ragel-6.9ragel-6.9

1 files changed, 96 insertions, 0 deletions

diff --git a/examples/gotocallret.rl b/examples/gotocallret.rl
new file mode 100644
index 0000000..32c01a2
--- /dev/null
+++ b/examples/gotocallret.rl
@@ -0,0 +1,96 @@
+/*
+ * Demonstrate the use of goto, call and return. This machine expects either a
+ * lower case char or a digit as a command then a space followed by the command
+ * arg. If the command is a char, then the arg must be an a string of chars.
+ * If the command is a digit, then the arg must be a string of digits. This
+ * choice is determined by action code, rather than though transition
+ * desitinations.
+ */
+
+#include <iostream>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+using namespace std;
+
+struct GotoCallRet 
+{
+	char comm;
+	int cs, top, stack[32];
+
+	int init( );
+	int execute( const char *data, int len, bool isEof );
+	int finish( );
+};
+
+%%{
+	machine GotoCallRet;
+
+	# Error machine, consumes to end of 
+	# line, then starts the main line over.
+	garble_line := (
+		(any-'\n')*'\n'
+	) >{cout << "error: garbling line" << endl;} @{fgoto main;};
+
+	# Look for a string of alphas or of digits, 
+	# on anything else, hold the character and return.
+	alp_comm := alpha+ $!{fhold;fret;};
+	dig_comm := digit+ $!{fhold;fret;};
+
+	# Choose which to machine to call into based on the command.
+	action comm_arg {
+		if ( comm >= 'a' )
+			fcall alp_comm;
+		else 
+			fcall dig_comm;
+	}
+
+	# Specifies command string. Note that the arg is left out.
+	command = (
+		[a-z0-9] @{comm = fc;} ' ' @comm_arg '\n'
+	) @{cout << "correct command" << endl;};
+
+	# Any number of commands. If there is an 
+	# error anywhere, garble the line.
+	main := command* $!{fhold;fgoto garble_line;};
+}%%
+
+%% write data;
+
+int GotoCallRet::init( )
+{
+	%% write init;
+	return 1;
+}
+
+int GotoCallRet::execute( const char *data, int len, bool isEof )
+{
+	const char *p = data;
+	const char *pe = data + len;
+	const char *eof = isEof ? pe : 0;
+
+	%% write exec;
+	if ( cs == GotoCallRet_error )
+		return -1;
+	if ( cs >= GotoCallRet_first_final )
+		return 1;
+	return 0;
+}
+
+#define BUFSIZE 1024
+
+int main()
+{
+	char buf[BUFSIZE];
+
+	GotoCallRet gcr;
+	gcr.init();
+	while ( fgets( buf, sizeof(buf), stdin ) != 0 )
+		gcr.execute( buf, strlen(buf), false );
+
+	gcr.execute( 0, 0, true );
+	if ( gcr.cs < GotoCallRet_first_final )
+		cerr << "gotocallret: error: parsing input" << endl;
+	return 0;
+}