flow

Applies one or more operators to the data pipeline. Operators are composed left-to-right.

Signature

.flow(...operators)

Parameters

Parameter	Type	Description
operators	Operator[]	One or more operators to apply to the data

Returns a new ChartBuilder — flow is immutable.

Example

chart(data)
  .flow(
    derive((d) => d.filter((row) => row.year === 2020)),
    spread({ by: "category", dir: "x" })
  )
  .mark(rect({ h: "value" }));

Reusable flow fragments

Use compose to package a sequence of operators as one reusable operator. The operators retain the same left-to-right order they have in .flow():

const waffle = ({ count, chunkSize, dir }) =>
  compose(
    derive((rows) => rows.flatMap((row) => repeat(row, count))),
    derive((rows) => chunk(rows, chunkSize)),
    spread({ dir, reverse: true }),
    spread({ dir: dir === "x" ? "y" : "x", alignment: "end" })
  );

chart(batches)
  .flow(
    spread({ by: "category", dir: "x", alignment: "end" }),
    waffle({ count: "count", chunkSize: 10, dir: "y" })
  )
  .mark(bottleUnit);

Composed fragments may be nested. compose() with no arguments is an identity operator. When a fragment is added to .flow(), GoFish expands it into its constituent operators so serialization preserves the original operator IR.