import "reflect"
type T struct {
- f float32
- g float32
+ F float32
+ G float32
- s string
- t string
+ S string
+ T string
- u uint32
- v uint32
+ U uint32
+ V uint32
- w uint32
- x uint32
+ W uint32
+ X uint32
- y uint32
- z uint32
+ Y uint32
+ Z uint32
}
func add(s, t string) string {
func main() {
var x T
- x.f = 1.0
- x.g = x.f
- x.s = add("abc", "def")
- x.t = add("abc", "def")
- x.u = 1
- x.v = 2
- x.w = 1 << 28
- x.x = 2 << 28
- x.y = 0x12345678
- x.z = x.y
+ x.F = 1.0
+ x.G = x.F
+ x.S = add("abc", "def")
+ x.T = add("abc", "def")
+ x.U = 1
+ x.V = 2
+ x.W = 1 << 28
+ x.X = 2 << 28
+ x.Y = 0x12345678
+ x.Z = x.Y
// check mem and string
v := reflect.ValueOf(x)
-fd30c132d1bd
+c1702f36df03
The first line of this file holds the Mercurial revision number of the
last merge done from the master library sources.
toolexeclibgoexpdir = $(toolexeclibgodir)/exp
toolexeclibgoexp_DATA = \
- exp/datafmt.gox \
exp/gui.gox \
exp/norm.gox \
exp/regexp.gox
go_encoding_pem_files = \
go/encoding/pem/pem.go
-go_exp_datafmt_files = \
- go/exp/datafmt/datafmt.go \
- go/exp/datafmt/parser.go
go_exp_gui_files = \
go/exp/gui/gui.go
go_exp_norm_files = \
encoding/git85.lo \
encoding/hex.lo \
encoding/pem.lo \
- exp/datafmt.lo \
exp/gui.lo \
exp/norm.lo \
exp/regexp.lo \
@$(CHECK)
.PHONY: encoding/pem/check
-exp/datafmt.lo: $(go_exp_datafmt_files) bytes.gox fmt.gox go/scanner.gox \
- go/token.gox io.gox os.gox reflect.gox runtime.gox \
- strconv.gox strings.gox
- $(BUILDPACKAGE)
-exp/datafmt/check: $(CHECK_DEPS)
- @$(MKDIR_P) exp/datafmt
- @$(CHECK)
-.PHONY: exp/datafmt/check
-
exp/gui.lo: $(go_exp_gui_files) image.gox image/draw.gox os.gox
$(BUILDPACKAGE)
exp/gui/check: $(CHECK_DEPS)
encoding/pem.gox: encoding/pem.lo
$(BUILDGOX)
-exp/datafmt.gox: exp/datafmt.lo
- $(BUILDGOX)
exp/gui.gox: exp/gui.lo
$(BUILDGOX)
exp/norm.gox: exp/norm.lo
encoding/git85/check \
encoding/hex/check \
encoding/pem/check \
- exp/datafmt/check \
exp/norm/check \
exp/regexp/check \
exp/regexp/syntax/check \
crypto/x509/pkix.lo debug/dwarf.lo debug/elf.lo debug/gosym.lo \
debug/macho.lo debug/pe.lo encoding/ascii85.lo \
encoding/base32.lo encoding/base64.lo encoding/binary.lo \
- encoding/git85.lo encoding/hex.lo encoding/pem.lo \
- exp/datafmt.lo exp/gui.lo exp/norm.lo exp/regexp.lo \
- exp/gui/x11.lo exp/regexp/syntax.lo exp/template/html.lo \
- go/ast.lo go/build.lo go/doc.lo go/parser.lo go/printer.lo \
- go/scanner.lo go/token.lo go/typechecker.lo go/types.lo \
- hash/adler32.lo hash/crc32.lo hash/crc64.lo hash/fnv.lo \
- http/cgi.lo http/fcgi.lo http/httptest.lo http/pprof.lo \
- http/spdy.lo image/bmp.lo image/draw.lo image/gif.lo \
- image/jpeg.lo image/png.lo image/tiff.lo image/ycbcr.lo \
- index/suffixarray.lo io/ioutil.lo mime/multipart.lo \
- net/dict.lo net/textproto.lo old/template.lo \
+ encoding/git85.lo encoding/hex.lo encoding/pem.lo exp/gui.lo \
+ exp/norm.lo exp/regexp.lo exp/gui/x11.lo exp/regexp/syntax.lo \
+ exp/template/html.lo go/ast.lo go/build.lo go/doc.lo \
+ go/parser.lo go/printer.lo go/scanner.lo go/token.lo \
+ go/typechecker.lo go/types.lo hash/adler32.lo hash/crc32.lo \
+ hash/crc64.lo hash/fnv.lo http/cgi.lo http/fcgi.lo \
+ http/httptest.lo http/pprof.lo http/spdy.lo image/bmp.lo \
+ image/draw.lo image/gif.lo image/jpeg.lo image/png.lo \
+ image/tiff.lo image/ycbcr.lo index/suffixarray.lo io/ioutil.lo \
+ mime/multipart.lo net/dict.lo net/textproto.lo old/template.lo \
$(am__DEPENDENCIES_1) os/user.lo os/signal.lo path/filepath.lo \
rpc/jsonrpc.lo runtime/debug.lo runtime/pprof.lo \
sync/atomic.lo sync/atomic_c.lo syscalls/syscall.lo \
toolexeclibgoexpdir = $(toolexeclibgodir)/exp
toolexeclibgoexp_DATA = \
- exp/datafmt.gox \
exp/gui.gox \
exp/norm.gox \
exp/regexp.gox
go_encoding_pem_files = \
go/encoding/pem/pem.go
-go_exp_datafmt_files = \
- go/exp/datafmt/datafmt.go \
- go/exp/datafmt/parser.go
-
go_exp_gui_files = \
go/exp/gui/gui.go
encoding/git85.lo \
encoding/hex.lo \
encoding/pem.lo \
- exp/datafmt.lo \
exp/gui.lo \
exp/norm.lo \
exp/regexp.lo \
encoding/git85/check \
encoding/hex/check \
encoding/pem/check \
- exp/datafmt/check \
exp/norm/check \
exp/regexp/check \
exp/regexp/syntax/check \
@$(CHECK)
.PHONY: encoding/pem/check
-exp/datafmt.lo: $(go_exp_datafmt_files) bytes.gox fmt.gox go/scanner.gox \
- go/token.gox io.gox os.gox reflect.gox runtime.gox \
- strconv.gox strings.gox
- $(BUILDPACKAGE)
-exp/datafmt/check: $(CHECK_DEPS)
- @$(MKDIR_P) exp/datafmt
- @$(CHECK)
-.PHONY: exp/datafmt/check
-
exp/gui.lo: $(go_exp_gui_files) image.gox image/draw.gox os.gox
$(BUILDPACKAGE)
exp/gui/check: $(CHECK_DEPS)
encoding/pem.gox: encoding/pem.lo
$(BUILDGOX)
-exp/datafmt.gox: exp/datafmt.lo
- $(BUILDGOX)
exp/gui.gox: exp/gui.lo
$(BUILDGOX)
exp/norm.gox: exp/norm.lo
+++ /dev/null
-// Copyright 2009 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 datafmt implements syntax-directed, type-driven formatting
- of arbitrary data structures. Formatting a data structure consists of
- two phases: first, a parser reads a format specification and builds a
- "compiled" format. Then, the format can be applied repeatedly to
- arbitrary values. Applying a format to a value evaluates to a []byte
- containing the formatted value bytes, or nil.
-
- A format specification is a set of package declarations and format rules:
-
- Format = [ Entry { ";" Entry } [ ";" ] ] .
- Entry = PackageDecl | FormatRule .
-
- (The syntax of a format specification is presented in the same EBNF
- notation as used in the Go language specification. The syntax of white
- space, comments, identifiers, and string literals is the same as in Go.)
-
- A package declaration binds a package name (such as 'ast') to a
- package import path (such as '"go/ast"'). Each package used (in
- a type name, see below) must be declared once before use.
-
- PackageDecl = PackageName ImportPath .
- PackageName = identifier .
- ImportPath = string .
-
- A format rule binds a rule name to a format expression. A rule name
- may be a type name or one of the special names 'default' or '/'.
- A type name may be the name of a predeclared type (for example, 'int',
- 'float32', etc.), the package-qualified name of a user-defined type
- (for example, 'ast.MapType'), or an identifier indicating the structure
- of unnamed composite types ('array', 'chan', 'func', 'interface', 'map',
- or 'ptr'). Each rule must have a unique name; rules can be declared in
- any order.
-
- FormatRule = RuleName "=" Expression .
- RuleName = TypeName | "default" | "/" .
- TypeName = [ PackageName "." ] identifier .
-
- To format a value, the value's type name is used to select the format rule
- (there is an override mechanism, see below). The format expression of the
- selected rule specifies how the value is formatted. Each format expression,
- when applied to a value, evaluates to a byte sequence or nil.
-
- In its most general form, a format expression is a list of alternatives,
- each of which is a sequence of operands:
-
- Expression = [ Sequence ] { "|" [ Sequence ] } .
- Sequence = Operand { Operand } .
-
- The formatted result produced by an expression is the result of the first
- alternative sequence that evaluates to a non-nil result; if there is no
- such alternative, the expression evaluates to nil. The result produced by
- an operand sequence is the concatenation of the results of its operands.
- If any operand in the sequence evaluates to nil, the entire sequence
- evaluates to nil.
-
- There are five kinds of operands:
-
- Operand = Literal | Field | Group | Option | Repetition .
-
- Literals evaluate to themselves, with two substitutions. First,
- %-formats expand in the manner of fmt.Printf, with the current value
- passed as the parameter. Second, the current indentation (see below)
- is inserted after every newline or form feed character.
-
- Literal = string .
-
- This table shows string literals applied to the value 42 and the
- corresponding formatted result:
-
- "foo" foo
- "%x" 2a
- "x = %d" x = 42
- "%#x = %d" 0x2a = 42
-
- A field operand is a field name optionally followed by an alternate
- rule name. The field name may be an identifier or one of the special
- names @ or *.
-
- Field = FieldName [ ":" RuleName ] .
- FieldName = identifier | "@" | "*" .
-
- If the field name is an identifier, the current value must be a struct,
- and there must be a field with that name in the struct. The same lookup
- rules apply as in the Go language (for instance, the name of an anonymous
- field is the unqualified type name). The field name denotes the field
- value in the struct. If the field is not found, formatting is aborted
- and an error message is returned. (TODO consider changing the semantics
- such that if a field is not found, it evaluates to nil).
-
- The special name '@' denotes the current value.
-
- The meaning of the special name '*' depends on the type of the current
- value:
-
- array, slice types array, slice element (inside {} only, see below)
- interfaces value stored in interface
- pointers value pointed to by pointer
-
- (Implementation restriction: channel, function and map types are not
- supported due to missing reflection support).
-
- Fields are evaluated as follows: If the field value is nil, or an array
- or slice element does not exist, the result is nil (see below for details
- on array/slice elements). If the value is not nil the field value is
- formatted (recursively) using the rule corresponding to its type name,
- or the alternate rule name, if given.
-
- The following example shows a complete format specification for a
- struct 'myPackage.Point'. Assume the package
-
- package myPackage // in directory myDir/myPackage
- type Point struct {
- name string;
- x, y int;
- }
-
- Applying the format specification
-
- myPackage "myDir/myPackage";
- int = "%d";
- hexInt = "0x%x";
- string = "---%s---";
- myPackage.Point = name "{" x ", " y:hexInt "}";
-
- to the value myPackage.Point{"foo", 3, 15} results in
-
- ---foo---{3, 0xf}
-
- Finally, an operand may be a grouped, optional, or repeated expression.
- A grouped expression ("group") groups a more complex expression (body)
- so that it can be used in place of a single operand:
-
- Group = "(" [ Indentation ">>" ] Body ")" .
- Indentation = Expression .
- Body = Expression .
-
- A group body may be prefixed by an indentation expression followed by '>>'.
- The indentation expression is applied to the current value like any other
- expression and the result, if not nil, is appended to the current indentation
- during the evaluation of the body (see also formatting state, below).
-
- An optional expression ("option") is enclosed in '[]' brackets.
-
- Option = "[" Body "]" .
-
- An option evaluates to its body, except that if the body evaluates to nil,
- the option expression evaluates to an empty []byte. Thus an option's purpose
- is to protect the expression containing the option from a nil operand.
-
- A repeated expression ("repetition") is enclosed in '{}' braces.
-
- Repetition = "{" Body [ "/" Separator ] "}" .
- Separator = Expression .
-
- A repeated expression is evaluated as follows: The body is evaluated
- repeatedly and its results are concatenated until the body evaluates
- to nil. The result of the repetition is the (possibly empty) concatenation,
- but it is never nil. An implicit index is supplied for the evaluation of
- the body: that index is used to address elements of arrays or slices. If
- the corresponding elements do not exist, the field denoting the element
- evaluates to nil (which in turn may terminate the repetition).
-
- The body of a repetition may be followed by a '/' and a "separator"
- expression. If the separator is present, it is invoked between repetitions
- of the body.
-
- The following example shows a complete format specification for formatting
- a slice of unnamed type. Applying the specification
-
- int = "%b";
- array = { * / ", " }; // array is the type name for an unnamed slice
-
- to the value '[]int{2, 3, 5, 7}' results in
-
- 10, 11, 101, 111
-
- Default rule: If a format rule named 'default' is present, it is used for
- formatting a value if no other rule was found. A common default rule is
-
- default = "%v"
-
- to provide default formatting for basic types without having to specify
- a specific rule for each basic type.
-
- Global separator rule: If a format rule named '/' is present, it is
- invoked with the current value between literals. If the separator
- expression evaluates to nil, it is ignored.
-
- For instance, a global separator rule may be used to punctuate a sequence
- of values with commas. The rules:
-
- default = "%v";
- / = ", ";
-
- will format an argument list by printing each one in its default format,
- separated by a comma and a space.
-*/
-package datafmt
-
-import (
- "bytes"
- "fmt"
- "go/token"
- "io"
- "os"
- "reflect"
- "runtime"
-)
-
-// ----------------------------------------------------------------------------
-// Format representation
-
-// Custom formatters implement the Formatter function type.
-// A formatter is invoked with the current formatting state, the
-// value to format, and the rule name under which the formatter
-// was installed (the same formatter function may be installed
-// under different names). The formatter may access the current state
-// to guide formatting and use State.Write to append to the state's
-// output.
-//
-// A formatter must return a boolean value indicating if it evaluated
-// to a non-nil value (true), or a nil value (false).
-//
-type Formatter func(state *State, value interface{}, ruleName string) bool
-
-// A FormatterMap is a set of custom formatters.
-// It maps a rule name to a formatter function.
-//
-type FormatterMap map[string]Formatter
-
-// A parsed format expression is built from the following nodes.
-//
-type (
- expr interface{}
-
- alternatives []expr // x | y | z
-
- sequence []expr // x y z
-
- literal [][]byte // a list of string segments, possibly starting with '%'
-
- field struct {
- fieldName string // including "@", "*"
- ruleName string // "" if no rule name specified
- }
-
- group struct {
- indent, body expr // (indent >> body)
- }
-
- option struct {
- body expr // [body]
- }
-
- repetition struct {
- body, separator expr // {body / separator}
- }
-
- custom struct {
- ruleName string
- fun Formatter
- }
-)
-
-// A Format is the result of parsing a format specification.
-// The format may be applied repeatedly to format values.
-//
-type Format map[string]expr
-
-// ----------------------------------------------------------------------------
-// Formatting
-
-// An application-specific environment may be provided to Format.Apply;
-// the environment is available inside custom formatters via State.Env().
-// Environments must implement copying; the Copy method must return an
-// complete copy of the receiver. This is necessary so that the formatter
-// can save and restore an environment (in case of an absent expression).
-//
-// If the Environment doesn't change during formatting (this is under
-// control of the custom formatters), the Copy function can simply return
-// the receiver, and thus can be very light-weight.
-//
-type Environment interface {
- Copy() Environment
-}
-
-// State represents the current formatting state.
-// It is provided as argument to custom formatters.
-//
-type State struct {
- fmt Format // format in use
- env Environment // user-supplied environment
- errors chan os.Error // not chan *Error (errors <- nil would be wrong!)
- hasOutput bool // true after the first literal has been written
- indent bytes.Buffer // current indentation
- output bytes.Buffer // format output
- linePos token.Position // position of line beginning (Column == 0)
- default_ expr // possibly nil
- separator expr // possibly nil
-}
-
-func newState(fmt Format, env Environment, errors chan os.Error) *State {
- s := new(State)
- s.fmt = fmt
- s.env = env
- s.errors = errors
- s.linePos = token.Position{Line: 1}
-
- // if we have a default rule, cache its expression for fast access
- if x, found := fmt["default"]; found {
- s.default_ = x
- }
-
- // if we have a global separator rule, cache its expression for fast access
- if x, found := fmt["/"]; found {
- s.separator = x
- }
-
- return s
-}
-
-// Env returns the environment passed to Format.Apply.
-func (s *State) Env() interface{} { return s.env }
-
-// LinePos returns the position of the current line beginning
-// in the state's output buffer. Line numbers start at 1.
-//
-func (s *State) LinePos() token.Position { return s.linePos }
-
-// Pos returns the position of the next byte to be written to the
-// output buffer. Line numbers start at 1.
-//
-func (s *State) Pos() token.Position {
- offs := s.output.Len()
- return token.Position{Line: s.linePos.Line, Column: offs - s.linePos.Offset, Offset: offs}
-}
-
-// Write writes data to the output buffer, inserting the indentation
-// string after each newline or form feed character. It cannot return an error.
-//
-func (s *State) Write(data []byte) (int, os.Error) {
- n := 0
- i0 := 0
- for i, ch := range data {
- if ch == '\n' || ch == '\f' {
- // write text segment and indentation
- n1, _ := s.output.Write(data[i0 : i+1])
- n2, _ := s.output.Write(s.indent.Bytes())
- n += n1 + n2
- i0 = i + 1
- s.linePos.Offset = s.output.Len()
- s.linePos.Line++
- }
- }
- n3, _ := s.output.Write(data[i0:])
- return n + n3, nil
-}
-
-type checkpoint struct {
- env Environment
- hasOutput bool
- outputLen int
- linePos token.Position
-}
-
-func (s *State) save() checkpoint {
- saved := checkpoint{nil, s.hasOutput, s.output.Len(), s.linePos}
- if s.env != nil {
- saved.env = s.env.Copy()
- }
- return saved
-}
-
-func (s *State) restore(m checkpoint) {
- s.env = m.env
- s.output.Truncate(m.outputLen)
-}
-
-func (s *State) error(msg string) {
- s.errors <- os.NewError(msg)
- runtime.Goexit()
-}
-
-// TODO At the moment, unnamed types are simply mapped to the default
-// names below. For instance, all unnamed arrays are mapped to
-// 'array' which is not really sufficient. Eventually one may want
-// to be able to specify rules for say an unnamed slice of T.
-//
-
-func typename(typ reflect.Type) string {
- switch typ.Kind() {
- case reflect.Array:
- return "array"
- case reflect.Slice:
- return "array"
- case reflect.Chan:
- return "chan"
- case reflect.Func:
- return "func"
- case reflect.Interface:
- return "interface"
- case reflect.Map:
- return "map"
- case reflect.Ptr:
- return "ptr"
- }
- return typ.String()
-}
-
-func (s *State) getFormat(name string) expr {
- if fexpr, found := s.fmt[name]; found {
- return fexpr
- }
-
- if s.default_ != nil {
- return s.default_
- }
-
- s.error(fmt.Sprintf("no format rule for type: '%s'", name))
- return nil
-}
-
-// eval applies a format expression fexpr to a value. If the expression
-// evaluates internally to a non-nil []byte, that slice is appended to
-// the state's output buffer and eval returns true. Otherwise, eval
-// returns false and the state remains unchanged.
-//
-func (s *State) eval(fexpr expr, value reflect.Value, index int) bool {
- // an empty format expression always evaluates
- // to a non-nil (but empty) []byte
- if fexpr == nil {
- return true
- }
-
- switch t := fexpr.(type) {
- case alternatives:
- // append the result of the first alternative that evaluates to
- // a non-nil []byte to the state's output
- mark := s.save()
- for _, x := range t {
- if s.eval(x, value, index) {
- return true
- }
- s.restore(mark)
- }
- return false
-
- case sequence:
- // append the result of all operands to the state's output
- // unless a nil result is encountered
- mark := s.save()
- for _, x := range t {
- if !s.eval(x, value, index) {
- s.restore(mark)
- return false
- }
- }
- return true
-
- case literal:
- // write separator, if any
- if s.hasOutput {
- // not the first literal
- if s.separator != nil {
- sep := s.separator // save current separator
- s.separator = nil // and disable it (avoid recursion)
- mark := s.save()
- if !s.eval(sep, value, index) {
- s.restore(mark)
- }
- s.separator = sep // enable it again
- }
- }
- s.hasOutput = true
- // write literal segments
- for _, lit := range t {
- if len(lit) > 1 && lit[0] == '%' {
- // segment contains a %-format at the beginning
- if lit[1] == '%' {
- // "%%" is printed as a single "%"
- s.Write(lit[1:])
- } else {
- // use s instead of s.output to get indentation right
- fmt.Fprintf(s, string(lit), value.Interface())
- }
- } else {
- // segment contains no %-formats
- s.Write(lit)
- }
- }
- return true // a literal never evaluates to nil
-
- case *field:
- // determine field value
- switch t.fieldName {
- case "@":
- // field value is current value
-
- case "*":
- // indirection: operation is type-specific
- switch v := value; v.Kind() {
- case reflect.Array:
- if v.Len() <= index {
- return false
- }
- value = v.Index(index)
-
- case reflect.Slice:
- if v.IsNil() || v.Len() <= index {
- return false
- }
- value = v.Index(index)
-
- case reflect.Map:
- s.error("reflection support for maps incomplete")
-
- case reflect.Ptr:
- if v.IsNil() {
- return false
- }
- value = v.Elem()
-
- case reflect.Interface:
- if v.IsNil() {
- return false
- }
- value = v.Elem()
-
- case reflect.Chan:
- s.error("reflection support for chans incomplete")
-
- case reflect.Func:
- s.error("reflection support for funcs incomplete")
-
- default:
- s.error(fmt.Sprintf("error: * does not apply to `%s`", value.Type()))
- }
-
- default:
- // value is value of named field
- var field reflect.Value
- if sval := value; sval.Kind() == reflect.Struct {
- field = sval.FieldByName(t.fieldName)
- if !field.IsValid() {
- // TODO consider just returning false in this case
- s.error(fmt.Sprintf("error: no field `%s` in `%s`", t.fieldName, value.Type()))
- }
- }
- value = field
- }
-
- // determine rule
- ruleName := t.ruleName
- if ruleName == "" {
- // no alternate rule name, value type determines rule
- ruleName = typename(value.Type())
- }
- fexpr = s.getFormat(ruleName)
-
- mark := s.save()
- if !s.eval(fexpr, value, index) {
- s.restore(mark)
- return false
- }
- return true
-
- case *group:
- // remember current indentation
- indentLen := s.indent.Len()
-
- // update current indentation
- mark := s.save()
- s.eval(t.indent, value, index)
- // if the indentation evaluates to nil, the state's output buffer
- // didn't change - either way it's ok to append the difference to
- // the current indentation
- s.indent.Write(s.output.Bytes()[mark.outputLen:s.output.Len()])
- s.restore(mark)
-
- // format group body
- mark = s.save()
- b := true
- if !s.eval(t.body, value, index) {
- s.restore(mark)
- b = false
- }
-
- // reset indentation
- s.indent.Truncate(indentLen)
- return b
-
- case *option:
- // evaluate the body and append the result to the state's output
- // buffer unless the result is nil
- mark := s.save()
- if !s.eval(t.body, value, 0) { // TODO is 0 index correct?
- s.restore(mark)
- }
- return true // an option never evaluates to nil
-
- case *repetition:
- // evaluate the body and append the result to the state's output
- // buffer until a result is nil
- for i := 0; ; i++ {
- mark := s.save()
- // write separator, if any
- if i > 0 && t.separator != nil {
- // nil result from separator is ignored
- mark := s.save()
- if !s.eval(t.separator, value, i) {
- s.restore(mark)
- }
- }
- if !s.eval(t.body, value, i) {
- s.restore(mark)
- break
- }
- }
- return true // a repetition never evaluates to nil
-
- case *custom:
- // invoke the custom formatter to obtain the result
- mark := s.save()
- if !t.fun(s, value.Interface(), t.ruleName) {
- s.restore(mark)
- return false
- }
- return true
- }
-
- panic("unreachable")
- return false
-}
-
-// Eval formats each argument according to the format
-// f and returns the resulting []byte and os.Error. If
-// an error occurred, the []byte contains the partially
-// formatted result. An environment env may be passed
-// in which is available in custom formatters through
-// the state parameter.
-//
-func (f Format) Eval(env Environment, args ...interface{}) ([]byte, os.Error) {
- if f == nil {
- return nil, os.NewError("format is nil")
- }
-
- errors := make(chan os.Error)
- s := newState(f, env, errors)
-
- go func() {
- for _, v := range args {
- fld := reflect.ValueOf(v)
- if !fld.IsValid() {
- errors <- os.NewError("nil argument")
- return
- }
- mark := s.save()
- if !s.eval(s.getFormat(typename(fld.Type())), fld, 0) { // TODO is 0 index correct?
- s.restore(mark)
- }
- }
- errors <- nil // no errors
- }()
-
- err := <-errors
- return s.output.Bytes(), err
-}
-
-// ----------------------------------------------------------------------------
-// Convenience functions
-
-// Fprint formats each argument according to the format f
-// and writes to w. The result is the total number of bytes
-// written and an os.Error, if any.
-//
-func (f Format) Fprint(w io.Writer, env Environment, args ...interface{}) (int, os.Error) {
- data, err := f.Eval(env, args...)
- if err != nil {
- // TODO should we print partial result in case of error?
- return 0, err
- }
- return w.Write(data)
-}
-
-// Print formats each argument according to the format f
-// and writes to standard output. The result is the total
-// number of bytes written and an os.Error, if any.
-//
-func (f Format) Print(args ...interface{}) (int, os.Error) {
- return f.Fprint(os.Stdout, nil, args...)
-}
-
-// Sprint formats each argument according to the format f
-// and returns the resulting string. If an error occurs
-// during formatting, the result string contains the
-// partially formatted result followed by an error message.
-//
-func (f Format) Sprint(args ...interface{}) string {
- var buf bytes.Buffer
- _, err := f.Fprint(&buf, nil, args...)
- if err != nil {
- var i interface{} = args
- fmt.Fprintf(&buf, "--- Sprint(%s) failed: %v", fmt.Sprint(i), err)
- }
- return buf.String()
-}
+++ /dev/null
-// Copyright 2009 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 datafmt
-
-import (
- "fmt"
- "testing"
- "go/token"
-)
-
-var fset = token.NewFileSet()
-
-func parse(t *testing.T, form string, fmap FormatterMap) Format {
- f, err := Parse(fset, "", []byte(form), fmap)
- if err != nil {
- t.Errorf("Parse(%s): %v", form, err)
- return nil
- }
- return f
-}
-
-func verify(t *testing.T, f Format, expected string, args ...interface{}) {
- if f == nil {
- return // allow other tests to run
- }
- result := f.Sprint(args...)
- if result != expected {
- t.Errorf(
- "result : `%s`\nexpected: `%s`\n\n",
- result, expected)
- }
-}
-
-func formatter(s *State, value interface{}, rule_name string) bool {
- switch rule_name {
- case "/":
- fmt.Fprintf(s, "%d %d %d", s.Pos().Line, s.LinePos().Column, s.Pos().Column)
- return true
- case "blank":
- s.Write([]byte{' '})
- return true
- case "int":
- if value.(int)&1 == 0 {
- fmt.Fprint(s, "even ")
- } else {
- fmt.Fprint(s, "odd ")
- }
- return true
- case "nil":
- return false
- case "testing.T":
- s.Write([]byte("testing.T"))
- return true
- }
- panic("unreachable")
- return false
-}
-
-func TestCustomFormatters(t *testing.T) {
- fmap0 := FormatterMap{"/": formatter}
- fmap1 := FormatterMap{"int": formatter, "blank": formatter, "nil": formatter}
- fmap2 := FormatterMap{"testing.T": formatter}
-
- f := parse(t, `int=`, fmap0)
- verify(t, f, ``, 1, 2, 3)
-
- f = parse(t, `int="#"`, nil)
- verify(t, f, `###`, 1, 2, 3)
-
- f = parse(t, `int="#";string="%s"`, fmap0)
- verify(t, f, "#1 0 1#1 0 7#1 0 13\n2 0 0foo2 0 8\n", 1, 2, 3, "\n", "foo", "\n")
-
- f = parse(t, ``, fmap1)
- verify(t, f, `even odd even odd `, 0, 1, 2, 3)
-
- f = parse(t, `/ =@:blank; float64="#"`, fmap1)
- verify(t, f, `# # #`, 0.0, 1.0, 2.0)
-
- f = parse(t, `float64=@:nil`, fmap1)
- verify(t, f, ``, 0.0, 1.0, 2.0)
-
- f = parse(t, `testing "testing"; ptr=*`, fmap2)
- verify(t, f, `testing.T`, t)
-
- // TODO needs more tests
-}
-
-// ----------------------------------------------------------------------------
-// Formatting of basic and simple composite types
-
-func check(t *testing.T, form, expected string, args ...interface{}) {
- f := parse(t, form, nil)
- if f == nil {
- return // allow other tests to run
- }
- result := f.Sprint(args...)
- if result != expected {
- t.Errorf(
- "format : %s\nresult : `%s`\nexpected: `%s`\n\n",
- form, result, expected)
- }
-}
-
-func TestBasicTypes(t *testing.T) {
- check(t, ``, ``)
- check(t, `bool=":%v"`, `:true:false`, true, false)
- check(t, `int="%b %d %o 0x%x"`, `101010 42 52 0x2a`, 42)
-
- check(t, `int="%"`, `%`, 42)
- check(t, `int="%%"`, `%`, 42)
- check(t, `int="**%%**"`, `**%**`, 42)
- check(t, `int="%%%%%%"`, `%%%`, 42)
- check(t, `int="%%%d%%"`, `%42%`, 42)
-
- const i = -42
- const is = `-42`
- check(t, `int ="%d"`, is, i)
- check(t, `int8 ="%d"`, is, int8(i))
- check(t, `int16="%d"`, is, int16(i))
- check(t, `int32="%d"`, is, int32(i))
- check(t, `int64="%d"`, is, int64(i))
-
- const u = 42
- const us = `42`
- check(t, `uint ="%d"`, us, uint(u))
- check(t, `uint8 ="%d"`, us, uint8(u))
- check(t, `uint16="%d"`, us, uint16(u))
- check(t, `uint32="%d"`, us, uint32(u))
- check(t, `uint64="%d"`, us, uint64(u))
-
- const f = 3.141592
- const fs = `3.141592`
- check(t, `float64="%g"`, fs, f)
- check(t, `float32="%g"`, fs, float32(f))
- check(t, `float64="%g"`, fs, float64(f))
-}
-
-func TestArrayTypes(t *testing.T) {
- var a0 [10]int
- check(t, `array="array";`, `array`, a0)
-
- a1 := [...]int{1, 2, 3}
- check(t, `array="array";`, `array`, a1)
- check(t, `array={*}; int="%d";`, `123`, a1)
- check(t, `array={* / ", "}; int="%d";`, `1, 2, 3`, a1)
- check(t, `array={* / *}; int="%d";`, `12233`, a1)
-
- a2 := []interface{}{42, "foo", 3.14}
- check(t, `array={* / ", "}; interface=*; string="bar"; default="%v";`, `42, bar, 3.14`, a2)
-}
-
-func TestChanTypes(t *testing.T) {
- var c0 chan int
- check(t, `chan="chan"`, `chan`, c0)
-
- c1 := make(chan int)
- go func() { c1 <- 42 }()
- check(t, `chan="chan"`, `chan`, c1)
- // check(t, `chan=*`, `42`, c1); // reflection support for chans incomplete
-}
-
-func TestFuncTypes(t *testing.T) {
- var f0 func() int
- check(t, `func="func"`, `func`, f0)
-
- f1 := func() int { return 42 }
- check(t, `func="func"`, `func`, f1)
- // check(t, `func=*`, `42`, f1); // reflection support for funcs incomplete
-}
-
-func TestMapTypes(t *testing.T) {
- var m0 map[string]int
- check(t, `map="map"`, `map`, m0)
-
- m1 := map[string]int{}
- check(t, `map="map"`, `map`, m1)
- // check(t, `map=*`, ``, m1); // reflection support for maps incomplete
-}
-
-func TestPointerTypes(t *testing.T) {
- var p0 *int
- check(t, `ptr="ptr"`, `ptr`, p0)
- check(t, `ptr=*`, ``, p0)
- check(t, `ptr=*|"nil"`, `nil`, p0)
-
- x := 99991
- p1 := &x
- check(t, `ptr="ptr"`, `ptr`, p1)
- check(t, `ptr=*; int="%d"`, `99991`, p1)
-}
-
-func TestDefaultRule(t *testing.T) {
- check(t, `default="%v"`, `42foo3.14`, 42, "foo", 3.14)
- check(t, `default="%v"; int="%x"`, `abcdef`, 10, 11, 12, 13, 14, 15)
- check(t, `default="%v"; int="%x"`, `ab**ef`, 10, 11, "**", 14, 15)
- check(t, `default="%x"; int=@:default`, `abcdef`, 10, 11, 12, 13, 14, 15)
-}
-
-func TestGlobalSeparatorRule(t *testing.T) {
- check(t, `int="%d"; / ="-"`, `1-2-3-4`, 1, 2, 3, 4)
- check(t, `int="%x%x"; / ="*"`, `aa*aa`, 10, 10)
-}
-
-// ----------------------------------------------------------------------------
-// Formatting of a struct
-
-type T1 struct {
- a int
-}
-
-const F1 = `datafmt "datafmt";` +
- `int = "%d";` +
- `datafmt.T1 = "<" a ">";`
-
-func TestStruct1(t *testing.T) { check(t, F1, "<42>", T1{42}) }
-
-// ----------------------------------------------------------------------------
-// Formatting of a struct with an optional field (ptr)
-
-type T2 struct {
- s string
- p *T1
-}
-
-const F2a = F1 +
- `string = "%s";` +
- `ptr = *;` +
- `datafmt.T2 = s ["-" p "-"];`
-
-const F2b = F1 +
- `string = "%s";` +
- `ptr = *;` +
- `datafmt.T2 = s ("-" p "-" | "empty");`
-
-func TestStruct2(t *testing.T) {
- check(t, F2a, "foo", T2{"foo", nil})
- check(t, F2a, "bar-<17>-", T2{"bar", &T1{17}})
- check(t, F2b, "fooempty", T2{"foo", nil})
-}
-
-// ----------------------------------------------------------------------------
-// Formatting of a struct with a repetitive field (slice)
-
-type T3 struct {
- s string
- a []int
-}
-
-const F3a = `datafmt "datafmt";` +
- `default = "%v";` +
- `array = *;` +
- `datafmt.T3 = s {" " a a / ","};`
-
-const F3b = `datafmt "datafmt";` +
- `int = "%d";` +
- `string = "%s";` +
- `array = *;` +
- `nil = ;` +
- `empty = *:nil;` +
- `datafmt.T3 = s [a:empty ": " {a / "-"}]`
-
-func TestStruct3(t *testing.T) {
- check(t, F3a, "foo", T3{"foo", nil})
- check(t, F3a, "foo 00, 11, 22", T3{"foo", []int{0, 1, 2}})
- check(t, F3b, "bar", T3{"bar", nil})
- check(t, F3b, "bal: 2-3-5", T3{"bal", []int{2, 3, 5}})
-}
-
-// ----------------------------------------------------------------------------
-// Formatting of a struct with alternative field
-
-type T4 struct {
- x *int
- a []int
-}
-
-const F4a = `datafmt "datafmt";` +
- `int = "%d";` +
- `ptr = *;` +
- `array = *;` +
- `nil = ;` +
- `empty = *:nil;` +
- `datafmt.T4 = "<" (x:empty x | "-") ">" `
-
-const F4b = `datafmt "datafmt";` +
- `int = "%d";` +
- `ptr = *;` +
- `array = *;` +
- `nil = ;` +
- `empty = *:nil;` +
- `datafmt.T4 = "<" (a:empty {a / ", "} | "-") ">" `
-
-func TestStruct4(t *testing.T) {
- x := 7
- check(t, F4a, "<->", T4{nil, nil})
- check(t, F4a, "<7>", T4{&x, nil})
- check(t, F4b, "<->", T4{nil, nil})
- check(t, F4b, "<2, 3, 7>", T4{nil, []int{2, 3, 7}})
-}
-
-// ----------------------------------------------------------------------------
-// Formatting a struct (documentation example)
-
-type Point struct {
- name string
- x, y int
-}
-
-const FPoint = `datafmt "datafmt";` +
- `int = "%d";` +
- `hexInt = "0x%x";` +
- `string = "---%s---";` +
- `datafmt.Point = name "{" x ", " y:hexInt "}";`
-
-func TestStructPoint(t *testing.T) {
- p := Point{"foo", 3, 15}
- check(t, FPoint, "---foo---{3, 0xf}", p)
-}
-
-// ----------------------------------------------------------------------------
-// Formatting a slice (documentation example)
-
-const FSlice = `int = "%b";` +
- `array = { * / ", " }`
-
-func TestSlice(t *testing.T) { check(t, FSlice, "10, 11, 101, 111", []int{2, 3, 5, 7}) }
-
-// TODO add more tests
+++ /dev/null
-// Copyright 2009 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 datafmt
-
-import (
- "go/scanner"
- "go/token"
- "os"
- "strconv"
- "strings"
-)
-
-// ----------------------------------------------------------------------------
-// Parsing
-
-type parser struct {
- scanner.ErrorVector
- scanner scanner.Scanner
- file *token.File
- pos token.Pos // token position
- tok token.Token // one token look-ahead
- lit string // token literal
-
- packs map[string]string // PackageName -> ImportPath
- rules map[string]expr // RuleName -> Expression
-}
-
-func (p *parser) next() {
- p.pos, p.tok, p.lit = p.scanner.Scan()
- switch p.tok {
- case token.CHAN, token.FUNC, token.INTERFACE, token.MAP, token.STRUCT:
- // Go keywords for composite types are type names
- // returned by reflect. Accept them as identifiers.
- p.tok = token.IDENT // p.lit is already set correctly
- }
-}
-
-func (p *parser) init(fset *token.FileSet, filename string, src []byte) {
- p.ErrorVector.Reset()
- p.file = fset.AddFile(filename, fset.Base(), len(src))
- p.scanner.Init(p.file, src, p, scanner.AllowIllegalChars) // return '@' as token.ILLEGAL w/o error message
- p.next() // initializes pos, tok, lit
- p.packs = make(map[string]string)
- p.rules = make(map[string]expr)
-}
-
-func (p *parser) error(pos token.Pos, msg string) {
- p.Error(p.file.Position(pos), msg)
-}
-
-func (p *parser) errorExpected(pos token.Pos, msg string) {
- msg = "expected " + msg
- if pos == p.pos {
- // the error happened at the current position;
- // make the error message more specific
- msg += ", found '" + p.tok.String() + "'"
- if p.tok.IsLiteral() {
- msg += " " + p.lit
- }
- }
- p.error(pos, msg)
-}
-
-func (p *parser) expect(tok token.Token) token.Pos {
- pos := p.pos
- if p.tok != tok {
- p.errorExpected(pos, "'"+tok.String()+"'")
- }
- p.next() // make progress in any case
- return pos
-}
-
-func (p *parser) parseIdentifier() string {
- name := p.lit
- p.expect(token.IDENT)
- return name
-}
-
-func (p *parser) parseTypeName() (string, bool) {
- pos := p.pos
- name, isIdent := p.parseIdentifier(), true
- if p.tok == token.PERIOD {
- // got a package name, lookup package
- if importPath, found := p.packs[name]; found {
- name = importPath
- } else {
- p.error(pos, "package not declared: "+name)
- }
- p.next()
- name, isIdent = name+"."+p.parseIdentifier(), false
- }
- return name, isIdent
-}
-
-// Parses a rule name and returns it. If the rule name is
-// a package-qualified type name, the package name is resolved.
-// The 2nd result value is true iff the rule name consists of a
-// single identifier only (and thus could be a package name).
-//
-func (p *parser) parseRuleName() (string, bool) {
- name, isIdent := "", false
- switch p.tok {
- case token.IDENT:
- name, isIdent = p.parseTypeName()
- case token.DEFAULT:
- name = "default"
- p.next()
- case token.QUO:
- name = "/"
- p.next()
- default:
- p.errorExpected(p.pos, "rule name")
- p.next() // make progress in any case
- }
- return name, isIdent
-}
-
-func (p *parser) parseString() string {
- s := ""
- if p.tok == token.STRING {
- s, _ = strconv.Unquote(p.lit)
- // Unquote may fail with an error, but only if the scanner found
- // an illegal string in the first place. In this case the error
- // has already been reported.
- p.next()
- return s
- } else {
- p.expect(token.STRING)
- }
- return s
-}
-
-func (p *parser) parseLiteral() literal {
- s := []byte(p.parseString())
-
- // A string literal may contain %-format specifiers. To simplify
- // and speed up printing of the literal, split it into segments
- // that start with "%" possibly followed by a last segment that
- // starts with some other character.
- var list []interface{}
- i0 := 0
- for i := 0; i < len(s); i++ {
- if s[i] == '%' && i+1 < len(s) {
- // the next segment starts with a % format
- if i0 < i {
- // the current segment is not empty, split it off
- list = append(list, s[i0:i])
- i0 = i
- }
- i++ // skip %; let loop skip over char after %
- }
- }
- // the final segment may start with any character
- // (it is empty iff the string is empty)
- list = append(list, s[i0:])
-
- // convert list into a literal
- lit := make(literal, len(list))
- for i := 0; i < len(list); i++ {
- lit[i] = list[i].([]byte)
- }
-
- return lit
-}
-
-func (p *parser) parseField() expr {
- var fname string
- switch p.tok {
- case token.ILLEGAL:
- if p.lit != "@" {
- return nil
- }
- fname = "@"
- p.next()
- case token.MUL:
- fname = "*"
- p.next()
- case token.IDENT:
- fname = p.parseIdentifier()
- default:
- return nil
- }
-
- var ruleName string
- if p.tok == token.COLON {
- p.next()
- ruleName, _ = p.parseRuleName()
- }
-
- return &field{fname, ruleName}
-}
-
-func (p *parser) parseOperand() (x expr) {
- switch p.tok {
- case token.STRING:
- x = p.parseLiteral()
-
- case token.LPAREN:
- p.next()
- x = p.parseExpression()
- if p.tok == token.SHR {
- p.next()
- x = &group{x, p.parseExpression()}
- }
- p.expect(token.RPAREN)
-
- case token.LBRACK:
- p.next()
- x = &option{p.parseExpression()}
- p.expect(token.RBRACK)
-
- case token.LBRACE:
- p.next()
- x = p.parseExpression()
- var div expr
- if p.tok == token.QUO {
- p.next()
- div = p.parseExpression()
- }
- x = &repetition{x, div}
- p.expect(token.RBRACE)
-
- default:
- x = p.parseField() // may be nil
- }
-
- return x
-}
-
-func (p *parser) parseSequence() expr {
- var list []interface{}
-
- for x := p.parseOperand(); x != nil; x = p.parseOperand() {
- list = append(list, x)
- }
-
- // no need for a sequence if list.Len() < 2
- switch len(list) {
- case 0:
- return nil
- case 1:
- return list[0].(expr)
- }
-
- // convert list into a sequence
- seq := make(sequence, len(list))
- for i := 0; i < len(list); i++ {
- seq[i] = list[i].(expr)
- }
- return seq
-}
-
-func (p *parser) parseExpression() expr {
- var list []interface{}
-
- for {
- x := p.parseSequence()
- if x != nil {
- list = append(list, x)
- }
- if p.tok != token.OR {
- break
- }
- p.next()
- }
-
- // no need for an alternatives if list.Len() < 2
- switch len(list) {
- case 0:
- return nil
- case 1:
- return list[0].(expr)
- }
-
- // convert list into a alternatives
- alt := make(alternatives, len(list))
- for i := 0; i < len(list); i++ {
- alt[i] = list[i].(expr)
- }
- return alt
-}
-
-func (p *parser) parseFormat() {
- for p.tok != token.EOF {
- pos := p.pos
-
- name, isIdent := p.parseRuleName()
- switch p.tok {
- case token.STRING:
- // package declaration
- importPath := p.parseString()
-
- // add package declaration
- if !isIdent {
- p.error(pos, "illegal package name: "+name)
- } else if _, found := p.packs[name]; !found {
- p.packs[name] = importPath
- } else {
- p.error(pos, "package already declared: "+name)
- }
-
- case token.ASSIGN:
- // format rule
- p.next()
- x := p.parseExpression()
-
- // add rule
- if _, found := p.rules[name]; !found {
- p.rules[name] = x
- } else {
- p.error(pos, "format rule already declared: "+name)
- }
-
- default:
- p.errorExpected(p.pos, "package declaration or format rule")
- p.next() // make progress in any case
- }
-
- if p.tok == token.SEMICOLON {
- p.next()
- } else {
- break
- }
- }
- p.expect(token.EOF)
-}
-
-func remap(p *parser, name string) string {
- i := strings.Index(name, ".")
- if i >= 0 {
- packageName, suffix := name[0:i], name[i:]
- // lookup package
- if importPath, found := p.packs[packageName]; found {
- name = importPath + suffix
- } else {
- var invalidPos token.Position
- p.Error(invalidPos, "package not declared: "+packageName)
- }
- }
- return name
-}
-
-// Parse parses a set of format productions from source src. Custom
-// formatters may be provided via a map of formatter functions. If
-// there are no errors, the result is a Format and the error is nil.
-// Otherwise the format is nil and a non-empty ErrorList is returned.
-//
-func Parse(fset *token.FileSet, filename string, src []byte, fmap FormatterMap) (Format, os.Error) {
- // parse source
- var p parser
- p.init(fset, filename, src)
- p.parseFormat()
-
- // add custom formatters, if any
- for name, form := range fmap {
- name = remap(&p, name)
- if _, found := p.rules[name]; !found {
- p.rules[name] = &custom{name, form}
- } else {
- var invalidPos token.Position
- p.Error(invalidPos, "formatter already declared: "+name)
- }
- }
-
- return p.rules, p.GetError(scanner.NoMultiples)
-}
func (i I) String() string { return Sprintf("<%d>", int(i)) }
type B struct {
- i I
+ I I
j int
}
}
type S struct {
- f F // a struct field that Formats
- g G // a struct field that GoStrings
+ F F // a struct field that Formats
+ G G // a struct field that GoStrings
}
// A type with a String method with pointer receiver for testing %p
{"%+v", A{1, 2, "a", []int{1, 2}}, `{i:1 j:2 s:a x:[1 2]}`},
// +v on structs with Stringable items
- {"%+v", B{1, 2}, `{i:<1> j:2}`},
- {"%+v", C{1, B{2, 3}}, `{i:1 B:{i:<2> j:3}}`},
+ {"%+v", B{1, 2}, `{I:<1> j:2}`},
+ {"%+v", C{1, B{2, 3}}, `{i:1 B:{I:<2> j:3}}`},
// q on Stringable items
{"%s", I(23), `<23>`},
{"%#v", uint64(1<<64 - 1), "0xffffffffffffffff"},
{"%#v", 1000000000, "1000000000"},
{"%#v", map[string]int{"a": 1, "b": 2}, `map[string] int{"a":1, "b":2}`},
- {"%#v", map[string]B{"a": {1, 2}, "b": {3, 4}}, `map[string] fmt_test.B{"a":fmt_test.B{i:1, j:2}, "b":fmt_test.B{i:3, j:4}}`},
+ {"%#v", map[string]B{"a": {1, 2}, "b": {3, 4}}, `map[string] fmt_test.B{"a":fmt_test.B{I:1, j:2}, "b":fmt_test.B{I:3, j:4}}`},
{"%#v", []string{"a", "b"}, `[]string{"a", "b"}`},
// slices with other formats
// Formatter
{"%x", F(1), "<x=F(1)>"},
{"%x", G(2), "2"},
- {"%+v", S{F(4), G(5)}, "{f:<v=F(4)> g:5}"},
+ {"%+v", S{F(4), G(5)}, "{F:<v=F(4)> G:5}"},
// GoStringer
{"%#v", G(6), "GoString(6)"},
- {"%#v", S{F(7), G(8)}, "fmt_test.S{f:<v=F(7)>, g:GoString(8)}"},
+ {"%#v", S{F(7), G(8)}, "fmt_test.S{F:<v=F(7)>, G:GoString(8)}"},
// %T
{"%T", (4 - 3i), "complex128"},
// the thing inside the interface, not the interface itself.
func getField(v reflect.Value, i int) reflect.Value {
val := v.Field(i)
- if i := val; i.Kind() == reflect.Interface {
- if inter := i.Interface(); inter != nil {
- return reflect.ValueOf(inter)
- }
+ if val.Kind() == reflect.Interface && !val.IsNil() {
+ val = val.Elem()
}
return val
}
p.buf.WriteByte('?')
}
-func (p *pp) badVerb(verb int, val interface{}) {
+func (p *pp) badVerb(verb int, val interface{}, val1 reflect.Value) {
p.add('%')
p.add('!')
p.add(verb)
p.add('(')
- if val == nil {
- p.buf.Write(nilAngleBytes)
- } else {
+ switch {
+ case val != nil:
p.buf.WriteString(reflect.TypeOf(val).String())
p.add('=')
p.printField(val, 'v', false, false, 0)
+ case val1.IsValid():
+ p.buf.WriteString(val1.Type().String())
+ p.add('=')
+ p.printValue(val1, 'v', false, false, 0)
+ default:
+ p.buf.Write(nilAngleBytes)
}
p.add(')')
}
-func (p *pp) fmtBool(v bool, verb int, value interface{}) {
+func (p *pp) fmtBool(v bool, verb int, value interface{}, value1 reflect.Value) {
switch verb {
case 't', 'v':
p.fmt.fmt_boolean(v)
default:
- p.badVerb(verb, value)
+ p.badVerb(verb, value, value1)
}
}
p.fmt.pad(p.runeBuf[0:w])
}
-func (p *pp) fmtInt64(v int64, verb int, value interface{}) {
+func (p *pp) fmtInt64(v int64, verb int, value interface{}, value1 reflect.Value) {
switch verb {
case 'b':
p.fmt.integer(v, 2, signed, ldigits)
if 0 <= v && v <= unicode.MaxRune {
p.fmt.fmt_qc(v)
} else {
- p.badVerb(verb, value)
+ p.badVerb(verb, value, value1)
}
case 'x':
p.fmt.integer(v, 16, signed, ldigits)
case 'X':
p.fmt.integer(v, 16, signed, udigits)
default:
- p.badVerb(verb, value)
+ p.badVerb(verb, value, value1)
}
}
p.fmt.sharp = sharp
}
-func (p *pp) fmtUint64(v uint64, verb int, goSyntax bool, value interface{}) {
+func (p *pp) fmtUint64(v uint64, verb int, goSyntax bool, value interface{}, value1 reflect.Value) {
switch verb {
case 'b':
p.fmt.integer(int64(v), 2, unsigned, ldigits)
if 0 <= v && v <= unicode.MaxRune {
p.fmt.fmt_qc(int64(v))
} else {
- p.badVerb(verb, value)
+ p.badVerb(verb, value, value1)
}
case 'x':
p.fmt.integer(int64(v), 16, unsigned, ldigits)
case 'U':
p.fmtUnicode(int64(v))
default:
- p.badVerb(verb, value)
+ p.badVerb(verb, value, value1)
}
}
-func (p *pp) fmtFloat32(v float32, verb int, value interface{}) {
+func (p *pp) fmtFloat32(v float32, verb int, value interface{}, value1 reflect.Value) {
switch verb {
case 'b':
p.fmt.fmt_fb32(v)
case 'G':
p.fmt.fmt_G32(v)
default:
- p.badVerb(verb, value)
+ p.badVerb(verb, value, value1)
}
}
-func (p *pp) fmtFloat64(v float64, verb int, value interface{}) {
+func (p *pp) fmtFloat64(v float64, verb int, value interface{}, value1 reflect.Value) {
switch verb {
case 'b':
p.fmt.fmt_fb64(v)
case 'G':
p.fmt.fmt_G64(v)
default:
- p.badVerb(verb, value)
+ p.badVerb(verb, value, value1)
}
}
-func (p *pp) fmtComplex64(v complex64, verb int, value interface{}) {
+func (p *pp) fmtComplex64(v complex64, verb int, value interface{}, value1 reflect.Value) {
switch verb {
case 'e', 'E', 'f', 'F', 'g', 'G':
p.fmt.fmt_c64(v, verb)
case 'v':
p.fmt.fmt_c64(v, 'g')
default:
- p.badVerb(verb, value)
+ p.badVerb(verb, value, value1)
}
}
-func (p *pp) fmtComplex128(v complex128, verb int, value interface{}) {
+func (p *pp) fmtComplex128(v complex128, verb int, value interface{}, value1 reflect.Value) {
switch verb {
case 'e', 'E', 'f', 'F', 'g', 'G':
p.fmt.fmt_c128(v, verb)
case 'v':
p.fmt.fmt_c128(v, 'g')
default:
- p.badVerb(verb, value)
+ p.badVerb(verb, value, value1)
}
}
-func (p *pp) fmtString(v string, verb int, goSyntax bool, value interface{}) {
+func (p *pp) fmtString(v string, verb int, goSyntax bool, value interface{}, value1 reflect.Value) {
switch verb {
case 'v':
if goSyntax {
case 'q':
p.fmt.fmt_q(v)
default:
- p.badVerb(verb, value)
+ p.badVerb(verb, value, value1)
}
}
-func (p *pp) fmtBytes(v []byte, verb int, goSyntax bool, depth int, value interface{}) {
+func (p *pp) fmtBytes(v []byte, verb int, goSyntax bool, depth int, value interface{}, value1 reflect.Value) {
if verb == 'v' || verb == 'd' {
if goSyntax {
p.buf.Write(bytesBytes)
case 'q':
p.fmt.fmt_q(s)
default:
- p.badVerb(verb, value)
+ p.badVerb(verb, value, value1)
}
}
case reflect.Chan, reflect.Func, reflect.Map, reflect.Ptr, reflect.Slice, reflect.UnsafePointer:
u = value.Pointer()
default:
- p.badVerb(verb, field)
+ p.badVerb(verb, field, value)
return
}
if goSyntax {
p.add('(')
- p.buf.WriteString(reflect.TypeOf(field).String())
+ p.buf.WriteString(value.Type().String())
p.add(')')
p.add('(')
if u == 0 {
}
}
-func (p *pp) printField(field interface{}, verb int, plus, goSyntax bool, depth int) (wasString bool) {
- if field == nil {
- if verb == 'T' || verb == 'v' {
- p.buf.Write(nilAngleBytes)
- } else {
- p.badVerb(verb, field)
- }
- return false
- }
-
- // Special processing considerations.
- // %T (the value's type) and %p (its address) are special; we always do them first.
- switch verb {
- case 'T':
- p.printField(reflect.TypeOf(field).String(), 's', false, false, 0)
- return false
- case 'p':
- p.fmtPointer(field, reflect.ValueOf(field), verb, goSyntax)
- return false
- }
+func (p *pp) handleMethods(field interface{}, verb int, plus, goSyntax bool, depth int) (wasString, handled bool) {
// Is it a Formatter?
if formatter, ok := field.(Formatter); ok {
+ handled = true
+ wasString = false
defer p.catchPanic(field, verb)
formatter.Format(p, verb)
- return false // this value is not a string
-
+ return
}
// Must not touch flags before Formatter looks at them.
if plus {
p.fmt.plus = false
}
+
// If we're doing Go syntax and the field knows how to supply it, take care of it now.
if goSyntax {
p.fmt.sharp = false
if stringer, ok := field.(GoStringer); ok {
+ wasString = false
+ handled = true
defer p.catchPanic(field, verb)
// Print the result of GoString unadorned.
- p.fmtString(stringer.GoString(), 's', false, field)
- return false // this value is not a string
+ p.fmtString(stringer.GoString(), 's', false, field, reflect.Value{})
+ return
}
} else {
// Is it a Stringer?
if stringer, ok := field.(Stringer); ok {
+ wasString = false
+ handled = true
defer p.catchPanic(field, verb)
p.printField(stringer.String(), verb, plus, false, depth)
- return false // this value is not a string
+ return
}
}
+ handled = false
+ return
+}
+
+func (p *pp) printField(field interface{}, verb int, plus, goSyntax bool, depth int) (wasString bool) {
+ if field == nil {
+ if verb == 'T' || verb == 'v' {
+ p.buf.Write(nilAngleBytes)
+ } else {
+ p.badVerb(verb, field, reflect.Value{})
+ }
+ return false
+ }
+
+ // Special processing considerations.
+ // %T (the value's type) and %p (its address) are special; we always do them first.
+ switch verb {
+ case 'T':
+ p.printField(reflect.TypeOf(field).String(), 's', false, false, 0)
+ return false
+ case 'p':
+ p.fmtPointer(field, reflect.ValueOf(field), verb, goSyntax)
+ return false
+ }
+
+ if wasString, handled := p.handleMethods(field, verb, plus, goSyntax, depth); handled {
+ return wasString
+ }
// Some types can be done without reflection.
switch f := field.(type) {
case bool:
- p.fmtBool(f, verb, field)
+ p.fmtBool(f, verb, field, reflect.Value{})
return false
case float32:
- p.fmtFloat32(f, verb, field)
+ p.fmtFloat32(f, verb, field, reflect.Value{})
return false
case float64:
- p.fmtFloat64(f, verb, field)
+ p.fmtFloat64(f, verb, field, reflect.Value{})
return false
case complex64:
- p.fmtComplex64(complex64(f), verb, field)
+ p.fmtComplex64(complex64(f), verb, field, reflect.Value{})
return false
case complex128:
- p.fmtComplex128(f, verb, field)
+ p.fmtComplex128(f, verb, field, reflect.Value{})
return false
case int:
- p.fmtInt64(int64(f), verb, field)
+ p.fmtInt64(int64(f), verb, field, reflect.Value{})
return false
case int8:
- p.fmtInt64(int64(f), verb, field)
+ p.fmtInt64(int64(f), verb, field, reflect.Value{})
return false
case int16:
- p.fmtInt64(int64(f), verb, field)
+ p.fmtInt64(int64(f), verb, field, reflect.Value{})
return false
case int32:
- p.fmtInt64(int64(f), verb, field)
+ p.fmtInt64(int64(f), verb, field, reflect.Value{})
return false
case int64:
- p.fmtInt64(f, verb, field)
+ p.fmtInt64(f, verb, field, reflect.Value{})
return false
case uint:
- p.fmtUint64(uint64(f), verb, goSyntax, field)
+ p.fmtUint64(uint64(f), verb, goSyntax, field, reflect.Value{})
return false
case uint8:
- p.fmtUint64(uint64(f), verb, goSyntax, field)
+ p.fmtUint64(uint64(f), verb, goSyntax, field, reflect.Value{})
return false
case uint16:
- p.fmtUint64(uint64(f), verb, goSyntax, field)
+ p.fmtUint64(uint64(f), verb, goSyntax, field, reflect.Value{})
return false
case uint32:
- p.fmtUint64(uint64(f), verb, goSyntax, field)
+ p.fmtUint64(uint64(f), verb, goSyntax, field, reflect.Value{})
return false
case uint64:
- p.fmtUint64(f, verb, goSyntax, field)
+ p.fmtUint64(f, verb, goSyntax, field, reflect.Value{})
return false
case uintptr:
- p.fmtUint64(uint64(f), verb, goSyntax, field)
+ p.fmtUint64(uint64(f), verb, goSyntax, field, reflect.Value{})
return false
case string:
- p.fmtString(f, verb, goSyntax, field)
+ p.fmtString(f, verb, goSyntax, field, reflect.Value{})
return verb == 's' || verb == 'v'
case []byte:
- p.fmtBytes(f, verb, goSyntax, depth, field)
+ p.fmtBytes(f, verb, goSyntax, depth, field, reflect.Value{})
return verb == 's'
}
// Need to use reflection
- value := reflect.ValueOf(field)
+ return p.printReflectValue(reflect.ValueOf(field), verb, plus, goSyntax, depth)
+}
+
+// printValue is like printField but starts with a reflect value, not an interface{} value.
+func (p *pp) printValue(value reflect.Value, verb int, plus, goSyntax bool, depth int) (wasString bool) {
+ if !value.IsValid() {
+ if verb == 'T' || verb == 'v' {
+ p.buf.Write(nilAngleBytes)
+ } else {
+ p.badVerb(verb, nil, value)
+ }
+ return false
+ }
+ // Special processing considerations.
+ // %T (the value's type) and %p (its address) are special; we always do them first.
+ switch verb {
+ case 'T':
+ p.printField(value.Type().String(), 's', false, false, 0)
+ return false
+ case 'p':
+ p.fmtPointer(nil, value, verb, goSyntax)
+ return false
+ }
+
+ // Handle values with special methods.
+ // Call always, even when field == nil, because handleMethods clears p.fmt.plus for us.
+ var field interface{}
+ if value.CanInterface() {
+ field = value.Interface()
+ }
+ if wasString, handled := p.handleMethods(field, verb, plus, goSyntax, depth); handled {
+ return wasString
+ }
+
+ return p.printReflectValue(value, verb, plus, goSyntax, depth)
+}
+
+// printReflectValue is the fallback for both printField and printValue.
+// It uses reflect to print the value.
+func (p *pp) printReflectValue(value reflect.Value, verb int, plus, goSyntax bool, depth int) (wasString bool) {
BigSwitch:
switch f := value; f.Kind() {
case reflect.Bool:
- p.fmtBool(f.Bool(), verb, field)
+ p.fmtBool(f.Bool(), verb, nil, value)
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
- p.fmtInt64(f.Int(), verb, field)
+ p.fmtInt64(f.Int(), verb, nil, value)
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
- p.fmtUint64(uint64(f.Uint()), verb, goSyntax, field)
+ p.fmtUint64(uint64(f.Uint()), verb, goSyntax, nil, value)
case reflect.Float32, reflect.Float64:
if f.Type().Size() == 4 {
- p.fmtFloat32(float32(f.Float()), verb, field)
+ p.fmtFloat32(float32(f.Float()), verb, nil, value)
} else {
- p.fmtFloat64(float64(f.Float()), verb, field)
+ p.fmtFloat64(float64(f.Float()), verb, nil, value)
}
case reflect.Complex64, reflect.Complex128:
if f.Type().Size() == 8 {
- p.fmtComplex64(complex64(f.Complex()), verb, field)
+ p.fmtComplex64(complex64(f.Complex()), verb, nil, value)
} else {
- p.fmtComplex128(complex128(f.Complex()), verb, field)
+ p.fmtComplex128(complex128(f.Complex()), verb, nil, value)
}
case reflect.String:
- p.fmtString(f.String(), verb, goSyntax, field)
+ p.fmtString(f.String(), verb, goSyntax, nil, value)
case reflect.Map:
if goSyntax {
p.buf.WriteString(f.Type().String())
p.buf.WriteByte(' ')
}
}
- p.printField(key.Interface(), verb, plus, goSyntax, depth+1)
+ p.printValue(key, verb, plus, goSyntax, depth+1)
p.buf.WriteByte(':')
- p.printField(f.MapIndex(key).Interface(), verb, plus, goSyntax, depth+1)
+ p.printValue(f.MapIndex(key), verb, plus, goSyntax, depth+1)
}
if goSyntax {
p.buf.WriteByte('}')
}
case reflect.Struct:
if goSyntax {
- p.buf.WriteString(reflect.TypeOf(field).String())
+ p.buf.WriteString(value.Type().String())
}
p.add('{')
v := f
p.buf.WriteByte(':')
}
}
- p.printField(getField(v, i).Interface(), verb, plus, goSyntax, depth+1)
+ p.printValue(getField(v, i), verb, plus, goSyntax, depth+1)
}
p.buf.WriteByte('}')
case reflect.Interface:
value := f.Elem()
if !value.IsValid() {
if goSyntax {
- p.buf.WriteString(reflect.TypeOf(field).String())
+ p.buf.WriteString(value.Type().String())
p.buf.Write(nilParenBytes)
} else {
p.buf.Write(nilAngleBytes)
}
} else {
- return p.printField(value.Interface(), verb, plus, goSyntax, depth+1)
+ return p.printValue(value, verb, plus, goSyntax, depth+1)
}
case reflect.Array, reflect.Slice:
// Byte slices are special.
for i := range bytes {
bytes[i] = byte(f.Index(i).Uint())
}
- p.fmtBytes(bytes, verb, goSyntax, depth, field)
+ p.fmtBytes(bytes, verb, goSyntax, depth, nil, value)
return verb == 's'
}
if goSyntax {
- p.buf.WriteString(reflect.TypeOf(field).String())
+ p.buf.WriteString(value.Type().String())
p.buf.WriteByte('{')
} else {
p.buf.WriteByte('[')
p.buf.WriteByte(' ')
}
}
- p.printField(f.Index(i).Interface(), verb, plus, goSyntax, depth+1)
+ p.printValue(f.Index(i), verb, plus, goSyntax, depth+1)
}
if goSyntax {
p.buf.WriteByte('}')
switch a := f.Elem(); a.Kind() {
case reflect.Array, reflect.Slice:
p.buf.WriteByte('&')
- p.printField(a.Interface(), verb, plus, goSyntax, depth+1)
+ p.printValue(a, verb, plus, goSyntax, depth+1)
break BigSwitch
case reflect.Struct:
p.buf.WriteByte('&')
- p.printField(a.Interface(), verb, plus, goSyntax, depth+1)
+ p.printValue(a, verb, plus, goSyntax, depth+1)
break BigSwitch
}
}
if goSyntax {
p.buf.WriteByte('(')
- p.buf.WriteString(reflect.TypeOf(field).String())
+ p.buf.WriteString(value.Type().String())
p.buf.WriteByte(')')
p.buf.WriteByte('(')
if v == 0 {
}
p.fmt0x64(uint64(v), true)
case reflect.Chan, reflect.Func, reflect.UnsafePointer:
- p.fmtPointer(field, value, verb, goSyntax)
+ p.fmtPointer(nil, value, verb, goSyntax)
default:
p.unknownType(f)
}
4 }`},
// structs
- {struct{ x, y int }{42, 991},
- `0 struct { x int; y int } {
- 1 . x: 42
- 2 . y: 991
+ {struct{ X, Y int }{42, 991},
+ `0 struct { X int; Y int } {
+ 1 . X: 42
+ 2 . Y: 991
3 }`},
}
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
-// Package draw provides image composition functions
-// in the style of the Plan 9 graphics library
-// (see http://plan9.bell-labs.com/magic/man2html/2/draw)
-// and the X Render extension.
+// Package draw provides image composition functions.
+//
+// See "The Go image/draw package" for an introduction to this package:
+// http://blog.golang.org/2011/09/go-imagedraw-package.html
package draw
import (
// license that can be found in the LICENSE file.
// Package image implements a basic 2-D image library.
+//
+// See "The Go image package" for an introduction to this package:
+// http://blog.golang.org/2011/09/go-image-package.html
package image
// Config holds an image's color model and dimensions.
func TestInterfaceExtraction(t *testing.T) {
var s struct {
- w io.Writer
+ W io.Writer
}
- s.w = os.Stdout
+ s.W = os.Stdout
v := Indirect(ValueOf(&s)).Field(0).Interface()
- if v != s.w.(interface{}) {
- t.Error("Interface() on interface: ", v, s.w)
+ if v != s.W.(interface{}) {
+ t.Error("Interface() on interface: ", v, s.W)
}
}
}
type S0 struct {
- a, b, c int
+ A, B, C int
D1
D2
}
type S1 struct {
- b int
+ B int
S0
}
type S2 struct {
- a int
+ A int
*S1
}
type S3 struct {
S1x
S2
- d, e int
+ D, E int
*S1y
}
type S4 struct {
*S4
- a int
+ A int
}
var fieldTests = []FTest{
{struct{}{}, "", nil, 0},
- {struct{}{}, "foo", nil, 0},
- {S0{a: 'a'}, "a", []int{0}, 'a'},
- {S0{}, "d", nil, 0},
- {S1{S0: S0{a: 'a'}}, "a", []int{1, 0}, 'a'},
- {S1{b: 'b'}, "b", []int{0}, 'b'},
+ {struct{}{}, "Foo", nil, 0},
+ {S0{A: 'a'}, "A", []int{0}, 'a'},
+ {S0{}, "D", nil, 0},
+ {S1{S0: S0{A: 'a'}}, "A", []int{1, 0}, 'a'},
+ {S1{B: 'b'}, "B", []int{0}, 'b'},
{S1{}, "S0", []int{1}, 0},
- {S1{S0: S0{c: 'c'}}, "c", []int{1, 2}, 'c'},
- {S2{a: 'a'}, "a", []int{0}, 'a'},
+ {S1{S0: S0{C: 'c'}}, "C", []int{1, 2}, 'c'},
+ {S2{A: 'a'}, "A", []int{0}, 'a'},
{S2{}, "S1", []int{1}, 0},
- {S2{S1: &S1{b: 'b'}}, "b", []int{1, 0}, 'b'},
- {S2{S1: &S1{S0: S0{c: 'c'}}}, "c", []int{1, 1, 2}, 'c'},
- {S2{}, "d", nil, 0},
+ {S2{S1: &S1{B: 'b'}}, "B", []int{1, 0}, 'b'},
+ {S2{S1: &S1{S0: S0{C: 'c'}}}, "C", []int{1, 1, 2}, 'c'},
+ {S2{}, "D", nil, 0},
{S3{}, "S1", nil, 0},
- {S3{S2: S2{a: 'a'}}, "a", []int{1, 0}, 'a'},
- {S3{}, "b", nil, 0},
- {S3{d: 'd'}, "d", []int{2}, 0},
- {S3{e: 'e'}, "e", []int{3}, 'e'},
- {S4{a: 'a'}, "a", []int{1}, 'a'},
- {S4{}, "b", nil, 0},
+ {S3{S2: S2{A: 'a'}}, "A", []int{1, 0}, 'a'},
+ {S3{}, "B", nil, 0},
+ {S3{D: 'd'}, "D", []int{2}, 0},
+ {S3{E: 'e'}, "E", []int{3}, 'e'},
+ {S4{A: 'a'}, "A", []int{1}, 'a'},
+ {S4{}, "B", nil, 0},
}
func TestFieldByIndex(t *testing.T) {
}
}
}
+
+type Private struct {
+ x int
+ y **int
+}
+
+func (p *Private) m() {
+}
+
+type Public struct {
+ X int
+ Y **int
+}
+
+func (p *Public) M() {
+}
+
+func TestUnexported(t *testing.T) {
+ var pub Public
+ v := ValueOf(&pub)
+ isValid(v.Elem().Field(0))
+ isValid(v.Elem().Field(1))
+ isValid(v.Elem().FieldByName("X"))
+ isValid(v.Elem().FieldByName("Y"))
+ isValid(v.Type().Method(0).Func)
+ isNonNil(v.Elem().Field(0).Interface())
+ isNonNil(v.Elem().Field(1).Interface())
+ isNonNil(v.Elem().FieldByName("X").Interface())
+ isNonNil(v.Elem().FieldByName("Y").Interface())
+ isNonNil(v.Type().Method(0).Func.Interface())
+
+ var priv Private
+ v = ValueOf(&priv)
+ isValid(v.Elem().Field(0))
+ isValid(v.Elem().Field(1))
+ isValid(v.Elem().FieldByName("x"))
+ isValid(v.Elem().FieldByName("y"))
+ isValid(v.Type().Method(0).Func)
+ shouldPanic(func() { v.Elem().Field(0).Interface() })
+ shouldPanic(func() { v.Elem().Field(1).Interface() })
+ shouldPanic(func() { v.Elem().FieldByName("x").Interface() })
+ shouldPanic(func() { v.Elem().FieldByName("y").Interface() })
+ shouldPanic(func() { v.Type().Method(0).Func.Interface() })
+}
+
+func shouldPanic(f func()) {
+ defer func() {
+ if recover() == nil {
+ panic("did not panic")
+ }
+ }()
+ f()
+}
+
+func isNonNil(x interface{}) {
+ if x == nil {
+ panic("nil interface")
+ }
+}
+
+func isValid(v Value) {
+ if !v.IsValid() {
+ panic("zero Value")
+ }
+}
return true
default:
// Normal equality suffices
- return v1.Interface() == v2.Interface()
+ return valueInterface(v1, false) == valueInterface(v2, false)
}
panic("Not reached")
if iv.kind == Invalid {
panic(&ValueError{"reflect.Value.CanInterface", iv.kind})
}
- // TODO(rsc): Check flagRO too. Decide what to do about asking for
- // interface for a value obtained via an unexported field.
- // If the field were of a known type, say chan int or *sync.Mutex,
- // the caller could interfere with the data after getting the
- // interface. But fmt.Print depends on being able to look.
- // Now that reflect is more efficient the special cases in fmt
- // might be less important.
- return v.InternalMethod == 0
+ return v.InternalMethod == 0 && iv.flag&flagRO == 0
}
// Interface returns v's value as an interface{}.
// (as opposed to Type.Method), Interface cannot return an
// interface value, so it panics.
func (v Value) Interface() interface{} {
- return v.internal().Interface()
+ return valueInterface(v, true)
}
-func (iv internalValue) Interface() interface{} {
+func valueInterface(v Value, safe bool) interface{} {
+ iv := v.internal()
+ return iv.valueInterface(safe)
+}
+
+func (iv internalValue) valueInterface(safe bool) interface{} {
if iv.kind == 0 {
panic(&ValueError{"reflect.Value.Interface", iv.kind})
}
if iv.method {
panic("reflect.Value.Interface: cannot create interface value for method with bound receiver")
}
- /*
- if v.flag()&noExport != 0 {
- panic("reflect.Value.Interface: cannot return value obtained from unexported struct field")
- }
- */
+ if safe && iv.flag&flagRO != 0 {
+ // Do not allow access to unexported values via Interface,
+ // because they might be pointers that should not be
+ // writable or methods or function that should not be callable.
+ panic("reflect.Value.Interface: cannot return value obtained from unexported field or method")
+ }
if iv.kind == Interface {
// Special case: return the element inside the interface.
// Won't recurse further because an interface cannot contain an interface.
if addr == nil {
addr = unsafe.Pointer(new(interface{}))
}
- x := iv.Interface()
+ x := iv.valueInterface(false)
if dst.NumMethod() == 0 {
*(*interface{})(addr) = x
} else {
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