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Libmarpa can be set up
to generate a
MARPA_EVENT_SYMBOL_PREDICTED
event when a non-nulled symbol is predicted.
A non-nulled symbol is said to be predicted
when a instance of it
is acceptable at the current
earleme according to the grammar.
Nulled symbols do not generate predictions.
For a prediction event to be generated, the symbol must be marked, and the event must be activated.
To mark a symbol as a prediction event symbol
use the marpa_g_symbol_is_prediction_event_set()
method.
The event will be activated by default.
To activate or deactivate a prediction symbol event
use the marpa_r_prediction_symbol_activate()
method.
Allows the user to deactivate and reactivate symbol prediction events in the grammar. On success, does the following:
The activation status of a prediction event in the grammar becomes the initial activation status of a prediction event in all of its child recognizers.
This method is seldom needed.
When a symbol is marked as a prediction event symbol in
the grammar,
it is activated by default.
See marpa_g_symbol_is_prediction_event_set().
And a prediction event can be deactivated
and reactivated in the recognizer
using the
marpa_r_prediction_symbol_activate
method.
See marpa_r_prediction_symbol_activate().
Hard fails if the sym_id is not marked as a prediction event symbol in the grammar, or if the grammar has not been precomputed.
Return value: On success, the value of reactivate, which is a boolean. On hard failure, -2.
Allows the user to deactivate and reactivate symbol prediction events in the recognizer. On success, does the following:
When a recognizer is created, the activation status of its symbol prediction event for sym_id is initialized to the activation status of the symbol prediction event for sym_id in the base grammar.
Hard fails if sym_id was not marked for prediction events in the base grammar.
Return value: On success, the value of reactivate, which is a boolean. On hard failure, -2.
On success, returns a boolean which is 1 iff sym_id is marked as a prediction event symbol in g. For more about prediction events, see marpa_g_symbol_is_prediction_event_set().
On soft failure, sym_id is well-formed, but there is no such symbol.
Hard fails if g is precomputed.
Return value: On success, a boolean . On soft failure, -1. On hard failure, -2.
Libmarpa can be set up
to generate a
MARPA_EVENT_SYMBOL_PREDICTED
event when a non-nulled symbol is predicted.
A non-nulled symbol is said to be predicted
when a instance of it
is acceptable at the current
earleme according to the grammar.
Nulled symbols do not generate predictions.
For prediction events for sym_id to occur, sym_id must be marked as a prediction event symbol, and the prediction event for sym_id must be activated in the recognizer. Event activation also occurs in the grammar, and the recognizer event activation status for sym_id is initialized from the grammar event activation status for sym_id. See marpa_g_prediction_symbol_activate(), and see marpa_r_prediction_symbol_activate().
On success, if value is 1,
On success, if value is 0,
If sym_id is well-formed, but there is no such symbol, soft fails.
Hards fails if the grammar is precomputed.
Return value: On success, value, which is a boolean. On soft failure, -1. On hard failure, -2.
Next: Symbol expected events, Previous: Symbol nulled events, Up: Events [Contents][Index]