commonMain.jetbrains.datalore.base.json.JsonSupport.kt Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of lets-plot-common Show documentation

Lets-Plot JVM package without rendering part

There is a newer version: 4.5.3-alpha1

/*
 * Copyright (c) 2019. JetBrains s.r.o.
 * Use of this source code is governed by the MIT license that can be found in the LICENSE file.
 */

package jetbrains.datalore.base.json

import kotlin.native.concurrent.SharedImmutable

object JsonSupport {
    fun parseJson(jsonString: String): MutableMap {
        @Suppress("UNCHECKED_CAST")
        return JsonParser(jsonString).parseJson() as MutableMap
    }
    fun formatJson(o: Any): String {
        return JsonFormatter().formatJson(o)
    }
}


// Useful resources:
// https://www.ietf.org/rfc/rfc4627.txt
// https://github.com/nst/JSONTestSuite

internal enum class Token {
    LEFT_BRACE,
    RIGHT_BRACE,
    LEFT_BRACKET,
    RIGHT_BRACKET,
    COMMA,
    COLON,
    STRING,
    NUMBER,
    TRUE,
    FALSE,
    NULL,
}

@SharedImmutable
internal val SPECIAL_CHARS = mapOf(
    '"' to '"',
    '\\' to '\\',
    '/' to '/',
    'b' to '\b',
    'f' to '\u000C',
    'n' to '\n',
    'r' to '\r',
    't' to '\t'
)
@SharedImmutable
private val CONTROL_CHARS = (0 until 0x20).map(Int::toChar).toSet()

fun String.escape(): String {
    var output: StringBuilder? = null
    var i = 0

    fun appendOutput(str: String) {
        output = (output ?: StringBuilder(substring(0, i))).append(str)
    }

    while(i < length) {
        when(val ch = get(i)) {
            '\\' -> appendOutput("""\\""")
            '"' -> appendOutput("""\"""")
            '\n' -> appendOutput("""\n""")
            '\r' -> appendOutput("""\r""")
            '\t' -> appendOutput("""\t""")
            in CONTROL_CHARS -> appendOutput("""\u${ch.code.toString(16).padStart(4, '0')}""")
            else -> output?.append(ch)
        }
        i++
    }
    return output?.toString() ?: this
}

fun String.unescape(): String {
    var output: StringBuilder? = null
    val start = 1
    val end = length - 1

    var i = start
    while(i < end) {
        val ch = get(i)
        if (ch == '\\') {
            output = output ?: StringBuilder(substring(start, i))
            when(val escapedChar = get(++i)) {
                in SPECIAL_CHARS -> SPECIAL_CHARS[escapedChar].also { i++ }
                'u' -> substring(i + 1, i + 5).toInt(16).toChar().also { i += 5 }
                else -> throw JsonParser.JsonException("Invalid escape character: ${escapedChar}")
            }.let { output.append(it) }
        } else {
            output?.append(ch); i++
        }
    }
    return output?.toString() ?: substring(start, end)
}