1 files changed, 116 insertions, 0 deletions
diff --git a/examples/statechart.rl b/examples/statechart.rl
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+++ b/examples/statechart.rl
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+/*
+ * Demonstrate the use of labels, the epsilon operator, and the join operator
+ * for creating machines using the named state and transition list paradigm.
+ * This implementes the same machine as the atoi example.
+ */
+
+#include <iostream>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+using namespace std;
+
+struct StateChart
+{
+	bool neg;
+	int val;
+	int cs;
+
+	int init( );
+	int execute( const char *data, int len );
+	int finish( );
+};
+
+%%{
+	machine StateChart;
+
+	action begin {
+		neg = false;
+		val = 0;
+	}
+
+	action see_neg {
+		neg = true;
+	}
+
+	action add_digit { 
+		val = val * 10 + (fc - '0');
+	}
+
+	action finish {
+		if ( neg )
+			val = -1 * val;
+	}
+
+	atoi = (
+		start: (
+			'-' @see_neg ->om_num | 
+			'+' ->om_num |
+			[0-9] @add_digit ->more_nums
+		),
+
+		# One or more nums.
+		om_num: (
+			[0-9] @add_digit ->more_nums
+		),
+
+		# Zero ore more nums.
+		more_nums: (
+			[0-9] @add_digit ->more_nums |
+			'' -> final
+		)
+	) >begin %finish;
+
+	main := ( atoi '\n' @{ cout << val << endl; } )*;
+}%%
+
+%% write data;
+
+int StateChart::init( )
+{
+	neg = false;
+	val = false;
+	%% write init;
+	return 1;
+}
+
+int StateChart::execute( const char *data, int len )
+{
+	const char *p = data;
+	const char *pe = data + len;
+
+	%% write exec;
+
+	if ( cs == StateChart_error )
+		return -1;
+	if ( cs >= StateChart_first_final )
+		return 1;
+	return 0;
+}
+
+int StateChart::finish( )
+{
+	if ( cs == StateChart_error )
+		return -1;
+	if ( cs >= StateChart_first_final )
+		return 1;
+	return 0;
+}
+
+
+#define BUFSIZE 1024
+
+int main()
+{
+	char buf[BUFSIZE];
+
+	StateChart atoi;
+	atoi.init();
+	while ( fgets( buf, sizeof(buf), stdin ) != 0 ) {
+		atoi.execute( buf, strlen(buf) );
+	}
+	if ( atoi.finish() <= 0 )
+		cerr << "statechart: error: parsing input" << endl;
+	return 0;
+}