ern0 / rsg

random sentence generator

RSG - Random Sentence Generator

Foreword

Mission

Random text generation is fun. I've created this engine for committed funmakers, including myself.

The engine is written in PHP, and supports the use of HTML. The database script language is not JSON, nor XML, but plain text, similar to Makefile.

It was a design guideline that the engine should be suitable for Hungarian language, because it's so complicated, that other languages will also work then.

You are the author

If you want to write a good program, a good compiler is only a tool.

Also, this RSG engine is only a tool. Good quality result requires lot of quality content.

RSG is not an easy genre.

Integrator's manual

Add to your program

Load text, then pass parsed nodes to the renderer:

$text = new Text("rsg_kontent.txt");
$text->load();
$renderer = new Renderer(null, $text->nodes);
$renderer->render("@main");

If you want to print the result later, you can change the last line to these:

$renderer->isDirectRendering = false;
$result = $renderer->render("@main");

Tests

If you want to understand how the program works, you should first study the tests. The coverage is not 100%, but there're tests for neuralgic points.

Also, tests can be useful when you modify the program, and want to see whether something broke.

You can run tests by starting the script named t, which calls test/test.php. The result should be like:

[okay] - RsgSuite - cases: 13, passed: 13, failed: 0, asserts: 146, passed: 146, failed: 0

Web server requirements

I've tested it with Apache2.

The program requires PHP7, with mbstring module installed. Probably it's preinstalled, if not, to install it on a Debian system, run this command:

sudo apt install php-mbstring

Dev server

You might start a PHP dev server for development, including RSG script writing, by starting the script named a, which simply runs php -S localhost:8080.

Then you can point your browser to localhost:8080, and select RSG script from the menu.

RSG author's manual

This chapter contains tutorials, each introduces some features, from easy to difficult ones. You will able to write funny scripts after the first lession, but it's worth to go on and use advanced features.

You can found all the examples in the repository, and also you can try them at: http://linkbroker.hu/stuff/rsg/

Tutor-1: Nodes and tags

Let's jump into the script:

node id=main
	My favorite color is #color

node tag=color
	black
node tag=color
	blue
node tag=color
	gray
node tag=shape
	circle

All the text data is organized into nodes. A node may have properties, like id or tag. Node definitions are starting at the first column, lines starting with any whitespace (space, tab) belongs to the node.

When the engine starts, it picks the main node, which's id property is main, and renders it.

The engine renders words and HTML tags without any change. When the engine reach a reference, it selects a node from the set specified by the reference, then renders the node instead of the reference.

The most simple form of a reference is the tag selector: a hashmark followed by a tag value. The engine will filter for all nodes, which has tag property with the specified value, and will randomly select one of them.

Let's run it several times:

• My favorite color is gray
• My favorite color is blue
• My favorite color is black
• My favorite color is blue
• My favorite color is black
• My favorite color is gray
• My favorite color is gray
• My favorite color is black

Note, that circle will be not selected, because its tag is shape.

Tutor-2: Unique selections

Once a node is selected, it will be not selected any more.

node id=main
	Do you now the song #color and #color?

node tag=color
	Black
node tag=color
	Blue
node tag=color
	Red
node tag=color
	Green
node tag=color
	Yellow
node tag=color
	Purple
node tag=color
	White

Run this script more times:

• Do you now the song Purple and White?
• Do you now the song Purple and Green?
• Do you now the song Green and White?
• Do you now the song White and Purple?
• Do you now the song Black and Purple?
• Do you now the song Blue and Purple?
• Do you now the song Red and Black?
• Do you now the song Yellow and White?

As you can see, there are only different colors in song titles.

Tutor-3: Going deeper

This is the feature, which overshines simple random sentence generators, which simply selects three items from three set of words.

Generate a funny animal, describing its size, color and species, but let's tweak it: sometimes don't tell its size or color, and sometimes add shade for the color!

node id=main
	Kitty is a #kind. I love Kitty.
		
node tag=kind
	#size #shade #color #species
node tag=kind
	#size #color #species
node tag=kind
	#shade #color #species
node tag=kind
	#color #species
node tag=kind
	#size #species

node tag=size
	tiny
node tag=size
	small
node tag=size
	big
node tag=size
	huge

node tag=shade
	light
node tag=shade
	dark

node tag=color
	blue
node tag=color
	red
node tag=color
	green
node tag=color
	yellow
node tag=color
	purple
node tag=color
	orange
node tag=color
	turquoise

node tag=species
	dog
node tag=species
	cat
node tag=species
	elephant
node tag=species
	snail

The main node selects which properties of the animal will be specified, the kind nodes are the availalbe variations. The result is:

• Kitty is a huge light purple cat.
• Kitty is a light red cat.
• Kitty is a red cat.
• Kitty is a blue dog.
• Kitty is a huge elephant.
• Kitty is a dark orange cat.
• Kitty is a huge turquoise cat.
• Kitty is a light blue dog.

Tutor-4: Random errors

The bad news is that errors may pop up randomly, according to actual selections. The good new is that there are only one error type, which can happen for two reasons.

node id=main
	Error #blahblah #maybe

node tag=maybe
	#not_enough
node tag=maybe
	#not_enough #not_enough
	
node tag=not_enough
	black

If you make a typo in a reference, or just forget to create a set for it, the error is guaranteed. This is the better case, anyway.

The worst case is, when you have a set, which might be referenced more times than the number of elements, but not always. Be careful!

• Error ERROR(tag=blahblah) black ERROR(tag=not_enough)
• Error ERROR(tag=blahblah) black

The engine will render an error message with the parameters of the failed reference.

Tutor-5: Short syntax for text property

Whatever you write under a node, starting with a whitespace, will be added to the node's text property. If you have really short text, which does not contain spaces, you can define it as other properties.

node id=main
	My favourite color is #color.

node tag=color text=black
node tag=color text=white
node tag=color text=blue
node tag=color text=red
node tag=color text=green
node tag=color text=yellow

Some results:

• My favourite color is green.
• My favourite color is white.
• My favourite color is green.
• My favourite color is blue.
• My favourite color is blue.
• My favourite color is blue.
• My favourite color is red.
• My favourite color is green.

Tutor-6: Rendering custom property

By default, the node's text property is rendered. But this can be overwritten, appending a dot and the name of the property to the reference.

node id=main
	My favourite color is #color.x.

node tag=color x=black
	text property, not in use
node tag=color x=white
node tag=color x=blue
node tag=color x=red
node tag=color x=green
node tag=color x=yellow

Some results:

• My favourite color is white.
• My favourite color is green.
• My favourite color is black.
• My favourite color is red.
• My favourite color is green.
• My favourite color is blue.
• My favourite color is white.
• My favourite color is black.

Note, that the text property is not used for black.

Tutor-7: Remember and recall

Using variables makes the generated text more natural. Combining them with different properties is a killer feature.

node id=main
	@who=#name is a good @who.sex.

node tag=name text=Maria sex=girl
node tag=name text=Jon sex=boy
node tag=name text=Robert sex=boy
node tag=name text=Lisa sex=girl

Some results are:

• Robert is a good boy.
• Maria is a good girl.
• Jon is a good boy.
• Maria is a good girl.
• Lisa is a good girl.
• Jon is a good boy.
• Jon is a good boy.
• Maria is a good girl.

Variables once set can be recalled any time, any place, and you can use any properties of the recalled node.

Properties make possible to use conjugated forms of the main word (useful for Hungarian and Slavic languages), related pronouns or articles for it (useful for German and Slavic languages), or even just set up synonims, or any related stuff.

This comment is not important for the users, but if you browse the program code, probably you will meet this issue. A variable contains not the rendered text, but the reference of the node selected. When the variable is used, it will be rendered in a special fashion: all its references will choose the very same node which were selected first time.

If the referenced variable is not set, the engine will select the node, which has id property with the specified value. It can be used as fallback if a variable setter is uncertainly selected, or if you just want to use a shortcut for a frequently used text. Also, from the user program, the engine should be called with a root reference, which is "@main" by default.

Tutor-8: Advanced search

You can specify custom tags for search, even using variables as search values.

For a node, multiple values can be defined for the same property (see Android), or you can use asterisk for getting potentially selected for any search value for the property (see Javascript).

node id=main

	For 
	@purp=#purpose.long, 
	@lang=[tag=language,[email protected]]
	is a bad choice.
	[tag=language,[email protected]]
	is a better
	@purp.short language.

node tag=purpose token=backend
	long= backend purposes
	short= backend
node tag=purpose token=frontend
	long= frontend purposes
	short= frontend
node tag=purpose token=android
	long= Android development
	short= Android
node tag=purpose token=windows
	long= Windows development
	short= Windows

node tag=language purpose=windows
	Visual Basic
node tag=language purpose=windows
	C#
node tag=language purpose=backend purpose=android
	Java
node tag=language purpose=backend
	Python
node tag=language purpose=android
	Kotlin
node tag=language purpose=backend
	PHP
node tag=language purpose=frontend
	TypeScript
node tag=language purpose=*
	Javascript

Some results:

• For frontend purposes, TypeScript is a bad choice. Javascript is a better frontend language.
• For Windows development, Visual Basic is a bad choice. Javascript is a better Windows language.
• For frontend purposes, TypeScript is a bad choice. Javascript is a better frontend language.
• For Android development, Kotlin is a bad choice. Java is a better Android language.
• For backend purposes, Java is a bad choice. Javascript is a better backend language.
• For frontend purposes, TypeScript is a bad choice. Javascript is a better frontend language.
• For frontend purposes, TypeScript is a bad choice. Javascript is a better frontend language.
• For Android development, Java is a bad choice. Javascript is a better Android language.

Tutor-9: Decorators

There are three decorators, they alter only the rendering.

• Hide ("h"): the node will be not rendered at all. It's a good practice to set variables silently at the beginning of the script.

• Capitalize ("c"): capitlizes the first letter of the word. It's useful for sentence beginnings.

• Skip first word ("s"): omits rendering of first word of the node. Designed to hide the article, if it's not needed. It's very useful for languages with more form of article (German, Slavic languages).

  node id=main @who=#who!h @what=#what!h

    @who.en!sc + @what.e1: 
    @who.en!c @what.e2.
    -
    @who.de!sc + @what.d1: 
    @who.de!c @what.d2.
  

  node tag=who en= the boy de= Der Junge node tag=who en= the girl de= Das Mädchen node tag=who en= the woman de= Die Frau node tag=who en= the man de= Der Mann

  node tag=what e1= stand e2= is standing d1= Stand d2= steht node tag=what e1= sit e2= is sitting d1= sitzen d2= sitzt node tag=what e1= lay e2= lies d1= liegen d2= lügt

There're some results:

• Girl + lay: The girl lies. -  Mädchen + liegen: Das Mädchen lügt.
• Boy + sit: The boy is sitting. -  Junge + sitzen: Der Junge sitzt.
• Boy + lay: The boy lies. -  Junge + liegen: Der Junge lügt.
• Man + sit: The man is sitting. -  Mann + sitzen: Der Mann sitzt.
• Woman + lay: The woman lies. -  Frau + liegen: Die Frau lügt.
• Girl + stand: The girl is standing. -  Mädchen + Stand: Das Mädchen steht.
• Girl + stand: The girl is standing. -  Mädchen + Stand: Das Mädchen steht.
• Girl + lay: The girl lies. -  Mädchen + liegen: Das Mädchen lügt.

Tutor-10: Weight

By default, every node has a weight property with value of 100. You can define weight value for any node, so you can influence the choice. It a weight is zero, it will be never selected.

In a reference, you can also choose, which tag is used for weighting. If a node of the result set has no such property, it will be counted as 100.

node id=main

	#place

node tag=place weight=40
	I am a #sex
	living in Europe,
	I have [tag=phone,%eu]
	and
	[tag=car,%eu]
node tag=place weight=50
	I am a #sex
	living in USA,
	I have [tag=phone,%usa]
	and
	[tag=car,%usa]
node tag=place weight=20
	I am a #sex
	living in Dubai,
	I have [tag=phone,%dubai]
	and
	[tag=car,%dubai]

node tag=sex weight=49 text=man
node tag=sex weight=51 text=woman

node tag=phone
	iPhone
	eu= 20
	usa= 50
	dubai= 95
node tag=phone
	Android smartphone
	eu= 80
	usa= 50
	dubai= 5

node tag=car
	Opel
	usa= 0
	dubai= 0
node tag=car
	Ford
	dubai= 1
node tag=car
	Chrysler
	eu= 20
	dubai= 1
node tag=car
	Chevrolet
	usa= 150
	dubai= 1
node tag=car
	Mercedes
	usa= 30
	dubai= 5
node tag=car
	Tesla
	eu= 10
	usa= 10
node tag=car
	Fiat
	dubai= 0
	usa= 0
node tag=car
	Ferrari
	usa= 1
	eu= 2
node tag=car
	Lamborghini
	usa= 1
	eu= 2

There're some results:

• I am a man living in USA, I have iPhone and Chevrolet
• I am a man living in Europe, I have Android smartphone and Fiat
• I am a man living in USA, I have Android smartphone and Ford
• I am a woman living in Dubai, I have iPhone and Tesla
• I am a woman living in Dubai, I have iPhone and Lamborghini
• I am a man living in Europe, I have iPhone and Opel
• I am a woman living in Europe, I have Android smartphone and Mercedes
• I am a woman living in Europe, I have Android smartphone and Chevrolet

Include, comment

Any special character at first column can be used as comment.

Include commands should be anywhere in the script. It's a good idea to split up big projects to more files, or build general-purpose includes.

---- include example ---------
node id=main
	Look, mom, a #color #shape!

include shape.inc
include color.inc
------------------------------

Some results:

• Look, mom, a green paralellogram!
• Look, mom, a yellow rectangle!
• Look, mom, a purple square!
• Look, mom, a white paralellogram!
• Look, mom, a black triangle!
• Look, mom, a green paralellogram!
• Look, mom, a cyan rectangle!
• Look, mom, a gray rhombus!

Summary

• The script consist of nodes, nodes have properties with key and value
• The engine starts at the node with id=main
• The engine renders the text property by default
• Node syntax is: node key=value
• The text property can be defined as lines starting with whitespace
• Longer properties can be defined such, but first word must be the name of the property, e.g. key=, then a space followed by value
• When the rendering engine is reaching a reference, it selects a node, and renders it
• Full syntax of reference: @var=[key1=value1,key2=value2,%weightkey].prop!hsc
• Short syntax: @id.prop!hsc or #tag.prop.hsc
• Decorators are: Hide, Skip-first-word and Capitalize

Politics

Known issues

Nothing serious, probably all issues fall to the "won't fix" category.

• In the full reference, only constant weight keys are allowed, variables should be used
• Circular references are not handled, PHP will die with stack overflow error
• Line numbers should be added to error messages
• The program is designed to render the result on-the-fly, so no post-processing applied on the result text. This led to the minor bug that the renderer sometimes adds extra spaces between words at references. Did not fixed, it's not important for HTML
• References should be surrounded by spaces, with some exception, e.g. end-of-sentence punctation works
• The program is originally designed to be easily rewritten to C or C++, e.g. render on-the-fly, easy-to-parse format etc. I gave up this slowly, at last at the point, when I recognized that variables should not only contain a reference to a node, but all subsequent choices should be preserved in order to render the same text when the node is re-selected by a variable.

Project future

A C or C++ implementation for embedded devices (e.g. no memory allocation etc.) would be cool.