Replicant

Replicant is a set of utilities intended to ease inspection of objects in the scala REPL. This is an 0.1 release, so it's currently

• Barely tested
• Light on functionality
• Also light on useability

If you have bugs/requests/etc. please let me know

Usage

Dependencies

Replicant requires scala 2.8.1 (http://www.scala-lang.org/) and SBT (http://code.google.com/p/simple-build-tool/) if you want to build from source.

Building

After cloning the project, run "sbt update package". This should create a jar file in target.

Using it in the REPL

Once you have the jar, just add it to your scala classpath, e.g.

scala -cp replicant-0.1-SNAPSHOT.jar

Replicant provides a set of implicits in org.mccv.replicant.Replicant that you'll likely want to use. Just type

import org.mccv.replicant.Replicant._

To make them available

Features

The Basics

There are three high level commands available on any object.

• m() returns an inspector for all methods defined on an object, e.g.

scala> "s".m

res1: org.mccv.replicant.Methods =
=== methods from java.lang.String===


equals(java.lang.Object)
toString()
hashCode()

• c() returns an inspector for all constructors defined on an object, e.g.

scala> "s".c
res2: org.mccv.replicant.Constructors =
=== methods from java.lang.String===


java.lang.String()
java.lang.String(java.lang.String)
java.lang.String(char[])
java.lang.String(char[], int, int)
java.lang.String(int[], int, int)
java.lang.String(byte[], int, int, int)

• f() returns an inspector for all fields defined on an object, e.g.

res3: org.mccv.replicant.Fields =
=== fields from java.lang.String===
F  -           value
F  -           offset
F  -           count


hash
F  -  S        serialVersionUID

This is partial output. In the case of scala objects you may get a string hundreds (and hundreds) of lines long. Each method/field/constructor is displayed with a string representation of its modifiers, its name, and parameter types (for fields and constructors).

The complete list of possible modifier columns is...

AFIN-*+Ss|TV

Which correspond to abstract, final, interface, native, private, protected, public, static, strict, synchronized, transient and volatile.

Filters

Some objects have a ton of methods. Each replicant inspector takes a filter to restrict the set of displayed items. The default filter just passes everything through, but it's simple to apply additional filters. The following line finds all public methods that contain the term "index"

scala> "s".m.pub / "index"
res5: org.mccv.replicant.Methods =
=== methods from java.lang.String===


indexOf(int)
indexOf(java.lang.String)
indexOf(java.lang.String, int)
indexOf(int, int)
lastIndexOf(java.lang.String, int)
lastIndexOf(int)
lastIndexOf(int, int)
lastIndexOf(java.lang.String)

If you want to further restrict this to just methods that take a String argument, you can do that with

scala> "s".m.pub./("index").takes("String")
res6: org.mccv.replicant.Methods =
=== methods from java.lang.String===


indexOf(java.lang.String)
indexOf(java.lang.String, int)
lastIndexOf(java.lang.String, int)
lastIndexOf(java.lang.String)

Have a look at org.mccv.replicant.Replicant.scala for more predefined filters. You can also define your own like so:

scala> "s".m.filter(x => x.getName.endsWith("f"))
res9: org.mccv.replicant.Methods =
=== methods from java.lang.String===


indexOf(int)
indexOf(java.lang.String)
S        indexOf(char[], int, int, char[], int, int, int)
indexOf(java.lang.String, int)