// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package main
import (
"bytes"
"fmt"
"go/ast"
"go/build"
"go/doc"
"go/format"
"go/parser"
"go/token"
"io"
"log"
"os"
"path/filepath"
"strings"
"unicode"
"unicode/utf8"
)
const (
punchedCardWidth = 80 // These things just won't leave us alone.
indentedWidth = punchedCardWidth - len(indent)
indent = " "
)
type Package struct {
writer io.Writer // Destination for output.
name string // Package name, json for encoding/json.
userPath string // String the user used to find this package.
pkg *ast.Package // Parsed package.
file *ast.File // Merged from all files in the package
doc *doc.Package
build *build.Package
fs *token.FileSet // Needed for printing.
buf bytes.Buffer
}
type PackageError string // type returned by pkg.Fatalf.
func (p PackageError) Error() string {
return string(p)
}
// prettyPath returns a version of the package path that is suitable for an
// error message. It obeys the import comment if present. Also, since
// pkg.build.ImportPath is sometimes the unhelpful "" or ".", it looks for a
// directory name in GOROOT or GOPATH if that happens.
func (pkg *Package) prettyPath() string {
path := pkg.build.ImportComment
if path == "" {
path = pkg.build.ImportPath
}
if path != "." && path != "" {
return path
}
// Convert the source directory into a more useful path.
// Also convert everything to slash-separated paths for uniform handling.
path = filepath.Clean(filepath.ToSlash(pkg.build.Dir))
// Can we find a decent prefix?
goroot := filepath.Join(build.Default.GOROOT, "src")
if p, ok := trim(path, filepath.ToSlash(goroot)); ok {
return p
}
for _, gopath := range splitGopath() {
if p, ok := trim(path, filepath.ToSlash(gopath)); ok {
return p
}
}
return path
}
// trim trims the directory prefix from the path, paying attention
// to the path separator. If they are the same string or the prefix
// is not present the original is returned. The boolean reports whether
// the prefix is present. That path and prefix have slashes for separators.
func trim(path, prefix string) (string, bool) {
if !strings.HasPrefix(path, prefix) {
return path, false
}
if path == prefix {
return path, true
}
if path[len(prefix)] == '/' {
return path[len(prefix)+1:], true
}
return path, false // Textual prefix but not a path prefix.
}
// pkg.Fatalf is like log.Fatalf, but panics so it can be recovered in the
// main do function, so it doesn't cause an exit. Allows testing to work
// without running a subprocess. The log prefix will be added when
// logged in main; it is not added here.
func (pkg *Package) Fatalf(format string, args ...interface{}) {
panic(PackageError(fmt.Sprintf(format, args...)))
}
// parsePackage turns the build package we found into a parsed package
// we can then use to generate documentation.
func parsePackage(writer io.Writer, pkg *build.Package, userPath string) *Package {
fs := token.NewFileSet()
// include tells parser.ParseDir which files to include.
// That means the file must be in the build package's GoFiles or CgoFiles
// list only (no tag-ignored files, tests, swig or other non-Go files).
include := func(info os.FileInfo) bool {
for _, name := range pkg.GoFiles {
if name == info.Name() {
return true
}
}
for _, name := range pkg.CgoFiles {
if name == info.Name() {
return true
}
}
return false
}
pkgs, err := parser.ParseDir(fs, pkg.Dir, include, parser.ParseComments)
if err != nil {
log.Fatal(err)
}
// Make sure they are all in one package.
if len(pkgs) != 1 {
log.Fatalf("multiple packages in directory %s", pkg.Dir)
}
astPkg := pkgs[pkg.Name]
// TODO: go/doc does not include typed constants in the constants
// list, which is what we want. For instance, time.Sunday is of type
// time.Weekday, so it is defined in the type but not in the
// Consts list for the package. This prevents
// go doc time.Sunday
// from finding the symbol. Work around this for now, but we
// should fix it in go/doc.
// A similar story applies to factory functions.
docPkg := doc.New(astPkg, pkg.ImportPath, doc.AllDecls)
for _, typ := range docPkg.Types {
docPkg.Consts = append(docPkg.Consts, typ.Consts...)
docPkg.Vars = append(docPkg.Vars, typ.Vars...)
docPkg.Funcs = append(docPkg.Funcs, typ.Funcs...)
}
return &Package{
writer: writer,
name: pkg.Name,
userPath: userPath,
pkg: astPkg,
file: ast.MergePackageFiles(astPkg, 0),
doc: docPkg,
build: pkg,
fs: fs,
}
}
func (pkg *Package) Printf(format string, args ...interface{}) {
fmt.Fprintf(&pkg.buf, format, args...)
}
func (pkg *Package) flush() {
_, err := pkg.writer.Write(pkg.buf.Bytes())
if err != nil {
log.Fatal(err)
}
pkg.buf.Reset() // Not needed, but it's a flush.
}
var newlineBytes = []byte("\n\n") // We never ask for more than 2.
// newlines guarantees there are n newlines at the end of the buffer.
func (pkg *Package) newlines(n int) {
for !bytes.HasSuffix(pkg.buf.Bytes(), newlineBytes[:n]) {
pkg.buf.WriteRune('\n')
}
}
// emit prints the node.
func (pkg *Package) emit(comment string, node ast.Node) {
if node != nil {
err := format.Node(&pkg.buf, pkg.fs, node)
if err != nil {
log.Fatal(err)
}
if comment != "" {
pkg.newlines(1)
doc.ToText(&pkg.buf, comment, " ", indent, indentedWidth)
pkg.newlines(2) // Blank line after comment to separate from next item.
} else {
pkg.newlines(1)
}
}
}
// oneLineNode returns a one-line summary of the given input node.
func (pkg *Package) oneLineNode(node ast.Node) string {
const maxDepth = 10
return pkg.oneLineNodeDepth(node, maxDepth)
}
// oneLineNodeDepth returns a one-line summary of the given input node.
// The depth specifies the maximum depth when traversing the AST.
func (pkg *Package) oneLineNodeDepth(node ast.Node, depth int) string {
const dotDotDot = "..."
if depth == 0 {
return dotDotDot
}
depth--
switch n := node.(type) {
case nil:
return ""
case *ast.GenDecl:
// Formats const and var declarations.
trailer := ""
if len(n.Specs) > 1 {
trailer = " " + dotDotDot
}
// Find the first relevant spec.
typ := ""
for i, spec := range n.Specs {
valueSpec := spec.(*ast.ValueSpec) // Must succeed; we can't mix types in one GenDecl.
// The type name may carry over from a previous specification in the
// case of constants and iota.
if valueSpec.Type != nil {
typ = fmt.Sprintf(" %s", pkg.oneLineNodeDepth(valueSpec.Type, depth))
} else if len(valueSpec.Values) > 0 {
typ = ""
}
if !isExported(valueSpec.Names[0].Name) {
continue
}
val := ""
if i < len(valueSpec.Values) && valueSpec.Values[i] != nil {
val = fmt.Sprintf(" = %s", pkg.oneLineNodeDepth(valueSpec.Values[i], depth))
}
return fmt.Sprintf("%s %s%s%s%s", n.Tok, valueSpec.Names[0], typ, val, trailer)
}
return ""
case *ast.FuncDecl:
// Formats func declarations.
name := n.Name.Name
recv := pkg.oneLineNodeDepth(n.Recv, depth)
if len(recv) > 0 {
recv = "(" + recv + ") "
}
fnc := pkg.oneLineNodeDepth(n.Type, depth)
if strings.Index(fnc, "func") == 0 {
fnc = fnc[4:]
}
return fmt.Sprintf("func %s%s%s", recv, name, fnc)
case *ast.TypeSpec:
sep := " "
if n.Assign.IsValid() {
sep = " = "
}
return fmt.Sprintf("type %s%s%s", n.Name.Name, sep, pkg.oneLineNodeDepth(n.Type, depth))
case *ast.FuncType:
var params []string
if n.Params != nil {
for _, field := range n.Params.List {
params = append(params, pkg.oneLineField(field, depth))
}
}
needParens := false
var results []string
if n.Results != nil {
needParens = needParens || len(n.Results.List) > 1
for _, field := range n.Results.List {
needParens = needParens || len(field.Names) > 0
results = append(results, pkg.oneLineField(field, depth))
}
}
param := joinStrings(params)
if len(results) == 0 {
return fmt.Sprintf("func(%s)", param)
}
result := joinStrings(results)
if !needParens {
return fmt.Sprintf("func(%s) %s", param, result)
}
return fmt.Sprintf("func(%s) (%s)", param, result)
case *ast.StructType:
if n.Fields == nil || len(n.Fields.List) == 0 {
return "struct{}"
}
return "struct{ ... }"
case *ast.InterfaceType:
if n.Methods == nil || len(n.Methods.List) == 0 {
return "interface{}"
}
return "interface{ ... }"
case *ast.FieldList:
if n == nil || len(n.List) == 0 {
return ""
}
if len(n.List) == 1 {
return pkg.oneLineField(n.List[0], depth)
}
return dotDotDot
case *ast.FuncLit:
return pkg.oneLineNodeDepth(n.Type, depth) + " { ... }"
case *ast.CompositeLit:
typ := pkg.oneLineNodeDepth(n.Type, depth)
if len(n.Elts) == 0 {
return fmt.Sprintf("%s{}", typ)
}
return fmt.Sprintf("%s{ %s }", typ, dotDotDot)
case *ast.ArrayType:
length := pkg.oneLineNodeDepth(n.Len, depth)
element := pkg.oneLineNodeDepth(n.Elt, depth)
return fmt.Sprintf("[%s]%s", length, element)
case *ast.MapType:
key := pkg.oneLineNodeDepth(n.Key, depth)
value := pkg.oneLineNodeDepth(n.Value, depth)
return fmt.Sprintf("map[%s]%s", key, value)
case *ast.CallExpr:
fnc := pkg.oneLineNodeDepth(n.Fun, depth)
var args []string
for _, arg := range n.Args {
args = append(args, pkg.oneLineNodeDepth(arg, depth))
}
return fmt.Sprintf("%s(%s)", fnc, joinStrings(args))
case *ast.UnaryExpr:
return fmt.Sprintf("%s%s", n.Op, pkg.oneLineNodeDepth(n.X, depth))
case *ast.Ident:
return n.Name
default:
// As a fallback, use default formatter for all unknown node types.
buf := new(bytes.Buffer)
format.Node(buf, pkg.fs, node)
s := buf.String()
if strings.Contains(s, "\n") {
return dotDotDot
}
return s
}
}
// oneLineField returns a one-line summary of the field.
func (pkg *Package) oneLineField(field *ast.Field, depth int) string {
var names []string
for _, name := range field.Names {
names = append(names, name.Name)
}
if len(names) == 0 {
return pkg.oneLineNodeDepth(field.Type, depth)
}
return joinStrings(names) + " " + pkg.oneLineNodeDepth(field.Type, depth)
}
// joinStrings formats the input as a comma-separated list,
// but truncates the list at some reasonable length if necessary.
func joinStrings(ss []string) string {
var n int
for i, s := range ss {
n += len(s) + len(", ")
if n > punchedCardWidth {
ss = append(ss[:i:i], "...")
break
}
}
return strings.Join(ss, ", ")
}
// packageDoc prints the docs for the package (package doc plus one-liners of the rest).
func (pkg *Package) packageDoc() {
defer pkg.flush()
if pkg.showInternals() {
pkg.packageClause(false)
}
doc.ToText(&pkg.buf, pkg.doc.Doc, "", indent, indentedWidth)
pkg.newlines(1)
if !pkg.showInternals() {
// Show only package docs for commands.
return
}
pkg.newlines(2) // Guarantee blank line before the components.
pkg.valueSummary(pkg.doc.Consts, false)
pkg.valueSummary(pkg.doc.Vars, false)
pkg.funcSummary(pkg.doc.Funcs, false)
pkg.typeSummary()
pkg.bugs()
}
// showInternals reports whether we should show the internals
// of a package as opposed to just the package docs.
// Used to decide whether to suppress internals for commands.
// Called only by Package.packageDoc.
func (pkg *Package) showInternals() bool {
return pkg.pkg.Name != "main" || showCmd
}
// packageClause prints the package clause.
// The argument boolean, if true, suppresses the output if the
// user's argument is identical to the actual package path or
// is empty, meaning it's the current directory.
func (pkg *Package) packageClause(checkUserPath bool) {
if checkUserPath {
if pkg.userPath == "" || pkg.userPath == pkg.build.ImportPath {
return
}
}
importPath := pkg.build.ImportComment
if importPath == "" {
importPath = pkg.build.ImportPath
}
pkg.Printf("package %s // import %q\n\n", pkg.name, importPath)
if importPath != pkg.build.ImportPath {
pkg.Printf("WARNING: package source is installed in %q\n", pkg.build.ImportPath)
}
}
// valueSummary prints a one-line summary for each set of values and constants.
// If all the types in a constant or variable declaration belong to the same
// type they can be printed by typeSummary, and so can be suppressed here.
func (pkg *Package) valueSummary(values []*doc.Value, showGrouped bool) {
var isGrouped map[*doc.Value]bool
if !showGrouped {
isGrouped = make(map[*doc.Value]bool)
for _, typ := range pkg.doc.Types {
if !isExported(typ.Name) {
continue
}
for _, c := range typ.Consts {
isGrouped[c] = true
}
for _, v := range typ.Vars {
isGrouped[v] = true
}
}
}
for _, value := range values {
if !isGrouped[value] {
if decl := pkg.oneLineNode(value.Decl); decl != "" {
pkg.Printf("%s\n", decl)
}
}
}
}
// funcSummary prints a one-line summary for each function. Constructors
// are printed by typeSummary, below, and so can be suppressed here.
func (pkg *Package) funcSummary(funcs []*doc.Func, showConstructors bool) {
// First, identify the constructors. Don't bother figuring out if they're exported.
var isConstructor map[*doc.Func]bool
if !showConstructors {
isConstructor = make(map[*doc.Func]bool)
for _, typ := range pkg.doc.Types {
if isExported(typ.Name) {
for _, f := range typ.Funcs {
isConstructor[f] = true
}
}
}
}
for _, fun := range funcs {
// Exported functions only. The go/doc package does not include methods here.
if isExported(fun.Name) {
if !isConstructor[fun] {
pkg.Printf("%s\n", pkg.oneLineNode(fun.Decl))
}
}
}
}
// typeSummary prints a one-line summary for each type, followed by its constructors.
func (pkg *Package) typeSummary() {
for _, typ := range pkg.doc.Types {
for _, spec := range typ.Decl.Specs {
typeSpec := spec.(*ast.TypeSpec) // Must succeed.
if isExported(typeSpec.Name.Name) {
pkg.Printf("%s\n", pkg.oneLineNode(typeSpec))
// Now print the consts, vars, and constructors.
for _, c := range typ.Consts {
if decl := pkg.oneLineNode(c.Decl); decl != "" {
pkg.Printf(indent+"%s\n", decl)
}
}
for _, v := range typ.Vars {
if decl := pkg.oneLineNode(v.Decl); decl != "" {
pkg.Printf(indent+"%s\n", decl)
}
}
for _, constructor := range typ.Funcs {
if isExported(constructor.Name) {
pkg.Printf(indent+"%s\n", pkg.oneLineNode(constructor.Decl))
}
}
}
}
}
}
// bugs prints the BUGS information for the package.
// TODO: Provide access to TODOs and NOTEs as well (very noisy so off by default)?
func (pkg *Package) bugs() {
if pkg.doc.Notes["BUG"] == nil {
return
}
pkg.Printf("\n")
for _, note := range pkg.doc.Notes["BUG"] {
pkg.Printf("%s: %v\n", "BUG", note.Body)
}
}
// findValues finds the doc.Values that describe the symbol.
func (pkg *Package) findValues(symbol string, docValues []*doc.Value) (values []*doc.Value) {
for _, value := range docValues {
for _, name := range value.Names {
if match(symbol, name) {
values = append(values, value)
}
}
}
return
}
// findFuncs finds the doc.Funcs that describes the symbol.
func (pkg *Package) findFuncs(symbol string) (funcs []*doc.Func) {
for _, fun := range pkg.doc.Funcs {
if match(symbol, fun.Name) {
funcs = append(funcs, fun)
}
}
return
}
// findTypes finds the doc.Types that describes the symbol.
// If symbol is empty, it finds all exported types.
func (pkg *Package) findTypes(symbol string) (types []*doc.Type) {
for _, typ := range pkg.doc.Types {
if symbol == "" && isExported(typ.Name) || match(symbol, typ.Name) {
types = append(types, typ)
}
}
return
}
// findTypeSpec returns the ast.TypeSpec within the declaration that defines the symbol.
// The name must match exactly.
func (pkg *Package) findTypeSpec(decl *ast.GenDecl, symbol string) *ast.TypeSpec {
for _, spec := range decl.Specs {
typeSpec := spec.(*ast.TypeSpec) // Must succeed.
if symbol == typeSpec.Name.Name {
return typeSpec
}
}
return nil
}
// symbolDoc prints the docs for symbol. There may be multiple matches.
// If symbol matches a type, output includes its methods factories and associated constants.
// If there is no top-level symbol, symbolDoc looks for methods that match.
func (pkg *Package) symbolDoc(symbol string) bool {
defer pkg.flush()
found := false
// Functions.
for _, fun := range pkg.findFuncs(symbol) {
if !found {
pkg.packageClause(true)
}
// Symbol is a function.
decl := fun.Decl
decl.Body = nil
pkg.emit(fun.Doc, decl)
found = true
}
// Constants and variables behave the same.
values := pkg.findValues(symbol, pkg.doc.Consts)
values = append(values, pkg.findValues(symbol, pkg.doc.Vars)...)
// A declaration like
// const ( c = 1; C = 2 )
// could be printed twice if the -u flag is set, as it matches twice.
// So we remember which declarations we've printed to avoid duplication.
printed := make(map[*ast.GenDecl]bool)
for _, value := range values {
// Print each spec only if there is at least one exported symbol in it.
// (See issue 11008.)
// TODO: Should we elide unexported symbols from a single spec?
// It's an unlikely scenario, probably not worth the trouble.
// TODO: Would be nice if go/doc did this for us.
specs := make([]ast.Spec, 0, len(value.Decl.Specs))
var typ ast.Expr
for _, spec := range value.Decl.Specs {
vspec := spec.(*ast.ValueSpec)
// The type name may carry over from a previous specification in the
// case of constants and iota.
if vspec.Type != nil {
typ = vspec.Type
}
for _, ident := range vspec.Names {
if isExported(ident.Name) {
if vspec.Type == nil && vspec.Values == nil && typ != nil {
// This a standalone identifier, as in the case of iota usage.
// Thus, assume the type comes from the previous type.
vspec.Type = &ast.Ident{
Name: string(pkg.oneLineNode(typ)),
NamePos: vspec.End() - 1,
}
}
specs = append(specs, vspec)
typ = nil // Only inject type on first exported identifier
break
}
}
}
if len(specs) == 0 || printed[value.Decl] {
continue
}
value.Decl.Specs = specs
if !found {
pkg.packageClause(true)
}
pkg.emit(value.Doc, value.Decl)
printed[value.Decl] = true
found = true
}
// Types.
for _, typ := range pkg.findTypes(symbol) {
if !found {
pkg.packageClause(true)
}
decl := typ.Decl
spec := pkg.findTypeSpec(decl, typ.Name)
trimUnexportedElems(spec)
// If there are multiple types defined, reduce to just this one.
if len(decl.Specs) > 1 {
decl.Specs = []ast.Spec{spec}
}
pkg.emit(typ.Doc, decl)
// Show associated methods, constants, etc.
if len(typ.Consts) > 0 || len(typ.Vars) > 0 || len(typ.Funcs) > 0 || len(typ.Methods) > 0 {
pkg.Printf("\n")
}
pkg.valueSummary(typ.Consts, true)
pkg.valueSummary(typ.Vars, true)
pkg.funcSummary(typ.Funcs, true)
pkg.funcSummary(typ.Methods, true)
found = true
}
if !found {
// See if there are methods.
if !pkg.printMethodDoc("", symbol) {
return false
}
}
return true
}
// trimUnexportedElems modifies spec in place to elide unexported fields from
// structs and methods from interfaces (unless the unexported flag is set).
func trimUnexportedElems(spec *ast.TypeSpec) {
if unexported {
return
}
switch typ := spec.Type.(type) {
case *ast.StructType:
typ.Fields = trimUnexportedFields(typ.Fields, false)
case *ast.InterfaceType:
typ.Methods = trimUnexportedFields(typ.Methods, true)
}
}
// trimUnexportedFields returns the field list trimmed of unexported fields.
func trimUnexportedFields(fields *ast.FieldList, isInterface bool) *ast.FieldList {
what := "methods"
if !isInterface {
what = "fields"
}
trimmed := false
list := make([]*ast.Field, 0, len(fields.List))
for _, field := range fields.List {
names := field.Names
if len(names) == 0 {
// Embedded type. Use the name of the type. It must be of the form ident or
// pkg.ident (for structs and interfaces), or *ident or *pkg.ident (structs only).
// Nothing else is allowed.
ty := field.Type
if se, ok := field.Type.(*ast.StarExpr); !isInterface && ok {
// The form *ident or *pkg.ident is only valid on
// embedded types in structs.
ty = se.X
}
switch ident := ty.(type) {
case *ast.Ident:
if isInterface && ident.Name == "error" && ident.Obj == nil {
// For documentation purposes, we consider the builtin error
// type special when embedded in an interface, such that it
// always gets shown publicly.
list = append(list, field)
continue
}
names = []*ast.Ident{ident}
case *ast.SelectorExpr:
// An embedded type may refer to a type in another package.
names = []*ast.Ident{ident.Sel}
}
if names == nil {
// Can only happen if AST is incorrect. Safe to continue with a nil list.
log.Print("invalid program: unexpected type for embedded field")
}
}
// Trims if any is unexported. Good enough in practice.
ok := true
for _, name := range names {
if !isExported(name.Name) {
trimmed = true
ok = false
break
}
}
if ok {
list = append(list, field)
}
}
if !trimmed {
return fields
}
unexportedField := &ast.Field{
Type: &ast.Ident{
// Hack: printer will treat this as a field with a named type.
// Setting Name and NamePos to ("", fields.Closing-1) ensures that
// when Pos and End are called on this field, they return the
// position right before closing '}' character.
Name: "",
NamePos: fields.Closing - 1,
},
Comment: &ast.CommentGroup{
List: []*ast.Comment{{Text: fmt.Sprintf("// Has unexported %s.\n", what)}},
},
}
return &ast.FieldList{
Opening: fields.Opening,
List: append(list, unexportedField),
Closing: fields.Closing,
}
}
// printMethodDoc prints the docs for matches of symbol.method.
// If symbol is empty, it prints all methods that match the name.
// It reports whether it found any methods.
func (pkg *Package) printMethodDoc(symbol, method string) bool {
defer pkg.flush()
types := pkg.findTypes(symbol)
if types == nil {
if symbol == "" {
return false
}
pkg.Fatalf("symbol %s is not a type in package %s installed in %q", symbol, pkg.name, pkg.build.ImportPath)
}
found := false
for _, typ := range types {
if len(typ.Methods) > 0 {
for _, meth := range typ.Methods {
if match(method, meth.Name) {
decl := meth.Decl
decl.Body = nil
pkg.emit(meth.Doc, decl)
found = true
}
}
continue
}
// Type may be an interface. The go/doc package does not attach
// an interface's methods to the doc.Type. We need to dig around.
spec := pkg.findTypeSpec(typ.Decl, typ.Name)
inter, ok := spec.Type.(*ast.InterfaceType)
if !ok {
// Not an interface type.
continue
}
for _, iMethod := range inter.Methods.List {
// This is an interface, so there can be only one name.
// TODO: Anonymous methods (embedding)
if len(iMethod.Names) == 0 {
continue
}
name := iMethod.Names[0].Name
if match(method, name) {
if iMethod.Doc != nil {
for _, comment := range iMethod.Doc.List {
doc.ToText(&pkg.buf, comment.Text, "", indent, indentedWidth)
}
}
s := pkg.oneLineNode(iMethod.Type)
// Hack: s starts "func" but there is no name present.
// We could instead build a FuncDecl but it's not worthwhile.
lineComment := ""
if iMethod.Comment != nil {
lineComment = fmt.Sprintf(" %s", iMethod.Comment.List[0].Text)
}
pkg.Printf("func %s%s%s\n", name, s[4:], lineComment)
found = true
}
}
}
return found
}
// printFieldDoc prints the docs for matches of symbol.fieldName.
// It reports whether it found any field.
// Both symbol and fieldName must be non-empty or it returns false.
func (pkg *Package) printFieldDoc(symbol, fieldName string) bool {
if symbol == "" || fieldName == "" {
return false
}
defer pkg.flush()
types := pkg.findTypes(symbol)
if types == nil {
pkg.Fatalf("symbol %s is not a type in package %s installed in %q", symbol, pkg.name, pkg.build.ImportPath)
}
found := false
numUnmatched := 0
for _, typ := range types {
// Type must be a struct.
spec := pkg.findTypeSpec(typ.Decl, typ.Name)
structType, ok := spec.Type.(*ast.StructType)
if !ok {
// Not a struct type.
continue
}
for _, field := range structType.Fields.List {
// TODO: Anonymous fields.
for _, name := range field.Names {
if !match(fieldName, name.Name) {
numUnmatched++
continue
}
if !found {
pkg.Printf("type %s struct {\n", typ.Name)
}
if field.Doc != nil {
for _, comment := range field.Doc.List {
doc.ToText(&pkg.buf, comment.Text, indent, indent, indentedWidth)
}
}
s := pkg.oneLineNode(field.Type)
lineComment := ""
if field.Comment != nil {
lineComment = fmt.Sprintf(" %s", field.Comment.List[0].Text)
}
pkg.Printf("%s%s %s%s\n", indent, name, s, lineComment)
found = true
}
}
}
if found {
if numUnmatched > 0 {
pkg.Printf("\n // ... other fields elided ...\n")
}
pkg.Printf("}\n")
}
return found
}
// methodDoc prints the docs for matches of symbol.method.
func (pkg *Package) methodDoc(symbol, method string) bool {
defer pkg.flush()
return pkg.printMethodDoc(symbol, method)
}
// fieldDoc prints the docs for matches of symbol.field.
func (pkg *Package) fieldDoc(symbol, field string) bool {
defer pkg.flush()
return pkg.printFieldDoc(symbol, field)
}
// match reports whether the user's symbol matches the program's.
// A lower-case character in the user's string matches either case in the program's.
// The program string must be exported.
func match(user, program string) bool {
if !isExported(program) {
return false
}
if matchCase {
return user == program
}
for _, u := range user {
p, w := utf8.DecodeRuneInString(program)
program = program[w:]
if u == p {
continue
}
if unicode.IsLower(u) && simpleFold(u) == simpleFold(p) {
continue
}
return false
}
return program == ""
}
// simpleFold returns the minimum rune equivalent to r
// under Unicode-defined simple case folding.
func simpleFold(r rune) rune {
for {
r1 := unicode.SimpleFold(r)
if r1 <= r {
return r1 // wrapped around, found min
}
r = r1
}
}