classRhsItem

packages/lemon-parser/src/Ast/RhsItem.php:21

final class RhsItem

Public API: explicitly declared with @visibility public.

One position on the right-hand side of a rule.

Usually one symbol, but Lemon lets several terminals share a position, written A|B|C; the position then matches any of them. An alias in parentheses names the value of the position in the rule's code.

Reading a multi-terminal positiondoctest

$file = (new \LemonParser\Parser())->parse("cmd ::= BEGIN|START trans_opt(X).\n");
    $items = $file->rules()[0]->items;
    [$items[0]->isMultiTerminal(), array_map(static fn ($symbol) => $symbol->name, $items[0]->symbols), $items[1]->alias] // => [true, ['BEGIN', 'START'], 'X']

Properties§

public non-empty-list<Symbol> $symbols

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public string|null $alias

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Methods§

public function __construct(public non-empty-list<Symbol> $symbols, public string|null $alias)

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Parameters

`$symbols`	`non-empty-list<Symbol>`	The symbol, or the terminals that share the position
`$alias`	`string\|null`	The name given to the position's value, or null