b() — svelte Function Reference

Architecture documentation for the b() function in utils.js from the svelte codebase.

Function javascript Compiler Transformer calls 1

Entity Profile

Compiler→ Transformer→ b() — svelte Function Reference

Dependency Diagram

graph TD
  ace7a550_b7b7_88e6_9231_4375f5df3866["b()"]
  89f84d70_5c6c_1980_33f9_650ce42a04ab["PromiseOptimiser"]
  ace7a550_b7b7_88e6_9231_4375f5df3866 -->|defined in| 89f84d70_5c6c_1980_33f9_650ce42a04ab
  c5b1e5e6_49b7_ac9e_9572_7d6c11e99bc7["has_await_expression()"]
  ace7a550_b7b7_88e6_9231_4375f5df3866 -->|calls| c5b1e5e6_49b7_ac9e_9572_7d6c11e99bc7
  style ace7a550_b7b7_88e6_9231_4375f5df3866 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

packages/svelte/src/compiler/phases/3-transform/server/visitors/shared/utils.js lines 336–357

	#apply() {
		if (this.expressions.length === 0) {
			return b.empty;
		}

		if (this.expressions.length === 1) {
			return b.const('$$0', this.expressions[0]);
		}

		const promises = b.array(
			this.expressions.map((expression) => {
				return expression.type === 'AwaitExpression' && !has_await_expression(expression.argument)
					? expression.argument
					: b.call(b.thunk(expression, true));
			})
		);

		return b.const(
			b.array_pattern(this.expressions.map((_, i) => b.id(`$$${i}`))),
			b.await(b.call('Promise.all', promises))
		);
	}