wr Instruction ¶This instruction has the syntaxes
wr TERM_IDX
wr TERM_IDX, ORD
The instruction prepends a PCFG terminal symbol with index TERM_IDX to the beginning of a training terminal symbol sequence.
A subsequent instruction peek (see peek Instruction), rd (see rd Instruction), or scn (see scn Instruction) will read the prepended terminal symbol.
If a series of wr instructions outputs multiple terminal symbols, subsequent peek, rd, and scn instructions will read the terminal symbols in reverse order.
The optional parameter ORD specifies the ordinal number of a wr instruction that outputs a particular terminal symbol.
Ordinal numbers make it possible to distinguish occurrences of wr instructions that output the same terminal symbol.