NAME

CPU::Z80::Assembler::Opcode - Represents one assembly expression to be computed at link time

SYNOPSIS

  use CPU::Z80::Assembler::Opcode;
  $opcode = CPU::Z80::Assembler::Opcode->new(
                                        address => 0,
                                        line => $line,
                                        child => [byte, byte, ["type", $expr]]);
  $value = $opcode->evaluate;
  $bytes = $opcode->bytes($address, \%symbol_table);
  $size = $opcode->size;

DESCRIPTION

This module defines the class that represents one assembly instruction to be added to the object code. The instruction can contain references to CPU::Z80::Assembler::Expr expressions that are computed at link time.

EXPORTS

Nothing.

FUNCTIONS

new

Creates a new object.

address

Address where this opcode is loaded, computed at link time.

child

The number of children is the number of bytes stored in the object code for this instruction.

Each child is either a scalar containing the byte value to be added to the object code, or a CPU::Z80::Assembler::Expr expression to be evaluated at link time. In case of a word expression, then a special undef value is used as a placeholder to keep the "child" list the correct size.

line

Get/set the line - text, file name and line number where the token was read.

evaluate

Called when opcode is referred to by a label, returns the opcode address.

bytes

  $bytes = $opcode->bytes($address, \%symbol_table);

Computes all the expressions in "child" and returns the bytes string with the result object code.

size

  $size = $opcode->size;

Return the number of bytes that this opcode will generate.

BUGS and FEEDBACK

See CPU::Z80::Assembler.

AUTHORS, COPYRIGHT and LICENCE

See CPU::Z80::Assembler.