REPLesent

represent verb 0. depict, portray, render, delineate, show, illustrate. 0. symbolize, stand for, personify, typify, embody. 0. point out, state, present, put forward.

REPLesent is a neat little powerful tool to build presentations using the Scala REPL.

Conceptualized and originally implemented while waiting almost two hours for my plane to be de-iced, it was introduced during the Northeast Scala Symposium 2015 in Boston.

While clearly not a Powerpoint Keynote replacement, REPLesent is a good option for training sessions and technical talks featuring live coding. Its old-school looks were considered very cool by many conference attendants.

Features

• Easy to write slides: a simple plain text file with minimal markup
• The full arsenal of navigation options: next, previous, first, last, jump to
• Builds (incremental slides)
• Slide number / total
• Text alignment: left, right, centered, flushed
• ANSI colors
• Horizontal rulers (thanks, @daviscabral)
• Syntax highlighting
• Run code straight from slides directly in the REPL with a single keystroke. No other presentation tool can do that for you!
• And the #1 requested feature: emoji! :-) I mean, 😄

Quick Tour

Getting Started

REPLesent is distributed as a single .scala file and has no dependencies.

REPLesent was designed to be used only in conjunction with the Scala REPL. It is not meant to be compiled as a standalone application (build.sbt is only for running the unit tests).

We recommend you install and use the full Scala distribution (the scala command) instead of just the sbt console. Scala 2.11.4 or later and JDK 7 or later are the preferred versions. If you are using Windows, you need to run scala in ANSICON or another console that supports ANSI escape codes. REPLesent will not render correctly in Windows' standard cmd console.

To get started, download and save to the same folder the files REPLesent.scala and REPLesent.txt. The file emoji.txt is optional, only needed to enable emoji support.

First, create an alias:

alias REPLesent='scala -Dscala.color -language:_ -nowarn -i REPLesent.scala'

Open the REPL and enter the two statements below:

$ REPLesent
Loading REPLesent.scala...
defined class REPLesent

Welcome to Scala version 2.11.5 (Java HotSpot(TM) 64-Bit Server VM, Java 1.8.0_31).
Type in expressions to have them evaluated.
Type :help for more information.

scala> val replesent = REPLesent(80, 25, intp=$intp)
replesent: REPLesent = REPLesent(80,25,REPLesent.txt)

scala> import replesent._
import replesent._

Do not forget to replace 80, 25 with the actual size of your terminal window. The intp=$intp incantation is required to hook onto the REPL to run slide code.

Once all is done, type f, press ENTER, and follow the on-screen instructions.

Experimental screen size auto-detection: For Unix-like systems, including Mac OS X and Linux, you can omit the screen size. Does not work for Microsoft Windows systems.

Quick Reference Guide

Initialization options

Parameter	Type	Description	Default
width	Int	Terminal width in columns	0 (Unix: autodetect, Windows: 80)
height	Int	Terminal height in rows	0 (Unix: autodetect, Windows: 25)
input	String	The path to the presentation file	"REPLesent.txt"
slideCounter	Boolean	Whether to show the slide number	false
slideTotal	Boolean	Whether to show the total number of slides	false
intp		A hook to the Scala REPL	No default, use magic value $intp

Navigation commands

Command	Shortcut	Symbolic alias	Description
next	n	>	Go to next build/slide
previous	p	<	Go back to previous build/slide
redraw	z		Redraw the current build/slide
Next	N	>>	Go to next slide
Previous	P	<<	Go back to previous slide
i next	i n		Advance i slides
i previous	i p		Go back i slides
i go	i g		Go to slide i
first	f	`	<`
last	l	`>	`
Last	L	`>>	`
run	r	!!	Execute code that appears on slide
blank	b		Blank screen
help	h	?	This help message

Separators and delimiters

Separator	Description
---	Separates slides
--	Separates builds
```	Delineates Scala code

Text alignment

Command	Description
<<	Left-flushed text
<	Left-aligned text
`	`
>	Right-aligned text
>>	Right-flushed text

A space separating the alignment command from the text is mandatory.

ANSI colors

Escape code	Result
\x	Foreground color, where x is one of: red, green, blue, cyan, magenta, yellow, black, white
\X	Background color, where capital X is one of the same as above
\*	Bold
\_	Underscore
\!	Reverse colors
\s	Resets to normal

Horizontal rulers

Command	Description
/	A ruler across the slide length
//	A ruler across the entire screen width

An optional pattern may be specified immediately following the forward slash. Unicode characters and ANSI color escapes (as above) are supported.

Emoji

To enable emoji support, you will need a copy of the emoji.txt file.

Almost all shortcuts listed by the Emoji cheat sheet are supported. You can look at emoji.txt for the definitive list of supported emoji.

Emojis can be combined with horizontal rulers and, depending on your system fonts, ANSI colors, too.

Emoji has only be tested on Mac OS X Terminal.app, YMMV.

Thanks

• Davis Z. Cabral for implementing horizontal ruler support.

I don't care if it is used, I just want it to be useful

License

Copyright 2015 Marconi Lanna

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.