smuuf/primi

<?php

declare(strict_types=1);

namespace Smuuf\Primi\Handlers\Kinds;

use \Smuuf\Primi\Context;
use \Smuuf\Primi\Helpers\Func;
use \Smuuf\Primi\Helpers\Interned;
use \Smuuf\Primi\Handlers\HandlerFactory;
use \Smuuf\Primi\Helpers\StringEscaping;

class FStringLiteral extends StringLiteral {

    protected static function handle(array $node, Context $context) {

        $result = '';
        foreach ($node['parts'] as $part) {

            if (\is_array($part)) {

                // Expr node (no other thing would be an array at this point).
                $value = HandlerFactory::runNode($part['core'], $context);
                $result .= $value->getStringValue();

            } else {

                // Just text - add it to the string.
                $result .= $part;

            }

        }

        // Unescape the whole result string - to expand escape sequences - which
        // is expected (this for example allows "\n" to be used as newline char
        // in f-strings).
        return Interned::string(StringEscaping::unescapeString($result));

    }

    public static function reduce(array &$node): void {

        // There can be ordinary non-expression-text nodes and FStringText
        // nodes, so let's build a unified list containing either:
        // 1. Ordinary text as string.
        // 2. FStringExpr nodes as array.
        // ... which will be easy to handle at runtime.

        $unified = [];
        foreach (Func::ensure_indexed($node['core']['parts']) as $part) {

            // Extract "just text" from the non-expr nodes, so we don't have
            // to deal with them later.
            if ($part['name'] !== 'FStringExpr') {
                // Convert double-curly-braces to single ones.
                $unified[] = \str_replace(['{{', '}}'], ['{', '}'], $part['text']);
            } else {
                // Keep expr nodes as-is.
                $unified[] = $part;
            }

        }

        $node['parts'] = $unified;

        // Remove unnecessary parts of the node.
        unset($node['text']);
        unset($node['quote']);
        unset($node['core']);


    }

}