Add support for parsing of REF_TO keyword (defined in IEC61131-3 v3). This support is currently inactive (in flex) until we get to add C code generation later on.
PROGRAM foo
VAR_INPUT
single, interval, priority : BOOL;
END_VAR
LD single
LD interval
LD priority
END_PROGRAM
PROGRAM priority
VAR_INPUT
bar : BOOL;
END_VAR
LD bar
END_PROGRAM
PROGRAM single
VAR_INPUT
bar : BOOL;
END_VAR
LD bar
END_PROGRAM
PROGRAM interval
VAR_INPUT
bar : BOOL;
END_VAR
LD bar
END_PROGRAM
CONFIGURATION config1
TASK fast(PRIORITY := 4);
PROGRAM P1 WITH fast:
FOO(single := TRUE, interval := TRUE, priority := TRUE);
END_CONFIGURATION
CONFIGURATION config2
TASK fast(SINGLE := 3, PRIORITY := 4);
PROGRAM P1 WITH fast:
FOO(single := TRUE, interval := TRUE, priority := TRUE);
END_CONFIGURATION
CONFIGURATION config3
TASK fast(INTERVAL := T#1s, PRIORITY := 4);
PROGRAM P1 WITH fast:
FOO(single := TRUE, interval := TRUE, priority := TRUE);
END_CONFIGURATION
CONFIGURATION config4
TASK fast(SINGLE := 3, INTERVAL := T#1s, PRIORITY := 4);
PROGRAM P1 WITH fast:
FOO(single := TRUE, interval := TRUE, priority := TRUE);
END_CONFIGURATION