What's LTSV? ltsv.org has all the details, but to get you started:

With the LTSV format, you can parse each line by spliting with TAB (like original TSV format) easily, and extend any fields with unique labels in no particular order.

LTSV-logger is a performant and DRY LTSV logger wrapping SLF4J to provide nice LTSV logging for Scala. No need to wrap your LTSV pairs in Seqs or pay at runtime for call-by-name argument access.

It's convenient, because you can simply call log methods without checking whether the respective log level is enabled:

LTSVLogger.debug(e, "message" -> s"Some $expensive message!")

It's performant, because thanks to Scala macros the check-enabled-idiom is applied, just like writing this more involved code:

if (logger.isDebugEnabled) LTSVLogger.debug(e, "message" -> s"Some $expensive message!")

Sounds similar to Scala Logging? It's not a coincidence ;)

Add the following to your build.sbt

// in your build.sbt

libraryDependencies ++= Seq(
    "com.beachape" %% "ltsv-logger" % "0.1.0",
    "ch.qos.logback" % "logback-classic" % "1.1.2", // or any SLF4J compatible log lib you want to use
)

If the above does not work because it cannot be resolved, its likely because it hasn't been synced to Maven central yet. In that case, download a SNAPSHOT release of the same version by adding this to build.sbt

resolvers += "Sonatype OSS Snapshots" at "https://oss.sonatype.org/content/repositories/snapshots"

libraryDependencies ++= Seq(
    "com.beachape" %% "ltsv-logger" % "0.1.0-SNAPSHOT",
    "ch.qos.logback" % "logback-classic" % "1.1.2", // or any slf4j compatible log lib you want to use
)

import com.beachape.logging.LTSVLogger

LTSVLogger.info("hello" -> 3)
LTSVLogger.warn(new IllegalArgumentException, "hello" -> 3)

/**
  All of the above will act "lazily" at runtime and not be computed/referenced if the respective
  levels are not enabled.

  If varargs call-by-name was supported in Scala, the above would be implemented as
  something like

  {{{ def warn(pairs: => (String, Any) *): Unit = if (logger.isWarnEnabled) logger.warn(toLtsv(pairs)) }}}
**/

/*
  Alternatively, if you want to log a generic object, created a LTSVable[A] typed to your object.

  This will also still be lazy.
*/

case class Request(method: String, path: String)

implicit val reqLTSVable = new LTSVable[Request] {
  def toPairs(o: Request): Seq[(String, Any)] = {
    Seq("method" -> o.method, "path" -> o.path)
  }
}

LTSVLogger.info(Request("GET", "/"), "hello" -> 3)

• SLF4J
• LTSV4S

• Doesn't implement the entire interface for SLF4J (yet), but should provide you with enough to do most of your logging chores.

The MIT License (MIT)

Copyright (c) 2014 by Lloyd Chan

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.