spray.json.PrettyPrinter.scala Maven / Gradle / Ivy
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/*
* Copyright (C) 2009-2011 Mathias Doenitz
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package spray.json
import java.lang.StringBuilder
import annotation.tailrec
/**
* A JsonPrinter that produces a nicely readable JSON source.
*/
trait PrettyPrinter extends JsonPrinter {
val Indent = 2
def print(x: JsValue, sb: StringBuilder) {
print(x, sb, 0)
}
protected def print(x: JsValue, sb: StringBuilder, indent: Int) {
x match {
case JsObject(x) => printObject(x, sb, indent)
case JsArray(x) => printArray(x, sb, indent)
case _ => printLeaf(x, sb)
}
}
protected def printObject(members: Map[String, JsValue], sb: StringBuilder, indent: Int) {
sb.append("{\n")
printSeq(members, sb.append(",\n")) { m =>
printIndent(sb, indent + Indent)
printString(m._1, sb)
sb.append(": ")
print(m._2, sb, indent + Indent)
}
sb.append('\n')
printIndent(sb, indent)
sb.append("}")
}
protected def printArray(elements: Seq[JsValue], sb: StringBuilder, indent: Int) {
sb.append('[')
printSeq(elements, sb.append(", "))(print(_, sb, indent))
sb.append(']')
}
protected def printIndent(sb: StringBuilder, indent: Int) {
@tailrec def rec(indent: Int): Unit =
if (indent > 0) {
sb.append(' ')
rec(indent - 1)
}
rec(indent)
}
}
object PrettyPrinter extends PrettyPrinter