CSV

A tiny, fast Kotlin Multiplatform library for parsing and building CSV strings. Zero dependencies, explicit API, and predictable behavior.

Platforms: JVM, JS (Browser/Node), iOS, macOS, Linux, Windows

Contributions welcome — please keep the API minimalistic and self-explanatory.

Architecture

Usage

Build CSV

val csv = buildCsv {
    header {
        column("Code")
        column("Name")
    }
    data {
        value("DE")
        value("Deutschland")
    }
    data {
        value("BY")
        value("Belarus")
    }
} as CsvWithHeader

Access columns and values

val code = csv.header.columnByName("Code")!!  // CsvColumn(index=0, name="Code")
val name = csv.header.columnByName("Name")!!  // CsvColumn(index=1, name="Name")

csv.data[0][code]  // "DE"
csv.data[0][name]  // "Deutschland"
csv.data[1][code]  // "BY"
csv.data[1][name]  // "Belarus"

Convert to CSV text

val text = csv.toCsvText()
// "Code,Name\nDE,Deutschland\nBY,Belarus\n"

// With CRLF line endings:
csv.toCsvText(newLine = NewLine.CRLF)

Parse CSV text

// With header row:
val csv = CsvWithHeader.fromCsvText("Code,Name\nDE,Deutschland\n")

// Without header row:
val csv = CsvNoHeader.fromCsvText("DE,Deutschland\nBY,Belarus\n")

Transform data

val transformed = csv.copy(
    data = csv.data.map { row ->
        row.mapValueOf(name) { value ->
            if (value == "Belarus") "Weißrussland" else value
        }
    }
)

Dependencies

In gradle/libs.versions.toml

[versions]
kotlin = "2.3.0"
csv = "1.3"

[libraries]
csv = { module = "de.halfbit:csv", version.ref = "csv" }

[plugins]
kotlin-multiplatform = { id = "org.jetbrains.kotlin.multiplatform", version.ref = "kotlin" }

In shared/build.gradle.kts

plugins {
    alias(libs.plugins.kotlin.multiplatform)
}

kotlin {
    sourceSets {
        commonMain.dependencies {
            implementation(libs.csv)
        }
    }
}

Releasing

1. Bump version in build.gradle.kts of the root project
2. ./gradlew clean build releaseToMavenCentral

License

Copyright 2023-2026 Sergej Shafarenka, www.halfbit.de

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.