 				  return STRING; }
 
-<DIGIT>[1-9]			{ BEGIN(INITIAL);
-				  yylval.num = strtod(yytext, NULL);
-				  return NUMBER; }
-
 [ \t]				;
 \n				lineno++;
 
 ^#\ [0-9]+\ \"[^"]*\"(\ [0-9]+)*\n {
 				  lineno = strtol(yytext+2, NULL, 0); }
 
+<INITIAL>#.*\n			lineno++;
+
 .				return *yytext;
 
 %%

cameo/lang.y

@@ -118,7 +118,7 @@ static void align(int ref, double x, double y)
 %token		TOK_GERBER TOK_GNUPLOT TOK_WRITE
 %token		TOK_DOG
 
-%token	<num>	NUMBER
+%token	<num>	NUMBER REF
 %token	<str>	STRING
 
 %type	<str>	opt_filename
@@ -130,11 +130,11 @@ all:
 	;
 
 command:
-	TOK_ALIGN NUMBER NUMBER NUMBER
+	TOK_ALIGN REF NUMBER NUMBER
 		{
 			align((int) $2, $3, $4);
 		}
-	| TOK_ALIGN NUMBER NUMBER NUMBER NUMBER NUMBER
+	| TOK_ALIGN REF NUMBER NUMBER NUMBER NUMBER
 		{
 			int ref = $2;
 			double x, y;
@@ -179,11 +179,11 @@ command:
 		}
 	| TOK_Z NUMBER
 		{
-			zo -= $2;
+			zo += $2;
 		}
 	| TOK_Z NUMBER NUMBER
 		{
-			zo -= $2+$3;
+			zo += $3-$2;
 		}
 	| TOK_GERBER NUMBER opt_filename
 		{