// buildBlock builds a block expression.
func (a *assembler) buildBlock(argv *[]cpu.Word, symbols *[]parser.Node, b *parser.Block) (val cpu.Word, err error) {
nodes := b.Children()
switch len(nodes) {
case 1:
switch tt := nodes[0].(type) {
case *parser.Name:
if reg, ok := registers[tt.Data]; ok {
return reg + 0x08, nil
}
if addr, ok := a.labels[tt.Data]; ok {
*symbols = append(*symbols, tt)
*argv = append(*argv, addr)
return 0x1e, nil
}
a.refs[cpu.Word(len(a.code)+1+len(*argv))] = tt
*symbols = append(*symbols, tt)
*argv = append(*argv, 0)
return 0x1e, nil
case parser.NumericNode:
num, err := tt.Parse()
if err != nil {
return 0, err
}
*symbols = append(*symbols, tt)
*argv = append(*argv, num)
return 0x1e, nil
default:
return 0, NewBuildError(
a.ast.Files[tt.File()], tt.Line(), tt.Col(),
"Unexpected node %T. Want Name, Number or Block.", tt,
)
}
case 3:
var va, vb cpu.Word
if va, err = a.buildBlockOperand(argv, symbols, nodes[0]); err != nil {
return
}
if vb, err = a.buildBlockOperand(argv, symbols, nodes[2]); err != nil {
return
}
if va != 0 {
return va, nil
}
return vb, nil
default:
err = NewBuildError(
a.ast.Files[b.File()], b.Line(), b.Col(),
"Unexpected node count. Want 1 or 3. Got %d", len(nodes))
}
return
}
func (sw *SourceWriter) writeBlock(n *parser.Block) {
sw.w.Write(lbrack)
sw.writeList(n.Children())
sw.w.Write(rbrack)
}
