### New unique package

The new [unique](/pkg/unique) package provides facilities for
canonicalizing values (like "interning" or "hash-consing").

Any value of comparable type may be canonicalized with the new
`Make[T]` function, which produces a reference to a canonical copy of
the value in the form of a `Handle[T]`.
Two `Handle[T]` are equal if and only if the values used to produce the
handles are equal, allowing programs to deduplicate values and reduce

//
//	slice = append(slice, elem1, elem2)
//	slice = append(slice, anotherSlice...)
//
// As a special case, it is legal to append a string to a byte slice, like this:
//
//	slice = append([]byte("hello "), "world"...)
func append(slice []Type, elems ...Type) []Type

// The copy built-in function copies elements from a source slice into a

// io.ByteScanner, and io.RuneScanner interfaces by reading from
// a byte slice.
// Unlike a [Buffer], a Reader is read-only and supports seeking.
// The zero value for Reader operates like a Reader of an empty slice.
type Reader struct {
	s        []byte
	i        int64 // current reading index
	prevRune int   // index of previous rune; or < 0
}

func (p *Parser) operand(a *obj.Addr) {
	//fmt.Printf("Operand: %v\n", p.input)
	if len(p.input) == 0 {
		p.errorf("empty operand: cannot happen")
		return
	}
	// General address (with a few exceptions) looks like
	//	$sym±offset(SB)(reg)(index*scale)
	// Exceptions are:
	//
	//	R1
	//	offset
	//	$offset
	// Every piece is optional, so we scan left to right and what
	// we discover tells us where we are.

	if panicOnError {
		panic(fmt.Errorf("%s:%d: %s", in.File(), in.Line(), fmt.Sprintln(args...)))
	}
	fmt.Fprintf(os.Stderr, "%s:%d: %s", in.File(), in.Line(), fmt.Sprintln(args...))
	os.Exit(1)
}

// expectText is like Error but adds "got XXX" where XXX is a quoted representation of the most recent token.
func (in *Input) expectText(args ...interface{}) {
	in.Error(append(args, "; got", strconv.Quote(in.Stack.Text()))...)
}

</p>

<pre>
f := t.Mv; f(7)   // like t.Mv(7)
f := pt.Mp; f(7)  // like pt.Mp(7)
f := pt.Mv; f(7)  // like (*pt).Mv(7)
f := t.Mp; f(7)   // like (&amp;t).Mp(7)
f := makeT().Mp   // invalid: result of makeT() is not addressable
</pre>

<p>

}

// Write writes to the current file in the tar archive.
// Write returns the error [ErrWriteTooLong] if more than
// Header.Size bytes are written after [Writer.WriteHeader].
//
// Calling Write on special types like [TypeLink], [TypeSymlink], [TypeChar],
// [TypeBlock], [TypeDir], and [TypeFifo] returns (0, [ErrWriteTooLong]) regardless
// of what the [Header.Size] claims.
func (tw *Writer) Write(b []byte) (int, error) {

		t.Errorf("Modified: got %s, want %s\n", got, want)
	}
}

type repeatedByte struct {
	off int64
	b   byte
	n   int64
}

// rleBuffer is a run-length-encoded byte buffer.
// It's an io.Writer (like a bytes.Buffer) and also an io.ReaderAt,
// allowing random-access reads.
type rleBuffer struct {
	buf []repeatedByte
}

func (r *rleBuffer) Size() int64 {
	if len(r.buf) == 0 {
		return 0
	}

}

// The other files in this directory each contain an implementation of TokenReader.

// A TokenReader is like a reader, but returns lex tokens of type Token. It also can tell you what
// the text of the most recently returned token is, and where it was found.
// The underlying scanner elides all spaces except newline, so the input looks like a stream of
// Tokens; original spacing is lost but we don't need it.
type TokenReader interface {

				//   BC 4,...
				// into
				//   BC $4,...
				prog.From = obj.Addr{
					Type:   obj.TYPE_CONST,
					Offset: p.getConstant(prog, op, &a[0]),
				}

			}

			// Likewise, fixup usage like:
			//   BC x,LT,...
			//   BC x,foo+2,...
			//   BC x,4
			//   BC x,$5
			// into
			//   BC x,CR0LT,...
			//   BC x,CR0EQ,...
			//   BC x,CR1LT,...
			//   BC x,CR1GT,...