31:T728,html`

RiScript is, more or less, a subset of Dial, the scripting language originally created for the Dialogic system (and used in this excellent game). The grammar files for the language are here. If you're using RiTa in Observable (this site), check the notebook here for tools like the rs template.

Related Resources

The RiTa reference in observable
The RiTa website: examples, docs, gallery, etc.
Generating with RiTa grammars and Markov chains
Using RiScript and RiTa Grammars within Twine
RiTa's Lexicon and Letter-to-Sound engine

`32:T712,md` Other built-in transforms:

transform	description	alias
articlize()	adds the correct article according to the phonemes	art()
capitalize()	capitalizes the first letter of the phrase	cap()
uppercase()	capitalizes all letters of the phrase	uc()
quotify()	adds (smart) quotes around the phrase	qq()
norepeat()	ensures a choice will never repeat its output	nr()
pluralize()	pluralizes the phrase via the RiTa inflector	s()

Each has a short form (or alias) that may be more convenient.
You can also create your own *custom* transforms as described below. `33:T7a2,transforms = md`--- ### Transforms As mentioned above, **transforms** are small functions that can be included in RiScript to modify the expression they're attached to. A number of transforms are defined by default:

transform	description	alias
articlize()	adds the correct article according to the phonemes	art()
capitalize()	capitalizes the first letter of the phrase	cap()
uppercase()	capitalizes all letters of the phrase	uc()
quotify()	adds (smart) quotes around the phrase	qq()
norepeat()	ensures a choice will never repeat its output	nr()
pluralize()	pluralizes the phrase via the RiTa inflector	s()

Each has a short form (or alias) that may be more convenient.

You can also create your own custom transforms as follows... `34:T42b,dynamics=md`--- ### Dynamic Symbols ♦ It is often useful, when scripting, to store longer expressions as [symbols](#symbol), as shown above. In RiScript, such expressions can involve multiple, possibly nested, choices and transforms, each including randomized elements. But if symbols are evaluated in the traditional way, once their value is set, they will simply repeat when used multiple times in the same script, and the randomized elements will be forever fixed. While we may want this behavior in some cases (as with our oxen above), we can avoid it by using [RiTa grammars](./rita-grammars). The reason RiTa grammars don't fix the value for symbols is that they use, by default, what RiScript calls **dynamic symbols**; symbols which are evaluated *each* time they are encountered (somewhat like a function or closure in typical languages). But you may also want this behavior when you're *not* explicitly using grammars. In such cases you can declare variables to be *dynamic* using the \`$$\` keyword: ` 35:T40f,html`

Related Resources

The RiTa reference in observable
The RiTa website: examples, docs, gallery, etc.
Tools for RiTa in observable, including the rs template
Generating with RiTa grammars and Markov chains
Using RiScript and RiTa Grammars within Twine
RiTa's Lexicon and Letter-to-Sound engine

`36:T18f7, class Editor { constructor (params = {}){ this.value = params.value || "//\nadd code here\n\n\n"; this.theme = params.theme ? params.theme + "Mode" : "darkMode"; this.width = params.width || "800px"; this.height = params.height || "auto"; this.fontSize = params.fontSize || "16px"; this.render } toString() { return this.value.trim(); } render() { // modified from https://observablehq.com/@benatkin/codemirror-iframe let value = this.value, t = this.theme; let fn = ({CodeMirror} = {}) => { return ({id, value, t}) => { CodeMirror.defineSimpleMode("RiScript", { start: [ //RiScript { regex: /$([^)]*\|)+[^)]*$/g, token: "choice" }, //choices { regex: /(\.[\w]+()?)/g, token: "transform" }, //transforms { regex: /\$\w+/g, token: "symbol" }, //symbol { regex: /\$\$\w+/g, token: "dynamic" }, //dynamic symbol { regex: /\/\/.*/g, token: "comment" }, //single line comment { regex: /\/\*/, token: "comment", next: "comment" }, //multi lines comment ], comment: [ {regex: /.*?\*\//, token: "comment", next: "start"}, {regex: /.*/, token: "comment"} ], }); const cm = CodeMirror(document.body, { value, mode: 'RiScript', theme: t, lineNumbers: true }) CodeMirror.modeURL = 'https://codemirror.net/mode/%N/%N.js' cm.on('change', (cm, changes) => { window.parent.postMessage({ id, value: cm.getValue(), height: document.body.offsetHeight }, `https://${document.domain}`) }) setInterval(() => { window.parent.postMessage({ id, height: document.body.offsetHeight }, `https://${document.domain}`) }, 300) } } const randomId = `el${Math.floor(Math.random() * 1000000)}` const frameSrc = ` ` const frameStyle = `width: ` + this.width + `;height: ` + this.height + `; border: 0; overflow-y: auto;` const frame = html`` const messageListener = event => { if (document.contains(frame)) { if (event.data.id == randomId) { if (event.data.value != undefined) { this.value = event.data.value; frame.value = event.data.value frame.dispatchEvent(new CustomEvent("input")) } frame.style.height = `${event.data.height}px` } } else { window.removeEventListener('message', messageListener) } } window.addEventListener('message', messageListener, false) frame.srcdoc = frameSrc return frame } }37:[{"id":"5ad1543f837d40bf1e53e53aed49c6130d630660020409c1b8667bdba391951d629d12003864064f1c31034230eb893315f9d46b9d325922eda0ebfdfa1bbd38","href":"https://static.observableusercontent.com/files/5ad1543f837d40bf1e53e53aed49c6130d630660020409c1b8667bdba391951d629d12003864064f1c31034230eb893315f9d46b9d325922eda0ebfdfa1bbd38","name":"RiTa@3.png","type":"image/png","lastModified":1612991963918.926,"size":26700},{"id":"ecfddfaa4c9eea6524a15be82eaca2db272b53a356435c8f89b8e2d692875dabdffb96f9c9c5678fb5a6bc1e436056f9d5cce74b7547ace6f69ec2d56a944560","href":"https://static.observableusercontent.com/files/ecfddfaa4c9eea6524a15be82eaca2db272b53a356435c8f89b8e2d692875dabdffb96f9c9c5678fb5a6bc1e436056f9d5cce74b7547ace6f69ec2d56a944560","name":"editor.css","type":"text/css","lastModified":1634654961643.331,"size":4144}] 2f:{"title":"Scripting RiTa ","cells":[{"id":299,"value":"md`# Scripting RiTa

\n\nA tutorial on [RiScript](https://rednoise.org/rita/reference/riscript.html), the simple, writer-oriented scripting language included with [RiTa](https://www.npmjs.com/package/rita). RiScript expressions, described below, can be included in any RiTa [grammar](https://rednoise.org/rita/tutorials/grammars.html), or run directly via [RiTa.evaluate()](https://rednoise.org/rita/reference/RiTa/evaluate/).\n`\n\n","pinned":false,"hidden":false,"mode":"ojs"},{"id":379,"value":"$31","pinned":false,"hidden":false,"mode":"ojs"},{"id":136,"value":"html`

${result}

`","pinned":false,"hidden":false,"mode":"ojs"},{"id":296,"value":"md`In this first example we evaluate the **RiScript** code in the editor below, once per second, and display it above. As you read, you can edit the script and watch as the text above updates...`","pinned":false,"hidden":false,"mode":"ojs"},{"id":295,"value":"ed.render()","pinned":false,"hidden":false,"mode":"ojs"},{"id":293,"value":"md`### Explanation\nThe script above uses two **choice** elements, in parentheses, \\`(dog | child | ox)\\` and \\`(dining | conversing)\\`. Each time the script is run, one of the options for each choice is selected. \n`","pinned":false,"hidden":false,"mode":"ojs"},{"id":377,"value":"explanation=rs`\nThe script also uses the *pluralize* **transform**. Transforms are basically functions that modify the text they are attached to, once it has been resolved. In this case the resolved text fragment \\\$either (dog).qq or (child).qq or (ox).qq \\\$ is pluralized via the RiTa inflector.`","pinned":false,"hidden":false,"mode":"ojs"},{"id":376,"value":"$32","pinned":false,"hidden":false,"mode":"ojs"},{"id":375,"value":"","pinned":true,"hidden":false,"mode":"ojs"},{"id":281,"value":"choice=md`---\n### Choice\nThe **choice** primitive, as mentioned above, allows us to make a random selection from a group of options. Choices can contain any type of RiScript expression, including other choices.\n\nWe can also include the empty string as follows (which is surprisingly useful):\n`","pinned":false,"hidden":false,"mode":"ojs"},{"id":280,"value":"{\n let script = \"(everything | something | )\";\n let el = html` ⮕ ${d}
click me ☝
`;\n el.onclick = () => mutable d = RiTa.evaluate(script);\n return el;\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":279,"value":"weightedChoice=md`---\n\nBy default RiScript chooses randomly between the options in a **choice**. But we can also change the **weighting** for a rule so that it is selected more or less frequently. For example, if we wanted more children than oxen or dogs, we could say \\`\\`\\`(dog | child [8] | ox)\\`\\`\\`, specifying that we want the \\`child\\` options to be 8 times more likely than the other two.\n\nHere's a test with 100 evaluations (click to rerun it):\n`","pinned":false,"hidden":false,"mode":"ojs"},{"id":278,"value":"{\n let rule = \"'(dog | child [8] | ox).s'\";\n let el = html` ⮕ ${e}`;\n let results = { dogs: 0, children: 0, oxen: 0 };\n for (let i = 0; i < 100; i++)\n results[RiTa.evaluate(\"(dog | child [8] | ox).s\")]++;\n el.onclick = () =>\n (mutable e = Object.keys(results).map((k) => k + \": \" + results[k] + \" \"));\n return el;\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":370,"value":"symbol=md`---\n### Symbols\nSymbol definitions start a line and do not generate any output. They simply create or update a value to be used elsewhere (variables in JavaScript can also be used when passed in via the script's [context](#evalContext)).\n`\n ","pinned":false,"hidden":false,"mode":"ojs"},{"id":369,"value":"explanationCode = md`\nIf you wanted to write the code from the editor above more verbosely, you could assign the parts to symbols:\n\n

$mammal=(dog | child | ox)\n$verb=(dining | conversing)\nThe $mammal.pluralize were $verb.\n

\n`","pinned":false,"hidden":false,"mode":"ojs"},{"id":368,"value":"md`\nLet's says we wanted to generate sentences in the following form: \n\n

  Oxen are unruly, but my ox is the best.

\n\nBut we want to be able to substitute different mammals as before. If we use two separate choices, they could end up with different values, e.g., \"Dogs are unruly, but my ox is the best\", which isn't what we want. So we could define a symbol, which would be evaluated only once, but then referenced twice:`","pinned":false,"hidden":false,"mode":"ojs"},{"id":367,"value":"symbolCode = html`\n

$mammal=(dog | child | ox)\n$mammal.pluralize.ucf are unruly, but my $mammal is the best.\n

\n`","pinned":false,"hidden":false,"mode":"ojs"},{"id":366,"value":"{\n let script = \"$mammal=(dog | child | ox)\\n$mammal.pluralize.ucf are unruly, but my $mammal is the best.\";\n let el = html` ⮕ ${f}`;\n el.onclick = () => mutable f = RiTa.evaluate(script);\n return el;\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":273,"value":"inline=md` ---\n### Inline Symbols\n\nInline symbols allow to create *and* output a new variable at the same time. For example, the above script, in asingle line:`\n\n","pinned":false,"hidden":false,"mode":"ojs"},{"id":272,"value":"inlineCode = html`\n

($mammal=(dog | child | ox)).pluralize.ucf are unruly, but my $mammal is the best.\n

\n`","pinned":false,"hidden":false,"mode":"ojs"},{"id":271,"value":"{\n let script = \"($mammal=(dog | child | ox)).pluralize.ucf are unruly, but my $mammal is the best.\"\n let el = html` ⮕ ${g}`;\n el.onclick = () => mutable g = RiTa.evaluate(script);\n return el;\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":363,"value":"md`Or, another example:`\n","pinned":false,"hidden":false,"mode":"ojs"},{"id":362,"value":"inlineCode2 = html`\n

($name=(Jane | Bill)) was from ($place=(New York | Berlin | Shanghai)).\n$name finds $place cold and wet in winter.\n

\n`\n","pinned":false,"hidden":false,"mode":"ojs"},{"id":361,"value":"{\n let script = \"($name=(Jane | Bill)) was from ($place=(New York | Berlin | Shanghai)). $name finds $place cold and wet in winter.\"\n let el = html` ⮕ ${e}`;\n el.onclick = () => mutable e = RiTa.evaluate(script);\n return el;\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":360,"value":"rs`We are basically telling RiScript to _remember_ the value it generated for our symbol and to _re-use_ it whenever it sees that symbol in the future`","pinned":false,"hidden":false,"mode":"ojs"},{"id":270,"value":"$33","pinned":false,"hidden":false,"mode":"ojs"},{"id":268,"value":"customTransforms = md`---\n### Custom Transforms\nYou can create your own transforms to do all sorts of things: changing the visual display of elements, calling RiTa functions from within scripts, or fetching data from a remote API.\n\nAs a simple example, let's create a **custom transform** by adding a rhyme to the option selected in a choice expression. We can call our transform *rhymes* and invoke it like this:`","pinned":false,"hidden":false,"mode":"ojs"},{"id":267,"value":"{\n let rs = '(dog | child | ox).rhymes';\n let el = html` ⮕ ${h}`;\n el.onclick = () => mutable h = RiTa.addTransform('rhymes') && RiTa.evaluate(rs);\n return el;\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":266,"value":"md`Since we haven't yet _defined_ the transform, it is output literally (as text) rather than being executed.`","pinned":false,"hidden":false,"mode":"ojs"},{"id":265,"value":"md`So let's create a function for the transform (I'll call it *addRhyme* for demo purposes, although it is more common to use the same name):`","pinned":false,"hidden":false,"mode":"ojs"},{"id":264,"value":"addRhyme = function(word) { \n let res = RiTa.rhymes(word); // get the rhymes\n return word + ' rhymes with ' + RiTa.random(res); // append a random one\n}","pinned":true,"hidden":false,"mode":"ojs"},{"id":263,"value":"html`Now that we've defined our function, we can add it to RiTa like this:

  RiTa.addTransform('rhymes', addRhyme);\n

Note that the 1st argument is the name we want to use for the transform, and the 2nd is the function itself.

\nNow we're ready to try again...`","pinned":false,"hidden":false,"mode":"ojs"},{"id":262,"value":"{\n let rs = '(dog | child | ox).rhymes';\n let el = html` ⮕ ${i}`;\n RiTa.addTransform('rhymes', addRhyme);\n el.onclick = () => mutable i = RiTa.evaluate(rs);\n return el;\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":261,"value":"md`And there we have our first custom transform... 💡`\n","pinned":false,"hidden":false,"mode":"ojs"},{"id":355,"value":"evalContext = md`---\n### Evaluation Context\nWhen using RiScript as part of a larger system like a game or other interactive experience, it is often useful to refer to variables from the larger **context**. For example, in a game we might want to refer to the current state of the player in our scripts. We can do this by passing the context as the 2nd argument to the \\`evaluate()\\` function as follows:`","pinned":false,"hidden":false,"mode":"ojs"},{"id":354,"value":"md`\n~~~js\nRiTa.evaluate(\"$player.name(), you have $player.score() points!\", context);\n~~~\n\nThe \\`context\\` here is simply a JavaScript object (you can think of it as a sort of *world-state*) which can include abritrarily nested objects with properties and functions:`","pinned":false,"hidden":false,"mode":"ojs"},{"id":353,"value":"context = ({\n player: {\n name: 'Scott',\n score: 200,\n damage: 50,\n strength: 30.6\n },\n enemy: {\n damage: 80,\n strength: 10.4\n }\n})","pinned":false,"hidden":false,"mode":"ojs"},{"id":352,"value":"md`When you pass a context to RiTa.evaluate(), you can then use any symbols it contains within your scripts via the usual \\`$symbolName\\` notation.`","pinned":false,"hidden":false,"mode":"ojs"},{"id":351,"value":"{\n let rs = '$player.name(), you have only $player.score() points. Keep going!';\n let el = html`
⮕ ${j}`;\n el.onclick = () => mutable j = RiTa.evaluate(rs, context);\n return el;\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":260,"value":"$34","pinned":false,"hidden":false,"mode":"ojs"},{"id":259,"value":"$$$myComplexExpresson=\"(a (very | super |) (heavi|deep)ly-nested).ucf choice expression.\";","pinned":false,"hidden":false,"mode":"ojs"},{"id":258,"value":"{\n let el = html` ⮕ ${k}`;\n el.onclick = () => mutable k = RiTa.evaluate($$myComplexExpresson);\n return el;\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":257,"value":"md`\nEach time such a variable is encountered, it is evaluated as if for the first time. \n

\nNote that the **$$** notation is only for *creating* dynamic symbols - to refer to them in your scripts, you should use the single **$** as usual:\n

\n`\n","pinned":false,"hidden":false,"mode":"ojs"},{"id":347,"value":"dynamicSymbolCode = html`\n

 $$mammal=(dog | child | ox)\n My $mammal is often unruly.\n

`","pinned":false,"hidden":false,"mode":"ojs"},{"id":346,"value":"md`\n-------\n\n### Static Symbols in Grammars ♦\n\nConversely, if you working with grammars and you DO WANT a variable to maintain its value, you can prepend a single **$** symbol, which tells the interpreter it is a static (non-dynamic) variable.\n
\n`","pinned":false,"hidden":false,"mode":"ojs"},{"id":256,"value":"diamond=html`

♦ (slightly) advanced

`","pinned":false,"hidden":false,"mode":"ojs"},{"id":345,"value":"$35","pinned":false,"hidden":false,"mode":"ojs"},{"id":255,"value":"md`---\n\n## Appendix`\n","pinned":false,"hidden":false,"mode":"ojs"},{"id":344,"value":"RiTa.VERSION","pinned":false,"hidden":false,"mode":"ojs"},{"id":343,"value":"import { RiTa, rs } from '@dhowe/rita'","pinned":true,"hidden":false,"mode":"ojs"},{"id":342,"value":"ed = editor({ width: '750px', theme: 'light', value: '\\nThe (dog | child | ox).pluralize were (dining | conversing) silently.\\n' })","pinned":false,"hidden":false,"mode":"ojs"},{"id":341,"value":"import { textarea, button } from \"@jashkenas/inputs\"","pinned":true,"hidden":false,"mode":"ojs"},{"id":340,"value":"import {highlightRs} from '@dhowe/rshl'","pinned":true,"hidden":false,"mode":"ojs"},{"id":254,"value":"mutable a = \"\"","pinned":false,"hidden":false,"mode":"ojs"},{"id":253,"value":"mutable b = \"\"","pinned":false,"hidden":false,"mode":"ojs"},{"id":252,"value":"mutable c = \"\" ","pinned":false,"hidden":false,"mode":"ojs"},{"id":250,"value":"mutable d = \"\";","pinned":false,"hidden":false,"mode":"ojs"},{"id":338,"value":"mutable e = \"\";","pinned":false,"hidden":false,"mode":"ojs"},{"id":337,"value":"mutable f = \"\";","pinned":false,"hidden":false,"mode":"ojs"},{"id":336,"value":"mutable g = \"\";","pinned":false,"hidden":false,"mode":"ojs"},{"id":335,"value":"mutable h = \"\";","pinned":false,"hidden":false,"mode":"ojs"},{"id":334,"value":"mutable i= \"\";","pinned":false,"hidden":false,"mode":"ojs"},{"id":333,"value":"mutable j = \"\";","pinned":false,"hidden":false,"mode":"ojs"},{"id":332,"value":"mutable k = \"\"","pinned":false,"hidden":false,"mode":"ojs"},{"id":331,"value":"mutable l = \"\"","pinned":false,"hidden":false,"mode":"ojs"},{"id":241,"value":"editor = (config = {}) => new Editor(config)","pinned":false,"hidden":false,"mode":"ojs"},{"id":240,"value":"$36","pinned":false,"hidden":false,"mode":"ojs"},{"id":83,"value":"result = {\n while (true) {\n yield Promises.delay(2000, (() => { \n try {\n return RiTa.evaluate(ed.toString()) \n }\n catch(e) {\n console.warn(e);\n return ed.toString();\n }\n })());\n }\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":328,"value":"editorCSS = FileAttachment(\"editor.css\").url()","pinned":false,"hidden":false,"mode":"ojs"},{"id":327,"value":"highlightRs([symbolCode, inlineCode, inlineCode2, explanationCode, dynamicSymbolCode]);","pinned":false,"hidden":false,"mode":"ojs"}],"files":"$W37","stdlib":"1","titling":"auto"}