Pattern.Pattern | /mod.ts | fuzzy_octo_guacamole@v2.0.0

type alias Pattern.Pattern

Re-export

import { type Pattern } from "https://deno.land/x/fuzzy_octo_guacamole@v2.0.0/mod.ts";
const { Pattern } = Pattern;

Pattern<a> is the generic type for patterns matching a value of type a. A pattern can be any (nested) javascript value.

They can also be wildcards, like P._, P.string, P.number, or other matchers, like P.when(predicate), P.not(pattern), etc.

Read Patterns documentation on GitHub

Examples

const pattern: P.Pattern = { name: P.string }

definition: Matcher<a, unknown, any, any> | (a extends Primitives ? a : unknown extends a ? UnknownPattern : a extends readonly (infer i)[] ? a extends readonly [any, ...any] ? readonly [index in keyof a]: Pattern<a[index]> : readonly [] | readonly [Pattern<i>, ...Pattern<i>[]] : a extends Map<infer k, infer v> ? Map<k, Pattern<v>> : a extends Set<infer v> ? Set<Pattern<v>> : a extends object ? readonly [k in keyof a]?: Pattern<Exclude<a[k], undefined>> : a)

Examples

const pattern: P.Pattern = { name: P.string }

Type Parameters

Examples

const userPattern = { name: P.string } type User = P.infer

Type Parameters

p extends Pattern<any>

definition: InvertPattern<p>

variable Pattern.Pattern

Re-export

import { Pattern } from "https://deno.land/x/fuzzy_octo_guacamole@v2.0.0/mod.ts";
const { Pattern } = Pattern;

P.any is a wildcard pattern, matching any value.

Read P.any documentation on GitHub

function Pattern.Pattern

Re-export

import { Pattern } from "https://deno.land/x/fuzzy_octo_guacamole@v2.0.0/mod.ts";
const { Pattern } = Pattern;

optional<input, p extends unknown extends input ? UnknownPattern : Pattern<input>>(pattern: p): OptionalP<input, p>

when<input, p extends (value: input) => unknown>(predicate: p): GuardP<input, p extends (value: any) => value is infer narrowed ? narrowed : never>

P.when((value) => boolean) returns a pattern which matches if the predicate returns true for the current input.

when<input, narrowed extends input, excluded>(predicate: (input: input) => input is narrowed): GuardExcludeP<input, narrowed, excluded>

select(): AnonymousSelectP

P.select() is a pattern which will always match, and will inject the selected piece of input in the handler function.

select<input, patternOrKey extends string | (unknown extends input ? UnknownPattern : Pattern<input>)>(patternOrKey: patternOrKey): patternOrKey extends string ? SelectP<patternOrKey> : SelectP<symbols.anonymousSelectKey, input, patternOrKey>

select<input, p extends unknown extends input ? UnknownPattern : Pattern<input>, k extends string>(key: k, pattern: p): SelectP<k, input, p>

P.optional(subpattern) takes a sub pattern and returns a pattern which matches if the key is undefined or if it is defined and the sub pattern matches its value.

Read P.optional documentation on GitHub