popdwr Instruction ¶This instruction has the syntax
popdwr NUM
The instruction pops NUM terminal symbols from the stack of deferred terminal symbols and prepends every popped terminal symbol to the beginning of a training terminal symbol sequence, as the wr instruction (see wr Instruction) does.
The added terminal symbols become available for fetching by the rd and scn instructions (see rd Instruction and scn Instruction) in the order of pushing the terminal symbols to the stack of deferred terminal symbols by the pushd instructions (see pushd Instruction).
Example:
popdwr 5
This instruction pops five terminal symbols from the stack of deferred terminal symbols and prepends the popped terminal symbols to the beginning of a training terminal symbol sequence.
An rd instruction following the popdwr instruction will read the prepended terminal symbols.