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Diffstat (limited to 'libgo/go/fmt/scan.go')
-rw-r--r--libgo/go/fmt/scan.go70
1 files changed, 49 insertions, 21 deletions
diff --git a/libgo/go/fmt/scan.go b/libgo/go/fmt/scan.go
index 42bc52c..259451d 100644
--- a/libgo/go/fmt/scan.go
+++ b/libgo/go/fmt/scan.go
@@ -35,6 +35,10 @@ type ScanState interface {
ReadRune() (rune int, size int, err os.Error)
// UnreadRune causes the next call to ReadRune to return the same rune.
UnreadRune() os.Error
+ // SkipSpace skips space in the input. Newlines are treated as space
+ // unless the scan operation is Scanln, Fscanln or Sscanln, in which case
+ // a newline is treated as EOF.
+ SkipSpace()
// Token skips space in the input if skipSpace is true, then returns the
// run of Unicode code points c satisfying f(c). If f is nil,
// !unicode.IsSpace(c) is used; that is, the token will hold non-space
@@ -167,7 +171,7 @@ type ssave struct {
// satisfies io.Reader. It will never be called when used as
// intended, so there is no need to make it actually work.
func (s *ss) Read(buf []byte) (n int, err os.Error) {
- return 0, os.ErrorString("ScanState's Read should not be called. Use ReadRune")
+ return 0, os.NewError("ScanState's Read should not be called. Use ReadRune")
}
func (s *ss) ReadRune() (rune int, size int, err os.Error) {
@@ -231,6 +235,7 @@ func (s *ss) UnreadRune() os.Error {
} else {
s.peekRune = s.prevRune
}
+ s.prevRune = -1
s.count--
return nil
}
@@ -240,7 +245,7 @@ func (s *ss) error(err os.Error) {
}
func (s *ss) errorString(err string) {
- panic(scanError{os.ErrorString(err)})
+ panic(scanError{os.NewError(err)})
}
func (s *ss) Token(skipSpace bool, f func(int) bool) (tok []byte, err os.Error) {
@@ -266,6 +271,12 @@ func notSpace(r int) bool {
return !unicode.IsSpace(r)
}
+// skipSpace provides Scan() methods the ability to skip space and newline characters
+// in keeping with the current scanning mode set by format strings and Scan()/Scanln().
+func (s *ss) SkipSpace() {
+ s.skipSpace(false)
+}
+
// readRune is a structure to enable reading UTF-8 encoded code points
// from an io.Reader. It is used if the Reader given to the scanner does
// not already implement io.RuneReader.
@@ -324,7 +335,6 @@ func (r *readRune) ReadRune() (rune int, size int, err os.Error) {
return
}
-
var ssFree = newCache(func() interface{} { return new(ss) })
// Allocate a new ss struct or grab a cached one.
@@ -398,7 +408,6 @@ func (s *ss) skipSpace(stopAtNewline bool) {
}
}
-
// token returns the next space-delimited string from the input. It
// skips white space. For Scanln, it stops at newlines. For Scan,
// newlines are treated as spaces.
@@ -426,8 +435,8 @@ func (s *ss) typeError(field interface{}, expected string) {
s.errorString("expected field of type pointer to " + expected + "; found " + reflect.TypeOf(field).String())
}
-var complexError = os.ErrorString("syntax error scanning complex number")
-var boolError = os.ErrorString("syntax error scanning boolean")
+var complexError = os.NewError("syntax error scanning complex number")
+var boolError = os.NewError("syntax error scanning boolean")
// consume reads the next rune in the input and reports whether it is in the ok string.
// If accept is true, it puts the character into the input token.
@@ -457,6 +466,14 @@ func (s *ss) peek(ok string) bool {
return strings.IndexRune(ok, rune) >= 0
}
+func (s *ss) notEOF() {
+ // Guarantee there is data to be read.
+ if rune := s.getRune(); rune == eof {
+ panic(os.EOF)
+ }
+ s.UnreadRune()
+}
+
// accept checks the next rune in the input. If it's a byte (sic) in the string, it puts it in the
// buffer and returns true. Otherwise it return false.
func (s *ss) accept(ok string) bool {
@@ -476,11 +493,13 @@ func (s *ss) okVerb(verb int, okVerbs, typ string) bool {
// scanBool returns the value of the boolean represented by the next token.
func (s *ss) scanBool(verb int) bool {
+ s.skipSpace(false)
+ s.notEOF()
if !s.okVerb(verb, "tv", "boolean") {
return false
}
// Syntax-checking a boolean is annoying. We're not fastidious about case.
- switch s.mustReadRune() {
+ switch s.getRune() {
case '0':
return false
case '1':
@@ -531,8 +550,11 @@ func (s *ss) getBase(verb int) (base int, digits string) {
// scanNumber returns the numerical string with specified digits starting here.
func (s *ss) scanNumber(digits string, haveDigits bool) string {
- if !haveDigits && !s.accept(digits) {
- s.errorString("expected integer")
+ if !haveDigits {
+ s.notEOF()
+ if !s.accept(digits) {
+ s.errorString("expected integer")
+ }
}
for s.accept(digits) {
}
@@ -541,7 +563,8 @@ func (s *ss) scanNumber(digits string, haveDigits bool) string {
// scanRune returns the next rune value in the input.
func (s *ss) scanRune(bitSize int) int64 {
- rune := int64(s.mustReadRune())
+ s.notEOF()
+ rune := int64(s.getRune())
n := uint(bitSize)
x := (rune << (64 - n)) >> (64 - n)
if x != rune {
@@ -575,6 +598,7 @@ func (s *ss) scanInt(verb int, bitSize int) int64 {
return s.scanRune(bitSize)
}
s.skipSpace(false)
+ s.notEOF()
base, digits := s.getBase(verb)
haveDigits := false
if verb == 'U' {
@@ -607,6 +631,7 @@ func (s *ss) scanUint(verb int, bitSize int) uint64 {
return uint64(s.scanRune(bitSize))
}
s.skipSpace(false)
+ s.notEOF()
base, digits := s.getBase(verb)
haveDigits := false
if verb == 'U' {
@@ -727,6 +752,7 @@ func (s *ss) scanComplex(verb int, n int) complex128 {
return 0
}
s.skipSpace(false)
+ s.notEOF()
sreal, simag := s.complexTokens()
real := s.convertFloat(sreal, n/2)
imag := s.convertFloat(simag, n/2)
@@ -740,6 +766,7 @@ func (s *ss) convertString(verb int) (str string) {
return ""
}
s.skipSpace(false)
+ s.notEOF()
switch verb {
case 'q':
str = s.quotedString()
@@ -748,16 +775,13 @@ func (s *ss) convertString(verb int) (str string) {
default:
str = string(s.token(true, notSpace)) // %s and %v just return the next word
}
- // Empty strings other than with %q are not OK.
- if len(str) == 0 && verb != 'q' && s.maxWid > 0 {
- s.errorString("Scan: no data for string")
- }
return
}
// quotedString returns the double- or back-quoted string represented by the next input characters.
func (s *ss) quotedString() string {
- quote := s.mustReadRune()
+ s.notEOF()
+ quote := s.getRune()
switch quote {
case '`':
// Back-quoted: Anything goes until EOF or back quote.
@@ -827,6 +851,7 @@ func (s *ss) hexByte() (b byte, ok bool) {
// hexString returns the space-delimited hexpair-encoded string.
func (s *ss) hexString() string {
+ s.notEOF()
for {
b, ok := s.hexByte()
if !ok {
@@ -860,6 +885,7 @@ func (s *ss) scanOne(verb int, field interface{}) {
}
return
}
+
switch v := field.(type) {
case *bool:
*v = s.scanBool(verb)
@@ -894,11 +920,13 @@ func (s *ss) scanOne(verb int, field interface{}) {
case *float32:
if s.okVerb(verb, floatVerbs, "float32") {
s.skipSpace(false)
+ s.notEOF()
*v = float32(s.convertFloat(s.floatToken(), 32))
}
case *float64:
if s.okVerb(verb, floatVerbs, "float64") {
s.skipSpace(false)
+ s.notEOF()
*v = s.convertFloat(s.floatToken(), 64)
}
case *string:
@@ -927,7 +955,7 @@ func (s *ss) scanOne(verb int, field interface{}) {
// For now, can only handle (renamed) []byte.
typ := v.Type()
if typ.Elem().Kind() != reflect.Uint8 {
- goto CantHandle
+ s.errorString("Scan: can't handle type: " + val.Type().String())
}
str := s.convertString(verb)
v.Set(reflect.MakeSlice(typ, len(str), len(str)))
@@ -936,23 +964,23 @@ func (s *ss) scanOne(verb int, field interface{}) {
}
case reflect.Float32, reflect.Float64:
s.skipSpace(false)
+ s.notEOF()
v.SetFloat(s.convertFloat(s.floatToken(), v.Type().Bits()))
case reflect.Complex64, reflect.Complex128:
v.SetComplex(s.scanComplex(verb, v.Type().Bits()))
default:
- CantHandle:
s.errorString("Scan: can't handle type: " + val.Type().String())
}
}
}
-// errorHandler turns local panics into error returns. EOFs are benign.
+// errorHandler turns local panics into error returns.
func errorHandler(errp *os.Error) {
if e := recover(); e != nil {
if se, ok := e.(scanError); ok { // catch local error
- if se.err != os.EOF {
- *errp = se.err
- }
+ *errp = se.err
+ } else if eof, ok := e.(os.Error); ok && eof == os.EOF { // out of input
+ *errp = eof
} else {
panic(e)
}
generated by cgit v1.1 at 2025-04-14 22:19:30 +0000