mv src/lib to src/pkg

tests: all.bash passes, gobuild still works, godoc still works.

R=rsc
OCL=30096
CL=30102

1 files changed, 331 insertions, 0 deletions

diff --git a/src/pkg/json/generic.go b/src/pkg/json/generic.go
new file mode 100644
index 000000000..e3194eb17
--- /dev/null
+++ b/src/pkg/json/generic.go
@@ -0,0 +1,331 @@
+// 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.
+
+// Generic representation of JSON objects.
+
+package json
+
+import (
+	"container/vector";
+	"fmt";
+	"json";
+	"math";
+	"strconv";
+	"strings";
+)
+
+// Integers identifying the data type in the Json interface.
+const (
+	StringKind = iota;
+	NumberKind;
+	MapKind;		// JSON term is "Object", but in Go, it's a map
+	ArrayKind;
+	BoolKind;
+	NullKind;
+)
+
+// The Json interface is implemented by all JSON objects.
+type Json interface {
+	Kind() int;		// StringKind, NumberKind, etc.
+	String() string;	// a string form (any kind)
+	Number() float64;	// numeric form (NumberKind)
+	Bool() bool;		// boolean (BoolKind)
+	Get(s string) Json;	// field lookup (MapKind)
+	Elem(i int) Json;	// element lookup (ArrayKind)
+	Len() int;		// length (ArrayKind, MapKind)
+}
+
+// JsonToString returns the textual JSON syntax representation
+// for the JSON object j.
+//
+// JsonToString differs from j.String() in the handling
+// of string objects.  If j represents the string abc,
+// j.String() == `abc`, but JsonToString(j) == `"abc"`.
+func JsonToString(j Json) string {
+	if j == nil {
+		return "null"
+	}
+	if j.Kind() == StringKind {
+		return Quote(j.String())
+	}
+	return j.String()
+}
+
+type _Null struct { }
+
+// Null is the JSON object representing the null data object.
+var Null Json = &_Null{}
+
+func (*_Null) Kind() int { return NullKind }
+func (*_Null) String() string { return "null" }
+func (*_Null) Number() float64 { return 0 }
+func (*_Null) Bool() bool { return false }
+func (*_Null) Get(s string) Json { return Null }
+func (*_Null) Elem(int) Json { return Null }
+func (*_Null) Len() int { return 0 }
+
+type _String struct { s string; _Null }
+func (j *_String) Kind() int { return StringKind }
+func (j *_String) String() string { return j.s }
+
+type _Number struct { f float64; _Null }
+func (j *_Number) Kind() int { return NumberKind }
+func (j *_Number) Number() float64 { return j.f }
+func (j *_Number) String() string {
+	if math.Floor(j.f) == j.f {
+		return fmt.Sprintf("%.0f", j.f);
+	}
+	return fmt.Sprintf("%g", j.f);
+}
+
+type _Array struct { a *vector.Vector; _Null }
+func (j *_Array) Kind() int { return ArrayKind }
+func (j *_Array) Len() int { return j.a.Len() }
+func (j *_Array) Elem(i int) Json {
+	if i < 0 || i >= j.a.Len() {
+		return Null
+	}
+	return j.a.At(i).(Json)
+}
+func (j *_Array) String() string {
+	s := "[";
+	for i := 0; i < j.a.Len(); i++ {
+		if i > 0 {
+			s += ",";
+		}
+		s += JsonToString(j.a.At(i).(Json));
+	}
+	s += "]";
+	return s;
+}
+
+type _Bool struct { b bool; _Null }
+func (j *_Bool) Kind() int { return BoolKind }
+func (j *_Bool) Bool() bool { return j.b }
+func (j *_Bool) String() string {
+	if j.b {
+		return "true"
+	}
+	return "false"
+}
+
+type _Map struct { m map[string]Json; _Null }
+func (j *_Map) Kind() int { return MapKind }
+func (j *_Map) Len() int { return len(j.m) }
+func (j *_Map) Get(s string) Json {
+	if j.m == nil {
+		return Null
+	}
+	v, ok := j.m[s];
+	if !ok {
+		return Null
+	}
+	return v;
+}
+func (j *_Map) String() string {
+	s := "{";
+	first := true;
+	for k,v := range j.m {
+		if first {
+			first = false;
+		} else {
+			s += ",";
+		}
+		s += Quote(k);
+		s += ":";
+		s += JsonToString(v);
+	}
+	s += "}";
+	return s;
+}
+
+// Walk evaluates path relative to the JSON object j.
+// Path is taken as a sequence of slash-separated field names
+// or numbers that can be used to index into JSON map and
+// array objects.
+//
+// For example, if j is the JSON object for
+// {"abc": [true, false]}, then Walk(j, "abc/1") returns the
+// JSON object for true.
+func Walk(j Json, path string) Json {
+	for len(path) > 0 {
+		var elem string;
+		if i := strings.Index(path, "/"); i >= 0 {
+			elem = path[0:i];
+			path = path[i+1:len(path)];
+		} else {
+			elem = path;
+			path = "";
+		}
+		switch j.Kind() {
+		case ArrayKind:
+			indx, err := strconv.Atoi(elem);
+			if err != nil {
+				return Null
+			}
+			j = j.Elem(indx);
+		case MapKind:
+			j = j.Get(elem);
+		default:
+			return Null
+		}
+	}
+	return j
+}
+
+// Equal returns whether a and b are indistinguishable JSON objects.
+func Equal(a, b Json) bool {
+	switch {
+	case a == nil && b == nil:
+		return true;
+	case a == nil || b == nil:
+		return false;
+	case a.Kind() != b.Kind():
+		return false;
+	}
+
+	switch a.Kind() {
+	case NullKind:
+		return true;
+	case StringKind:
+		return a.String() == b.String();
+	case NumberKind:
+		return a.Number() == b.Number();
+	case BoolKind:
+		return a.Bool() == b.Bool();
+	case ArrayKind:
+		if a.Len() != b.Len() {
+			return false;
+		}
+		for i := 0; i < a.Len(); i++ {
+			if !Equal(a.Elem(i), b.Elem(i)) {
+				return false;
+			}
+		}
+		return true;
+	case MapKind:
+		m := a.(*_Map).m;
+		if len(m) != len(b.(*_Map).m) {
+			return false;
+		}
+		for k,v := range m {
+			if !Equal(v, b.Get(k)) {
+				return false;
+			}
+		}
+		return true;
+	}
+
+	// invalid kind
+	return false;
+}
+
+
+// Parse builder for JSON objects.
+
+type _JsonBuilder struct {
+	// either writing to *ptr
+	ptr *Json;
+
+	// or to a[i] (can't set ptr = &a[i])
+	a *vector.Vector;
+	i int;
+
+	// or to m[k] (can't set ptr = &m[k])
+	m map[string] Json;
+	k string;
+}
+
+func (b *_JsonBuilder) Put(j Json) {
+	switch {
+	case b.ptr != nil:
+		*b.ptr = j;
+	case b.a != nil:
+		b.a.Set(b.i, j);
+	case b.m != nil:
+		b.m[b.k] = j;
+	}
+}
+
+func (b *_JsonBuilder) Get() Json {
+	switch {
+	case b.ptr != nil:
+		return *b.ptr;
+	case b.a != nil:
+		return b.a.At(b.i).(Json);
+	case b.m != nil:
+		return b.m[b.k];
+	}
+	return nil
+}
+
+func (b *_JsonBuilder) Float64(f float64) {
+	b.Put(&_Number{f, _Null{}})
+}
+
+func (b *_JsonBuilder) Int64(i int64) {
+	b.Float64(float64(i))
+}
+
+func (b *_JsonBuilder) Uint64(i uint64) {
+	b.Float64(float64(i))
+}
+
+func (b *_JsonBuilder) Bool(tf bool) {
+	b.Put(&_Bool{tf, _Null{}})
+}
+
+func (b *_JsonBuilder) Null() {
+	b.Put(Null)
+}
+
+func (b *_JsonBuilder) String(s string) {
+	b.Put(&_String{s, _Null{}})
+}
+
+
+func (b *_JsonBuilder) Array() {
+	b.Put(&_Array{vector.New(0), _Null{}})
+}
+
+func (b *_JsonBuilder) Map() {
+	b.Put(&_Map{make(map[string]Json), _Null{}})
+}
+
+func (b *_JsonBuilder) Elem(i int) Builder {
+	bb := new(_JsonBuilder);
+	bb.a = b.Get().(*_Array).a;
+	bb.i = i;
+	for i >= bb.a.Len() {
+		bb.a.Push(Null)
+	}
+	return bb
+}
+
+func (b *_JsonBuilder) Key(k string) Builder {
+	bb := new(_JsonBuilder);
+	bb.m = b.Get().(*_Map).m;
+	bb.k = k;
+	bb.m[k] = Null;
+	return bb
+}
+
+// StringToJson parses the string s as a JSON-syntax string
+// and returns the generic JSON object representation.
+// On success, StringToJson returns with ok set to true and errtok empty.
+// If StringToJson encounters a syntax error, it returns with
+// ok set to false and errtok set to a fragment of the offending syntax.
+func StringToJson(s string) (json Json, ok bool, errtok string) {
+	var errindx int;
+	var j Json;
+	b := new(_JsonBuilder);
+	b.ptr = &j;
+	ok, errindx, errtok = Parse(s, b);
+	if !ok {
+		return nil, false, errtok
+	}
+	return j, true, ""
+}
+
+// BUG(rsc): StringToJson should return an os.Error instead of a bool.