func (a *assembler) buildBlockOperand(argv *[]cpu.Word, symbols *[]parser.Node, node parser.Node) (cpu.Word, error) {
switch tt := node.(type) {
case *parser.Name:
if reg, ok := registers[tt.Data]; ok {
if reg <= 0x7 {
return reg + 0x10, nil
}
if reg == 0x1b {
return 0x1a, nil
}
return 0, NewBuildError(
a.ast.Files[tt.File()], tt.Line(), tt.Col(),
"Illegal use of register %q.", tt.Data,
)
}
if addr, ok := a.labels[tt.Data]; ok {
*symbols = append(*symbols, tt)
*argv = append(*argv, addr)
return 0, nil
}
a.refs[cpu.Word(len(a.code)+1+len(*argv))] = tt
*symbols = append(*symbols, tt)
*argv = append(*argv, 0)
return 0, nil
case parser.NumericNode:
num, err := tt.Parse()
if err != nil {
return 0, err
}
*symbols = append(*symbols, tt)
*argv = append(*argv, num)
return 0, nil
}
return 0, NewBuildError(
a.ast.Files[node.File()], node.Line(), node.Col(),
"Unexpected node %T. Want Name or Number.", node,
)
}
