Fix compact/indent

compact.go

@@ -0,0 +1,43 @@
+package json
+
+import (
+	"bytes"
+)
+
+func compact(dst *bytes.Buffer, src []byte) error {
+	length := len(src)
+	for cursor := 0; cursor < length; cursor++ {
+		c := src[cursor]
+		switch c {
+		case ' ', '\t', '\n', '\r':
+			continue
+		case '"':
+			if err := dst.WriteByte(c); err != nil {
+				return err
+			}
+			for {
+				cursor++
+				if err := dst.WriteByte(src[cursor]); err != nil {
+					return err
+				}
+				switch src[cursor] {
+				case '\\':
+					cursor++
+					if err := dst.WriteByte(src[cursor]); err != nil {
+						return err
+					}
+				case '"':
+					goto LOOP_END
+				case nul:
+					return errUnexpectedEndOfJSON("string", int64(length))
+				}
+			}
+		default:
+			if err := dst.WriteByte(c); err != nil {
+				return err
+			}
+		}
+	LOOP_END:
+	}
+	return nil
+}

indent.go

@@ -0,0 +1,106 @@
+package json
+
+import "bytes"
+
+func encodeWithIndent(dst *bytes.Buffer, src []byte, prefix, indentStr string) error {
+	length := int64(len(src))
+	indentNum := 0
+	indentBytes := []byte(indentStr)
+	for cursor := int64(0); cursor < length; cursor++ {
+		c := src[cursor]
+		switch c {
+		case ' ', '\t', '\n', '\r':
+			continue
+		case '"':
+			if err := dst.WriteByte(c); err != nil {
+				return err
+			}
+			for {
+				cursor++
+				if err := dst.WriteByte(src[cursor]); err != nil {
+					return err
+				}
+				switch src[cursor] {
+				case '\\':
+					cursor++
+					if err := dst.WriteByte(src[cursor]); err != nil {
+						return err
+					}
+				case '"':
+					goto LOOP_END
+				case nul:
+					return errUnexpectedEndOfJSON("string", int64(length))
+				}
+			}
+		case '{':
+			if cursor+1 < length && src[cursor+1] == '}' {
+				if _, err := dst.Write([]byte{'{', '}'}); err != nil {
+					return err
+				}
+				cursor++
+			} else {
+				indentNum++
+				b := []byte{c, '\n'}
+				b = append(b, prefix...)
+				b = append(b, bytes.Repeat(indentBytes, indentNum)...)
+				if _, err := dst.Write(b); err != nil {
+					return err
+				}
+			}
+		case '}':
+			indentNum--
+			if indentNum < 0 {
+				return errInvalidCharacter('}', "}", cursor)
+			}
+			b := []byte{'\n', c}
+			b = append(b, prefix...)
+			b = append(b, bytes.Repeat(indentBytes, indentNum)...)
+			if _, err := dst.Write(b); err != nil {
+				return err
+			}
+		case '[':
+			if cursor+1 < length && src[cursor+1] == ']' {
+				if _, err := dst.Write([]byte{'[', ']'}); err != nil {
+					return err
+				}
+				cursor++
+			} else {
+				indentNum++
+				b := []byte{c, '\n'}
+				b = append(b, prefix...)
+				b = append(b, bytes.Repeat(indentBytes, indentNum)...)
+				if _, err := dst.Write(b); err != nil {
+					return err
+				}
+			}
+		case ']':
+			indentNum--
+			if indentNum < 0 {
+				return errInvalidCharacter(']', "]", cursor)
+			}
+			b := []byte{'\n', c}
+			b = append(b, prefix...)
+			b = append(b, bytes.Repeat(indentBytes, indentNum)...)
+			if _, err := dst.Write(b); err != nil {
+				return err
+			}
+		case ':':
+			if _, err := dst.Write([]byte{':', ' '}); err != nil {
+				return err
+			}
+		case ',':
+			b := []byte{',', '\n'}
+			b = append(b, prefix...)
+			b = append(b, bytes.Repeat(indentBytes, indentNum)...)
+			if _, err := dst.Write(b); err != nil {
+				return err
+			}
+		default:
+			if err := dst.WriteByte(c); err != nil {
+				return err
+			}
+		}
+	LOOP_END:
+	}
+	return nil
+}

json.go

@@ -325,15 +325,7 @@ func (m *RawMessage) UnmarshalJSON(data []byte) error {
 // Compact appends to dst the JSON-encoded src with
 // insignificant space characters elided.
 func Compact(dst *bytes.Buffer, src []byte) error {
-	var v interface{}
-	dec := NewDecoder(bytes.NewBuffer(src))
-	dec.UseNumber()
-	if err := dec.Decode(&v); err != nil {
-		return err
-	}
-	enc := NewEncoder(dst)
-	enc.SetEscapeHTML(false)
-	return enc.Encode(v)
+	return compact(dst, src)
 }
 
 // Indent appends to dst an indented form of the JSON-encoded src.
@@ -348,16 +340,7 @@ func Compact(dst *bytes.Buffer, src []byte) error {
 // For example, if src has no trailing spaces, neither will dst;
 // if src ends in a trailing newline, so will dst.
 func Indent(dst *bytes.Buffer, src []byte, prefix, indent string) error {
-	var v interface{}
-	dec := NewDecoder(bytes.NewBuffer(src))
-	dec.UseNumber()
-	if err := dec.Decode(&v); err != nil {
-		return err
-	}
-	enc := NewEncoder(dst)
-	enc.SetEscapeHTML(false)
-	enc.SetIndent(prefix, indent)
-	return enc.Encode(v)
+	return encodeWithIndent(dst, src, prefix, indent)
 }
 
 // HTMLEscape appends to dst the JSON-encoded src with <, >, &, U+2028 and U+2029