func close(c chan<- Type)

// The panic built-in function stops normal execution of the current
// goroutine. When a function F calls panic, normal execution of F stops
// immediately. Any functions whose execution was deferred by F are run in
// the usual way, and then F returns to its caller. To the caller G, the
// invocation of F then behaves like a call to panic, terminating G's

The [GODEBUG History](#history) gives the exact defaults for each Go toolchain version.
For example, Go 1.21 introduces the `panicnil` setting,
controlling whether `panic(nil)` is allowed;
it defaults to `panicnil=0`, making `panic(nil)` a run-time error.
Using `panicnil=1` restores the behavior of Go 1.20 and earlier.

When compiling a work module or workspace that declares

package main

import (
	"go/ast"
	"go/token"
)

func (f *File) walkUnexpected(x interface{}, context astContext, visit func(*File, interface{}, astContext)) {
	error_(token.NoPos, "unexpected type %T in walk", x)
	panic("unexpected type")
}

func funcTypeTypeParams(n *ast.FuncType) *ast.FieldList {
	return nil
}

func typeSpecTypeParams(n *ast.TypeSpec) *ast.FieldList {
	return nil

// Exported for testing only.
import (
	"unicode/utf8"
)

var IsSpace = isSpace

const DefaultBufSize = defaultBufSize

func (s *Scanner) MaxTokenSize(n int) {
	if n < utf8.UTFMax || n > 1e9 {
		panic("bad max token size")
	}
	if n < len(s.buf) {
		s.buf = make([]byte, n)
	}
	s.maxTokenSize = n
}

// ErrOrEOF is like Err, but returns EOF. Used to test a corner case.
func (s *Scanner) ErrOrEOF() error {

func TestDontLoopForever(t *testing.T) {
	s := NewScanner(strings.NewReader("abc"))
	s.Split(loopAtEOFSplit)
	// Expect a panic
	defer func() {
		err := recover()
		if err == nil {
			t.Fatal("should have panicked")
		}
		if msg, ok := err.(string); !ok || !strings.Contains(msg, "empty tokens") {
			panic(err)
		}
	}()
	for count := 0; s.Scan(); count++ {
		if count > 1000 {
			t.Fatal("looping")
		}
	}

<component name="DependencyValidationManager">
    <!-- The source of truth for this pattern is `build-logic/basics/src/main/kotlin/gradlebuild/basics/PublicApi.kt` file, please keep them in sync -->
    <scope name="Gradle public API"

	b, err := hex.DecodeString(s)
	if err != nil {
		panic(err)
	}
	return b
}

func returnBigZipBytes() (r io.ReaderAt, size int64) {
	b := biggestZipBytes()
	for i := 0; i < 2; i++ {
		r, err := NewReader(bytes.NewReader(b), int64(len(b)))
		if err != nil {
			panic(err)
		}
		f, err := r.File[0].Open()
		if err != nil {
			panic(err)
		}
		b, err = io.ReadAll(f)

		copy(b.toSTAR().trailer(), trailerSTAR)
	case format.has(FormatUSTAR | FormatPAX):
		copy(b.toUSTAR().magic(), magicUSTAR)
		copy(b.toUSTAR().version(), versionUSTAR)
	default:
		panic("invalid format")
	}

	// Update checksum.
	// This field is special in that it is terminated by a NULL then space.
	var f formatter
	field := b.toV7().chksum()

	if _, dup := decompressors.LoadOrStore(method, dcomp); dup {
		panic("decompressor already registered")
	}
}

// RegisterCompressor registers custom compressors for a specified method ID.
// The common methods [Store] and [Deflate] are built in.
func RegisterCompressor(method uint16, comp Compressor) {
	if _, dup := compressors.LoadOrStore(method, comp); dup {
		panic("compressor already registered")
	}
}

func TestNegativeRead(t *testing.T) {
	// should panic with a description pointing at the reader, not at itself.
	// (should NOT panic with slice index error, for example.)
	b := NewReader(new(negativeReader))
	defer func() {
		switch err := recover().(type) {
		case nil:
			t.Fatal("read did not panic")
		case error: