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rd Instruction

This instruction has a short and long form:

        rd      LENGTH
        rd      NONT_QUOTED, RHS, POS, LENGTH

The option --dump-asm[=simple] dumps an assembler program with rd instructions in the short form. The option --dump-asm=extended dumps an assembler program with rd instructions in the long form. The program topdown uses rd instructions in the long form.

The instruction consumes LENGTH symbols from a training terminal symbol sequence—increments the current position in the training sequence by LENGTH.

Optionally, the instruction increments the frequency of a production with an auxiliary nonterminal symbol _X_iT or _X_iTj at the left-hand side and a consumed terminal symbol sequence at the right-hand side and updates the spur accordingly. The parameters NONT_QUOTED, RHS, and POS identify this auxiliary nonterminal symbol in the right-hand side of a production of a context-free grammar for a regular expression.

The parameter NONT_QUOTED is a nonterminal symbol specified in double quotation marks and located at the left-hand side of a production that contains the auxiliary nonterminal symbol. The parameter RHS is the index of a right-hand side containing the auxiliary nonterminal symbol. The parameter POS is the position of this auxiliary nonterminal symbol in the right-hand side.

Example:

        rd      "E", 2, 3, 4

This instruction consumes a sequence of four terminal symbols from a training terminal symbol sequence. Additionally, the instruction increments the frequency of a production for an auxiliary nonterminal symbol at the left-hand side and the consumed terminal symbol sequence at the right-hand side. The occurrence of this auxiliary nonterminal symbol is at zero-based position 3 in a right-hand side at zero-based index 2 for the nonterminal symbol E at the left-hand side. For example, this auxiliary nonterminal symbol could be the symbol _E_2T4 in the following excerpt of a context-free grammar:

E: A
 | B
 | _E_1T C C _E_2T4 D
;

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