Function flow

Variadic point-free composition — left-to-right.

const parseUserName = flow(
  (raw: string) => parseConfig(raw),
  map((cfg) => cfg.user),
  flatMap((u) => u.name ? ok(u.name) : err({ kind: "missing" })),
);

parseUserName(raw); // Result<string, ParseError | { kind: "missing" }>
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Use pipe from @onrails/result when you have a starting value; use flow when you want to define a reusable composed function.

Variadic point-free composition — left-to-right.

const parseUserName = flow(
  (raw: string) => parseConfig(raw),
  map((cfg) => cfg.user),
  flatMap((u) => u.name ? ok(u.name) : err({ kind: "missing" })),
);

parseUserName(raw); // Result<string, ParseError | { kind: "missing" }>
Copy

Use pipe from @onrails/result when you have a starting value; use flow when you want to define a reusable composed function.

Variadic point-free composition — left-to-right.

const parseUserName = flow(
  (raw: string) => parseConfig(raw),
  map((cfg) => cfg.user),
  flatMap((u) => u.name ? ok(u.name) : err({ kind: "missing" })),
);

parseUserName(raw); // Result<string, ParseError | { kind: "missing" }>
Copy

Use pipe from @onrails/result when you have a starting value; use flow when you want to define a reusable composed function.

Variadic point-free composition — left-to-right.

const parseUserName = flow(
  (raw: string) => parseConfig(raw),
  map((cfg) => cfg.user),
  flatMap((u) => u.name ? ok(u.name) : err({ kind: "missing" })),
);

parseUserName(raw); // Result<string, ParseError | { kind: "missing" }>
Copy

Use pipe from @onrails/result when you have a starting value; use flow when you want to define a reusable composed function.

Variadic point-free composition — left-to-right.

const parseUserName = flow(
  (raw: string) => parseConfig(raw),
  map((cfg) => cfg.user),
  flatMap((u) => u.name ? ok(u.name) : err({ kind: "missing" })),
);

parseUserName(raw); // Result<string, ParseError | { kind: "missing" }>
Copy

Use pipe from @onrails/result when you have a starting value; use flow when you want to define a reusable composed function.

Variadic point-free composition — left-to-right.

const parseUserName = flow(
  (raw: string) => parseConfig(raw),
  map((cfg) => cfg.user),
  flatMap((u) => u.name ? ok(u.name) : err({ kind: "missing" })),
);

parseUserName(raw); // Result<string, ParseError | { kind: "missing" }>
Copy

Use pipe from @onrails/result when you have a starting value; use flow when you want to define a reusable composed function.

Variadic point-free composition — left-to-right.

const parseUserName = flow(
  (raw: string) => parseConfig(raw),
  map((cfg) => cfg.user),
  flatMap((u) => u.name ? ok(u.name) : err({ kind: "missing" })),
);

parseUserName(raw); // Result<string, ParseError | { kind: "missing" }>
Copy

Use pipe from @onrails/result when you have a starting value; use flow when you want to define a reusable composed function.

Variadic point-free composition — left-to-right.

const parseUserName = flow(
  (raw: string) => parseConfig(raw),
  map((cfg) => cfg.user),
  flatMap((u) => u.name ? ok(u.name) : err({ kind: "missing" })),
);

parseUserName(raw); // Result<string, ParseError | { kind: "missing" }>
Copy

Use pipe from @onrails/result when you have a starting value; use flow when you want to define a reusable composed function.