regex

a REGULAR EXPRESSION is a thing that matches strings.

this language uses a REGULAR EXPRESSION to match "pasta" but it's done with a REGULAR EXPRESSION.

TRANSLATED:

make a term that accepts a REGULAR EXPRESSION source as its argument. when storing the REGULAR EXPRESSION, we need to add a "^" to the front of the source so that it matches from the BEGINNING of the input text.

class RegExpTerm extends Term {
	constructor(regex) {
		super()
		this.source = regex.source
		this.regex = new RegExp("^" + regex.source)
	}
}

give it a name.

class RegExpTerm extends Term {
	//...
	name() {
		return `/${this.source}/`
	}
}

check is easy.

class RegExpTerm extends Term {
	//...
	check(text) {
		return this.regex.test(text)
	}
}

bite is easy too.

class RegExpTerm extends Term {
	//...
	bite(text) {
		return text.match(this.regex)?.[0] ?? null
	}
}

that's it.

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