solana_kit_functional 0.2.1

Pipe and compose utilities for the Solana Kit Dart SDK.

solana_kit_functional

Pipe and compose utilities for the Solana Kit Dart SDK, enabling functional pipeline composition on any value.

This is the Dart port of @solana/functional from the Solana TypeScript SDK.

Installation

Install with:

dart pub add solana_kit_functional

If you are working within the solana_kit monorepo, the package resolves through the Dart workspace. Otherwise, specify a version or path as needed.

Documentation

• Package page: https://pub.dev/packages/solana_kit_functional
• API reference: https://pub.dev/documentation/solana_kit_functional/latest/

Usage

The pipe extension

The Pipe<T> extension adds a .pipe() method to every Dart value. It takes a function R Function(T) and returns the result, allowing you to chain transformations in a readable left-to-right pipeline.

import 'package:solana_kit_functional/solana_kit_functional.dart';

final result = 'hello'
    .pipe((value) => value.toUpperCase())
    .pipe((value) => '$value!');
print(result); // HELLO!

Chaining multiple transforms

Pipes can be chained indefinitely. Each step receives the output of the previous step:

import 'package:solana_kit_functional/solana_kit_functional.dart';

final result = 1
    .pipe((value) => value + 1)   // 2
    .pipe((value) => value * 2)   // 4
    .pipe((value) => value - 1);  // 3
print(result); // 3

Type-changing pipelines

The type can change at each step in the pipeline. Dart infers the types automatically:

import 'package:solana_kit_functional/solana_kit_functional.dart';

final result = 42
    .pipe((value) => value + 8)           // int: 50
    .pipe((value) => value.toString())    // String: '50'
    .pipe((value) => '$value items');     // String: '50 items'
print(result); // 50 items

Building immutable objects

Pipe is especially useful for building up immutable data structures step by step:

import 'package:solana_kit_functional/solana_kit_functional.dart';

final config = <String, Object?>{'version': 1}
    .pipe((c) => {...c, 'name': 'my-app'})
    .pipe((c) => {...c, 'debug': false})
    .pipe((c) => {...c, 'maxRetries': 3});
print(config);
// {version: 1, name: my-app, debug: false, maxRetries: 3}

Building Solana transaction messages

The primary use case for pipe in the Solana Kit SDK is constructing transaction messages through a series of transformations. Each SDK function returns a new message, and pipe chains them together fluently:

import 'package:solana_kit_functional/solana_kit_functional.dart';

// Illustrative example showing the intended usage pattern.
// The actual transaction builder functions come from other solana_kit packages.
final message = createTransactionMessage(version: 0)
    .pipe(setTransactionMessageFeePayer(myAddress))
    .pipe(setTransactionMessageLifetimeUsingBlockhash(blockhash))
    .pipe(appendTransactionMessageInstruction(transferInstruction))
    .pipe(appendTransactionMessageInstruction(memoInstruction));

This pattern mirrors the TypeScript SDK, where the pipe() function from @solana/functional is used throughout to build transaction messages:

// TypeScript equivalent from @solana/kit
const message = pipe(
  createTransactionMessage({ version: 0 }),
  tx => setTransactionMessageFeePayer(myAddress, tx),
  tx => setTransactionMessageLifetimeUsingBlockhash(blockhash, tx),
  tx => appendTransactionMessageInstruction(transferInstruction, tx),
);

Combining lists

import 'package:solana_kit_functional/solana_kit_functional.dart';

final combined = [1]
    .pipe((list) => [...list, 2])
    .pipe((list) => [...list, 3])
    .pipe((list) => [...list, 4]);
print(combined); // [1, 2, 3, 4]

Nested pipes

Pipes can be nested within other pipes for complex transformations:

import 'package:solana_kit_functional/solana_kit_functional.dart';

final result = 1
    .pipe((value) => value + 1)
    .pipe((value) => value * 2)
    .pipe((value) => value - 1)
    .pipe(
      (value) => value
          .pipe((v) => v.toString())
          .pipe((v) => '$v!'),
    )
    .pipe((value) => '$value##')
    .pipe((value) => '$value$value');
print(result); // 3!##3!##

Passing named functions

You can pass any function reference directly to pipe, not just lambdas:

import 'package:solana_kit_functional/solana_kit_functional.dart';

Map<String, Object?> dropNulls(Map<String, Object?> map) {
  return Map.fromEntries(map.entries.where((e) => e.value != null));
}

final cleaned = <String, Object?>{'a': 1, 'b': null, 'c': 3}
    .pipe(dropNulls);
print(cleaned); // {a: 1, c: 3}

Error propagation

Errors thrown inside a pipe step propagate naturally:

import 'package:solana_kit_functional/solana_kit_functional.dart';

try {
  'start'
      .pipe((value) => value.toUpperCase())
      .pipe((value) => throw Exception('Something went wrong'))
      .pipe((value) => '$value!'); // never reached
} on Exception catch (e) {
  print(e); // Exception: Something went wrong
}

API Reference

Extensions

• Pipe<T> on T -- Adds the pipe method to every Dart value.
  • R pipe<R>(R Function(T value) transform) -- Applies the given transform function to this value and returns the result.

Example

Use example/main.dart as a runnable starting point for solana_kit_functional.

• Import path: package:solana_kit_functional/solana_kit_functional.dart
• This section is centrally maintained with mdt to keep package guidance aligned.
• After updating shared docs templates, run docs:update from the repo root.

Maintenance

• Validate docs in CI and locally with docs:check.
• Keep examples focused on one workflow and reference package README sections for deeper API details.