rename-fields

record →
rename-fields(
    transform: expression,
    filter?: predicate
) → record

Transforms selected field names while preserving field values and order. Duplicate resulting names cause an evaluation error.

Parameters

Name	Type	Required	Description
transform	expression	Yes	An expression transforming a field name from text to text.
filter	predicate	No	An optional predicate selecting field names to transform. Omission selects every field.

Argument evaluation

Visits the original field names of the record supplied as pipeline input to this rename-fields call, in field order. Argument expressions use the field name as their context, so .field does not read the surrounding record.

• transform: Evaluated once for each visited field name accepted by the filter, after the filter runs, with that original name as its context. Without a filter, it runs for every name; field values are never supplied.
• filter: When supplied, evaluated once per visited original field name, with that name as its context. A false result preserves the original name and skips the transformation.

Examples

{first-name := "John", last-name := "Doe"} | rename-fields(tokenize-kebab | pascal-case) → {FirstName := "John", LastName := "Doe"}
{first-name := "John", age := 42} | rename-fields(tokenize-kebab | pascal-case, contains("-")) → {FirstName := "John", age := 42}
{" First Name " := "John"} | rename-fields(trim | lower) → {"first name" := "John"}

Kind: Function
Scope: record
Aliases: None