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<p class=MsoNormal>Dear All,<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>I have a question about the time of execution of the actions
put inside or at the end of the rules. I can see from the generated lexer or
parser code that the actions (at the end of the rule) are inserted after the
match of the whole rule. But I would like to know if any actions (in the middle
or at the end) would be executed before the match of the rule? i.e. at the Look
Ahead (Prediction) stage, would the match of a part of the rule trigger any
actions of the subrule matched? <o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>For example:<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Rule : Rule1| Rule2;<o:p></o:p></p>
<p class=MsoNormal>Rule1 : Rule3* Rule4;<o:p></o:p></p>
<p class=MsoNormal>Rule2 : ( Rule3 Rule3 )* Rule5;<o:p></o:p></p>
<p class=MsoNormal>Rule3 : AnyRule { AnyAction; };<o:p></o:p></p>
<p class=MsoNormal>Rule4 : xxx;<o:p></o:p></p>
<p class=MsoNormal>Rule5 : yyy;<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>When trying to find out if the input matches Rule1 or Rule2,
will the AnyAction be executed? Or if the action is in the middle of the rule,
will it be executed before the match of the full rule?<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>I haven’t found out any theoretical confirmation from the
book, so would like to ask if anybody can confirm how it works.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Thanks.<o:p></o:p></p>
<p class=MsoNormal>Linlin<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
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