1 files changed, 53 insertions, 0 deletions
diff --git a/examples/hello_calc2/parser.y b/examples/hello_calc2/parser.y
new file mode 100644
index 0000000..67bef50
--- /dev/null
+++ b/examples/hello_calc2/parser.y
@@ -0,0 +1,53 @@
+
+%{
+#include <stdio.h>
+#include <math.h>
+%}
+
+%union {
+	double value;
+	char* name;
+}
+
+%token <value> NUMBER
+
+%type  <value>  expr
+
+%left '+' '-'
+%right SQRT
+%left '*' '/'
+%right '^'
+%right UMINUS
+
+%%
+lines:	lines expr '\n'		{ printf("%.10g\n", $2); }
+	|	lines '\n'
+	|	error '\n' 		{ printf("Please re-enter last line: ");
+	                	  yyerrok; }
+	|
+	;
+
+expr:	expr '+' expr	{ $$ = $1 + $3; }
+	|	expr '-' expr	{ $$ = $1 - $3; }
+	|	expr '*' expr	{ $$ = $1 * $3; }
+	|	expr '/' expr	{ $$ = $1 / $3; }
+	|	expr '^' expr	{ $$ = pow($1, $3); }
+	|	'(' expr ')'	{ $$ = $2; }
+	|	'-' expr  %prec UMINUS { $$ = -$2; }
+	|	NUMBER
+	;
+
+%%
+#include <ctype.h>
+#include <stdio.h>
+
+int main (int argc, char **argv)
+{
+	return yyparse ();
+}
+
+int yyerror (char* errstr)
+{
+	printf ("Error: %s\n", errstr);
+	return 1;
+}