- YYPACT[S] = index in YYTABLE of the portion describing state S.
- The lookahead token's type is used to index that portion to find
- out what to do.
-
- If the value in YYTABLE is positive, we shift the token and go to
- that state.
-
- If the value is negative, it is minus a rule number to reduce by.
-
- If the value is zero, the default action from YYDEFACT[S] is used.
-
- YYPGOTO[I] = the index in YYTABLE of the portion describing what to
- do after reducing a rule that derives variable I + NTOKENS. This
- portion is indexed by the parser state number, S, as of before the
- text for this nonterminal was read. The value from YYTABLE is the
- state to go to if the corresponding value in YYCHECK is S.
-
- YYTABLE = a vector filled with portions for different uses, found
- via YYPACT and YYPGOTO.
-
- YYCHECK = a vector indexed in parallel with YYTABLE. It indicates,
- in a roundabout way, the bounds of the portion you are trying to
- examine.
-
- Suppose that the portion of YYTABLE starts at index P and the index
- to be examined within the portion is I. Then if YYCHECK[P+I] != I,
- I is outside the bounds of what is actually allocated, and the
- default (from YYDEFACT or YYDEFGOTO) should be used. Otherwise,
- YYTABLE[P+I] should be used.