argonaut.PrettyParams.scala Maven / Gradle / Ivy
package argonaut
import scala.annotation._
/**
* Parameters for pretty-printing a JSON value.
*
* @author Tony Morris
*
* @param indent The indentation to use if any format strings contain a new line.
* @param lbraceLeft Spaces to insert to left of a left brace.
* @param lbraceRight Spaces to insert to right of a left brace.
* @param rbraceLeft Spaces to insert to left of a right brace.
* @param rbraceRight Spaces to insert to right of a right brace.
* @param lbracketLeft Spaces to insert to left of a left bracket.
* @param lbracketRight Spaces to insert to right of a left bracket.
* @param rbracketLeft Spaces to insert to left of a right bracket.
* @param rbracketRight Spaces to insert to right of a right bracket.
* @param lrbracketsEmpty Spaces to insert for an empty array.
* @param arrayCommaLeft Spaces to insert to left of a comma in an array.
* @param arrayCommaRight Spaces to insert to right of a comma in an array.
* @param objectCommaLeft Spaces to insert to left of a comma in an object.
* @param objectCommaRight Spaces to insert to right of a comma in an object.
* @param colonLeft Spaces to insert to left of a colon.
* @param colonRight Spaces to insert to right of a colon.
* @param preserveOrder Determines if field ordering should be preserved.
* @param dropNullKeys Determines if object fields with values of null are dropped from the output.
*/
case class PrettyParams(
indent: String
, lbraceLeft: String
, lbraceRight: String
, rbraceLeft: String
, rbraceRight: String
, lbracketLeft: String
, lbracketRight: String
, rbracketLeft: String
, rbracketRight: String
, lrbracketsEmpty: String
, arrayCommaLeft: String
, arrayCommaRight: String
, objectCommaLeft: String
, objectCommaRight: String
, colonLeft: String
, colonRight: String
, preserveOrder: Boolean
, dropNullKeys: Boolean
) {
private[this] final val openBraceText = "{"
private[this] final val closeBraceText = "}"
private[this] final val openArrayText = "["
private[this] final val closeArrayText = "]"
private[this] final val commaText = ","
private[this] final val colonText = ":"
private[this] final val nullText = "null"
private[this] final val trueText = "true"
private[this] final val falseText = "false"
private[this] final val stringEnclosureText = "\""
private[this] val _lbraceLeft = addIndentation(lbraceLeft)
private[this] val _lbraceRight = addIndentation(lbraceRight)
private[this] val _rbraceLeft = addIndentation(rbraceLeft)
private[this] val _rbraceRight = addIndentation(rbraceRight)
private[this] val _lbracketLeft = addIndentation(lbracketLeft)
private[this] val _lbracketRight = addIndentation(lbracketRight)
private[this] val _rbracketLeft = addIndentation(rbracketLeft)
private[this] val _rbracketRight = addIndentation(rbracketRight)
private[this] val _lrbracketsEmpty = addIndentation(lrbracketsEmpty)
private[this] val _arrayCommaLeft = addIndentation(arrayCommaLeft)
private[this] val _arrayCommaRight = addIndentation(arrayCommaRight)
private[this] val _objectCommaLeft = addIndentation(objectCommaLeft)
private[this] val _objectCommaRight = addIndentation(objectCommaRight)
private[this] val _colonLeft = addIndentation(colonLeft)
private[this] val _colonRight = addIndentation(colonRight)
private[this] def addIndentation(s: String): Int => String = {
val lastNewLineIndex = s.lastIndexOf("\n")
if (lastNewLineIndex < 0) {
_ => s
} else {
val afterLastNewLineIndex = lastNewLineIndex + 1
val start = s.substring(0, afterLastNewLineIndex)
val end = s.substring(afterLastNewLineIndex)
n => start + indent * n + end
}
}
// TODO: Vector based memoisation.
private[this] final val lbraceMemo = PrettyParams.vectorMemo{depth => _lbraceLeft(depth) + openBraceText + _lbraceRight(depth + 1)}
private[this] final val rbraceMemo = PrettyParams.vectorMemo{depth => _rbraceLeft(depth) + closeBraceText + _rbraceRight(depth + 1)}
private[this] final val lbracketMemo = PrettyParams.vectorMemo{depth => _lbracketLeft(depth) + openArrayText + _lbracketRight(depth + 1)}
private[this] final val rbracketMemo = PrettyParams.vectorMemo{depth => _rbracketLeft(depth) + closeArrayText + _rbracketRight(depth)}
private[this] final val lrbracketsEmptyMemo = PrettyParams.vectorMemo{depth => openArrayText + _lrbracketsEmpty(depth) + closeArrayText}
private[this] final val arrayCommaMemo = PrettyParams.vectorMemo{depth => _arrayCommaLeft(depth + 1) + commaText + _arrayCommaRight(depth + 1)}
private[this] final val objectCommaMemo = PrettyParams.vectorMemo{depth => _objectCommaLeft(depth + 1) + commaText + _objectCommaRight(depth + 1)}
private[this] final val colonMemo = PrettyParams.vectorMemo{depth => _colonLeft(depth + 1) + colonText + _colonRight(depth + 1)}
/**
* Returns a string representation of a pretty-printed JSON value.
*/
final def pretty(j: Json): String = {
import Json._
import StringEscaping._
def appendJsonString(builder: StringBuilder, jsonString: String): StringBuilder = {
for (ch <- jsonString) {
if (isNormalChar(ch)) {
builder.append(ch)
} else {
builder.append(escape(ch))
}
}
builder
}
def encloseJsonString(builder: StringBuilder, jsonString: JsonString): StringBuilder = {
appendJsonString(builder.append(stringEnclosureText), jsonString).append(stringEnclosureText)
}
def trav(builder: StringBuilder, depth: Int, k: Json): StringBuilder = {
def lbrace(builder: StringBuilder): StringBuilder = {
builder.append(lbraceMemo(depth))
}
def rbrace(builder: StringBuilder): StringBuilder = {
builder.append(rbraceMemo(depth))
}
def lbracket(builder: StringBuilder): StringBuilder = {
builder.append(lbracketMemo(depth))
}
def rbracket(builder: StringBuilder): StringBuilder = {
builder.append(rbracketMemo(depth))
}
def lrbracketsEmpty(builder: StringBuilder): StringBuilder = {
builder.append(lrbracketsEmptyMemo(depth))
}
def arrayComma(builder: StringBuilder): StringBuilder = {
builder.append(arrayCommaMemo(depth))
}
def objectComma(builder: StringBuilder): StringBuilder = {
builder.append(objectCommaMemo(depth))
}
def colon(builder: StringBuilder): StringBuilder = {
builder.append(colonMemo(depth))
}
k.fold[StringBuilder](
builder.append(nullText)
, bool => builder.append(if (bool) trueText else falseText)
, n => n match {
case JsonLong(x) => builder.append(x.toString)
case JsonDecimal(x) => builder.append(x)
case JsonBigDecimal(x) => builder.append(x.toString)
}
, s => encloseJsonString(builder, s)
, e => if (e.isEmpty) {
lrbracketsEmpty(builder)
} else {
rbracket(e.foldLeft((true, lbracket(builder))){case ((firstElement, builder), subElement) =>
val withComma = if (firstElement) builder else arrayComma(builder)
val updatedBuilder = trav(withComma, depth + 1, subElement)
(false, updatedBuilder)
}._2)
}
, o => {
rbrace((if (preserveOrder) o.toList else o.toMap).foldLeft((true, lbrace(builder))){case ((firstElement, builder), (key, value)) =>
val ignoreKey = dropNullKeys && value.isNull
if (ignoreKey) {
(firstElement, builder)
} else {
val withComma = if (firstElement) builder else objectComma(builder)
(false, trav(colon(encloseJsonString(withComma, key)), depth + 1, value))
}
}._2)
}
)
}
trav(new StringBuilder(), 0, j).toString()
}
/**
* Returns a `Vector[Char]` representation of a pretty-printed JSON value.
*/
final def lpretty(j: Json): Vector[Char] = Vector.empty[Char] ++ pretty(j)
}
object StringEscaping {
final def escape(c: Char): String = (c: @switch) match {
case '\\' => "\\\\"
case '"' => "\\\""
case '\b' => "\\b"
case '\f' => "\\f"
case '\n' => "\\n"
case '\r' => "\\r"
case '\t' => "\\t"
case possibleUnicode => if (Character.isISOControl(possibleUnicode)) "\\u%04x".format(possibleUnicode.toInt) else possibleUnicode.toString
}
final val isNormalChar: Char => Boolean = char => (char: @switch) match {
case '\\' => false
case '"' => false
case '\b' => false
case '\f' => false
case '\n' => false
case '\r' => false
case '\t' => false
case possibleUnicode => !Character.isISOControl(possibleUnicode)
}
}
object PrettyParams extends PrettyParamss {
def vectorMemo(f: Int => String): Int => String = {
var vector: Vector[String] = Vector.empty
(i: Int) => {
if (i >= 0) {
val captured = vector
if (captured.size <= i) {
val tabulated = Vector.tabulate(i + 1)(f)
val result = tabulated(i)
if (vector.size < tabulated.size) {
vector = tabulated
}
result
} else {
captured(i)
}
} else {
""
}
}
}
}
trait PrettyParamss {
/**
* A pretty-printer configuration that inserts no spaces.
*/
final val nospace: PrettyParams =
PrettyParams(
indent = ""
, lbraceLeft = ""
, lbraceRight = ""
, rbraceLeft = ""
, rbraceRight = ""
, lbracketLeft = ""
, lbracketRight = ""
, rbracketLeft = ""
, rbracketRight = ""
, lrbracketsEmpty = ""
, arrayCommaLeft = ""
, arrayCommaRight = ""
, objectCommaLeft = ""
, objectCommaRight = ""
, colonLeft = ""
, colonRight = ""
, preserveOrder = false
, dropNullKeys = false
)
/**
* A pretty-printer configuration that indents by the given spaces.
*/
final def pretty(indent: String): PrettyParams =
PrettyParams(
indent = indent
, lbraceLeft = ""
, lbraceRight = "\n"
, rbraceLeft = "\n"
, rbraceRight = ""
, lbracketLeft = ""
, lbracketRight = "\n"
, rbracketLeft = "\n"
, rbracketRight = ""
, lrbracketsEmpty = ""
, arrayCommaLeft = ""
, arrayCommaRight = "\n"
, objectCommaLeft = ""
, objectCommaRight = "\n"
, colonLeft = " "
, colonRight = " "
, preserveOrder = false
, dropNullKeys = false
)
/**
* A pretty-printer configuration that indents by two spaces.
*/
final val spaces2: PrettyParams = pretty(" ")
/**
* A pretty-printer configuration that indents by four spaces.
*/
final val spaces4: PrettyParams = pretty(" ")
}
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