go doc cmd/doc
		Show package docs for the doc command.
	go doc -cmd cmd/doc
		Show package docs and exported symbols within the doc command.
	go doc template.new
		Show documentation for html/template's New function.
		(html/template is lexically before text/template)
	go doc text/template.new # One argument
		Show documentation for text/template's New function.
	go doc text/template new # Two arguments

use a [Parser]:

	var p comment.Parser
	doc := p.Parse(text)

The result is a [*Doc].
To reformat it as a doc comment, HTML, Markdown, or plain text,
use a [Printer]:

	var pr comment.Printer
	os.Stdout.Write(pr.Text(doc))

The [Parser] and [Printer] types are structs whose fields can be
modified to customize the operations.
For details, see the documentation for those types.

package p

/*
Doc comment.
  - List1.

  - List2.
*/
var X int

/* erroneous doc comment */
var Y int

/*
 * Another erroneous
 * doc comment.
 */

package p

/*
Doc comment.

  - List1.

  - List2.
*/
var X int

/* erroneous doc comment */
var Y int

/*
 * Another erroneous
 * doc comment.
 */

// license that can be found in the LICENSE file.

// Package doc extracts source code documentation from a Go AST.
package doc

import (
	"fmt"
	"go/ast"
	"go/doc/comment"
	"go/token"
	"strings"
)

// Package is the documentation for an entire package.
type Package struct {
	Doc        string
	Name       string
	ImportPath string
	Imports    []string
	Filenames  []string

# go doc --help
! go doc --help
stderr 'go doc'
stderr 'go doc <pkg>'
stderr 'go doc <sym>\[\.<methodOrField>\]'
stderr 'go doc \[<pkg>\.\]<sym>\[\.<methodOrField>\]'
stderr 'go doc \[<pkg>\.\]\[<sym>\.\]<methodOrField>'
stderr 'go doc <pkg> <sym>\[\.<methodOrField>\]'

# go help doc
go help doc
stdout 'go doc'
stdout 'go doc <pkg>'
stdout 'go doc <sym>\[\.<methodOrField>\]'
stdout 'go doc \[<pkg>\.\]<sym>\[\.<methodOrField>\]'

// license that can be found in the LICENSE file.

// Package race implements data race detection logic.
// No public interface is provided.
// For details about the race detector see
// https://golang.org/doc/articles/race_detector.html
package race

the main variation having to do with addressing modes. Input is
run through a simplified C preprocessor that implements #include,
#define, #ifdef/endif, but not #if or ##.

For more information, see https://golang.org/doc/asm.
*/

		which may be set by the -extld option.
		Set to "none" to use no support library.
	-linkmode mode
		Set link mode (internal, external, auto).
		This sets the linking mode as described in cmd/cgo/doc.go.
	-linkshared
		Link against installed Go shared libraries (experimental).
	-memprofile file
		Write memory profile to file.
	-memprofilerate rate
		Set runtime.MemProfileRate to rate.
	-msan

// statements that might render the reference benign.
// ("Last statement" is defined recursively in compound
// statements such as if, switch, and select.)
//
// See: https://golang.org/doc/go_faq.html#closures_and_goroutines