package doc

Import Path
	go/doc (on go.dev)

Dependency Relation
	imports 13 packages, and imported by one package


Involved Source Files

	      comment.go
	
		Package doc extracts source code documentation from a Go AST.

	      example.go
	      exports.go
	      filter.go
	      reader.go
	      synopsis.go


Code Examples

	
		package main
		
		import (
			"fmt"
			"go/ast"
			"go/doc"
			"go/parser"
			"go/token"
		)
		
		func main() {
			// src and test are two source files that make up
			// a package whose documentation will be computed.
			const src = `
		// This is the package comment.
		package p
		
		import "fmt"
		
		// This comment is associated with the Greet function.
		func Greet(who string) {
			fmt.Printf("Hello, %s!\n", who)
		}
		`
			const test = `
		package p_test
		
		// This comment is associated with the ExampleGreet_world example.
		func ExampleGreet_world() {
			Greet("world")
		}
		`
		
			// Create the AST by parsing src and test.
			fset := token.NewFileSet()
			files := []*ast.File{
				mustParse(fset, "src.go", src),
				mustParse(fset, "src_test.go", test),
			}
		
			// Compute package documentation with examples.
			p, err := doc.NewFromFiles(fset, files, "example.com/p")
			if err != nil {
				panic(err)
			}
		
			fmt.Printf("package %s - %s", p.Name, p.Doc)
			fmt.Printf("func %s - %s", p.Funcs[0].Name, p.Funcs[0].Doc)
			fmt.Printf(" ⤷ example with suffix %q - %s", p.Funcs[0].Examples[0].Suffix, p.Funcs[0].Examples[0].Doc)
		
		}
		
		func mustParse(fset *token.FileSet, filename, src string) *ast.File {
			f, err := parser.ParseFile(fset, filename, src, parser.ParseComments)
			if err != nil {
				panic(err)
			}
			return f
		}




Package-Level Type Names (total 16, in which 8 are exported)


	/* sort exporteds by:  |  */
	
		An Example represents an example function found in a test source file.

		
			Code ast.Node
			Comments []*ast.CommentGroup
			
				// example function doc string

			
				// expect empty output

			
				// name of the item being exemplified (including optional suffix)

			
				// original source code order

			
				// expected output

			
				// a whole program version of the example

			
				// example suffix, without leading '_' (only populated by NewFromFiles)

			Unordered bool
		
			func Examples(testFiles ...*ast.File) []*Example
		
			


	

		
			func (*Package).Filter(f Filter)
			


	
		Func is the documentation for a func declaration.

		
			Decl *ast.FuncDecl
			Doc string
			
				Examples is a sorted list of examples associated with this
				function or method. Examples are extracted from _test.go files
				provided to NewFromFiles.

			
				// embedding level; 0 means not embedded

			Name string
			
				// original receiver "T" or "*T"

			
				methods
				(for functions, these fields have the respective zero value)
				// actual   receiver "T" or "*T"

		
			
		
			


	
		Mode values control the operation of New and NewFromFiles.

		
			func New(pkg *ast.Package, importPath string, mode Mode) *Package
		
			const AllDecls
			const AllMethods
			const PreserveAST


	
		A Note represents a marked comment starting with "MARKER(uid): note body".
		Any note with a marker of 2 or more upper case [A-Z] letters and a uid of
		at least one character is recognized. The ":" following the uid is optional.
		Notes are collected in the Package.Notes map indexed by the notes marker.

		
			
				// note body text

			
				// position range of the comment containing the marker

			
				// position range of the comment containing the marker

			
				// uid found with the marker

		
			


	
		Package is the documentation for an entire package.

		
			
				Deprecated: For backward compatibility Bugs is still populated,
				but all new code should use Notes instead.

			
				declarations

			Doc string
			
				Examples is a sorted list of examples associated with
				the package. Examples are extracted from _test.go files
				provided to NewFromFiles.

			Filenames []string
			Funcs []*Func
			ImportPath string
			Imports []string
			Name string
			Notes map[string][]*Note
			Types []*Type
			Vars []*Value
		
			
				Filter eliminates documentation for names that don't pass through the filter f.
				TODO(gri): Recognize "Type.Method" as a name.

		
			func New(pkg *ast.Package, importPath string, mode Mode) *Package
			func NewFromFiles(fset *token.FileSet, files []*ast.File, importPath string, opts ...any) (*Package, error)
		
			


	
		Type is the documentation for a type declaration.

		
			
				associated declarations
				// sorted list of constants of (mostly) this type

			Decl *ast.GenDecl
			Doc string
			
				Examples is a sorted list of examples associated with
				this type. Examples are extracted from _test.go files
				provided to NewFromFiles.

			
				// sorted list of functions returning this type

			
				// sorted list of methods (including embedded ones) of this type

			Name string
			
				// sorted list of variables of (mostly) this type

		
			
		
			


	
		Value is the documentation for a (possibly grouped) var or const declaration.

		
			Decl *ast.GenDecl
			Doc string
			
				// var or const names in declaration order

			
		
			
		
			


	


Package-Level Functions (total 56, in which 7 are exported)


	
		Examples returns the examples found in testFiles, sorted by Name field.
		The Order fields record the order in which the examples were encountered.
		The Suffix field is not populated when Examples is called directly, it is
		only populated by NewFromFiles for examples it finds in _test.go files.

		Playable Examples must be in a package whose name ends in "_test".
		An Example is "playable" (the Play field is non-nil) in either of these
		circumstances:
		  - The example function is self-contained: the function references only
		    identifiers from other packages (or predeclared identifiers, such as
		    "int") and the test file does not include a dot import.
		  - The entire test file is the example: the file contains exactly one
		    example function, zero test, fuzz test, or benchmark function, and at
		    least one top-level function, type, variable, or constant declaration
		    other than the example function.


	
		IsPredeclared reports whether s is a predeclared identifier.


	
		New computes the package documentation for the given package AST.
		New takes ownership of the AST pkg and may edit or overwrite it.
		To have the Examples fields populated, use NewFromFiles and include
		the package's _test.go files.


	
		NewFromFiles computes documentation for a package.

		The package is specified by a list of *ast.Files and corresponding
		file set, which must not be nil.
		NewFromFiles uses all provided files when computing documentation,
		so it is the caller's responsibility to provide only the files that
		match the desired build context. "go/build".Context.MatchFile can
		be used for determining whether a file matches a build context with
		the desired GOOS and GOARCH values, and other build constraints.
		The import path of the package is specified by importPath.

		Examples found in _test.go files are associated with the corresponding
		type, function, method, or the package, based on their name.
		If the example has a suffix in its name, it is set in the
		Example.Suffix field. Examples with malformed names are skipped.

		Optionally, a single extra argument of type Mode can be provided to
		control low-level aspects of the documentation extraction behavior.

		NewFromFiles takes ownership of the AST files and may edit them,
		unless the PreserveAST Mode bit is on.


	
		Synopsis returns a cleaned version of the first sentence in s.
		That sentence ends after the first period followed by space and
		not preceded by exactly one uppercase letter. The result string
		has no \n, \r, or \t characters and uses only single spaces between
		words. If s starts with any of the IllegalPrefixes, the result
		is the empty string.


	
		ToHTML converts comment text to formatted HTML.
		The comment was prepared by DocReader,
		so it is known not to have leading, trailing blank lines
		nor to have trailing spaces at the end of lines.
		The comment markers have already been removed.

		Each span of unindented non-blank lines is converted into
		a single paragraph. There is one exception to the rule: a span that
		consists of a single line, is followed by another paragraph span,
		begins with a capital letter, and contains no punctuation
		other than parentheses and commas is formatted as a heading.

		A span of indented lines is converted into a <pre> block,
		with the common indent prefix removed.

		URLs in the comment text are converted into links; if the URL also appears
		in the words map, the link is taken from the map (if the corresponding map
		value is the empty string, the URL is not converted into a link).

		A pair of (consecutive) backticks (`) is converted to a unicode left quote (“), and a pair of (consecutive)
		single quotes (') is converted to a unicode right quote (”).

		Go identifiers that appear in the words map are italicized; if the corresponding
		map value is not the empty string, it is considered a URL and the word is converted
		into a link.


	
		ToText prepares comment text for presentation in textual output.
		It wraps paragraphs of text to width or fewer Unicode code points
		and then prefixes each line with the indent. In preformatted sections
		(such as program text), it prefixes each non-blank line with preIndent.

		A pair of (consecutive) backticks (`) is converted to a unicode left quote (“), and a pair of (consecutive)
		single quotes (') is converted to a unicode right quote (”).


	



Package-Level Constants (total 16, in which 3 are exported)


	
		AllDecls says to extract documentation for all package-level
		declarations, not just exported ones.


	
		AllMethods says to show all embedded methods, not just the ones of
		invisible (unexported) anonymous fields.


	
		PreserveAST says to leave the AST unmodified. Originally, pieces of
		the AST such as function bodies were nil-ed out to save memory in
		godoc, but not all programs want that behavior.