Press n or j to go to the next uncovered block, b, p or k for the previous block.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 | 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x | /** @import { BlockStatement, Expression, Identifier, Pattern, Statement } from 'estree' */
/** @import { AST } from '#compiler' */
/** @import { ComponentContext } from '../types' */
import { dev } from '../../../../state.js';
import { extract_paths } from '../../../../utils/ast.js';
import * as b from '../../../../utils/builders.js';
import { get_value } from './shared/declarations.js';
/**
* @param {AST.SnippetBlock} node
* @param {ComponentContext} context
*/
export function SnippetBlock(node, context) {
// TODO hoist where possible
/** @type {Pattern[]} */
const args = [b.id('$$anchor')];
/** @type {BlockStatement} */
let body;
/** @type {Statement[]} */
const declarations = [];
const transform = { ...context.state.transform };
const child_state = { ...context.state, transform };
for (let i = 0; i < node.parameters.length; i++) {
const argument = node.parameters[i];
if (!argument) continue;
if (argument.type === 'Identifier') {
args.push({
type: 'AssignmentPattern',
left: argument,
right: b.id('$.noop')
});
transform[argument.name] = { read: b.call };
continue;
}
let arg_alias = `$$arg${i}`;
args.push(b.id(arg_alias));
const paths = extract_paths(argument);
for (const path of paths) {
const name = /** @type {Identifier} */ (path.node).name;
const needs_derived = path.has_default_value; // to ensure that default value is only called once
const fn = b.thunk(
/** @type {Expression} */ (context.visit(path.expression?.(b.maybe_call(b.id(arg_alias)))))
);
declarations.push(b.let(path.node, needs_derived ? b.call('$.derived_safe_equal', fn) : fn));
transform[name] = {
read: needs_derived ? get_value : b.call
};
// we need to eagerly evaluate the expression in order to hit any
// 'Cannot access x before initialization' errors
if (dev) {
declarations.push(b.stmt(transform[name].read(b.id(name))));
}
}
}
body = b.block([
...declarations,
.../** @type {BlockStatement} */ (context.visit(node.body, child_state)).body
]);
/** @type {Expression} */
let snippet = b.arrow(args, body);
if (dev) {
snippet = b.call('$.wrap_snippet', b.id(context.state.analysis.name), snippet);
}
const declaration = b.const(node.expression, snippet);
// Top-level snippets are hoisted so they can be referenced in the `<script>`
if (context.path.length === 1 && context.path[0].type === 'Fragment') {
context.state.analysis.top_level_snippets.push(declaration);
} else {
context.state.init.push(declaration);
}
}
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