Tsuji 通詞

In one example

A message family groups messages under a key prefix. Its arguments are named and typed, and a macro in the library checks the templates when the code compiles:

import java.time.LocalDate
import dev.taihei.tsuji.*
import dev.taihei.tsuji.Language.*

object Orders extends MessageFamily("order"):
  val cancelled = message("Your order was cancelled", Dutch -> "Uw bestelling werd geannuleerd")
  val shipped   = message[(count: Int, on: LocalDate)](
    ".match {$count :plural} when one {One item shipped on {$on :date dateStyle=long}} " +
      "when * {{$count} items shipped on {$on :date dateStyle=long}}",
    Dutch -> (".match {$count :plural} when one {Eén artikel verzonden op {$on :date dateStyle=long}} " +
      "when * {{$count} artikels verzonden op {$on :date dateStyle=long}}"),
  )

given Catalogues = Catalogues(Seq(Orders))

val shipped = Orders.shipped(count = 3, on = LocalDate.of(2026, 10, 23))
shipped.localize(English)          // 3 items shipped on October 23, 2026
shipped.localize(Dutch)            // 3 artikels verzonden op 23 oktober 2026
shipped.localize(Language("de"))   // 3 items shipped on 23. Oktober 2026

There is no German translation, so the last line falls back to the English template, and formats the date in German.

Install

Taihei Tsuji needs Scala 3.9 or later, and on the JVM Java 21 or later: 5.0.0 uses a JDK method from Java 19, and on Java 17 formatting a number or a date for Dutch (nl) fails. It is published for the JVM (taihei-tsuji_3) and for Scala.js (taihei-tsuji_sjs1_3); the two have the same API.

// Mill
mvn"dev.taihei::taihei-tsuji:5.0.0"          // JVM
mvn"dev.taihei::taihei-tsuji::5.0.0"         // Scala.js

// sbt
libraryDependencies += "dev.taihei" %% "taihei-tsuji" % "5.0.0"    // JVM
libraryDependencies += "dev.taihei" %%% "taihei-tsuji" % "5.0.0"   // Scala.js, and cross-built projects

// scala-cli
//> using dep dev.taihei::taihei-tsuji:5.0.0                        // JVM
//> using dep dev.taihei::taihei-tsuji::5.0.0                       // with //> using platform scala-js

On the JVM, numbers and dates are formatted through java.text and java.time; on Scala.js through the browser's Intl API, with java.time from scala-java-time. The library depends on zio-json for its JSON codecs, and on nothing for the user interface or for effects.

The tools module

taihei-tsuji-tools, for the JVM only, holds one program, ExportCatalogues. It finds the message families on your application's classpath and writes one catalogue file per language: the source language for translators, and the other languages for a browser application to load. It is an ordinary program you run, not a build plugin, so it belongs on a run classpath, not in your application:

// Mill
def runMvnDeps = Seq(mvn"dev.taihei::taihei-tsuji-tools:5.0.0")

// sbt
libraryDependencies += "dev.taihei" %% "taihei-tsuji-tools" % "5.0.0"

See Exporting catalogues in the guide for how to run it.

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