classPrinter

packages/bison-parser/src/Printer/Printer.php:27

final class Printer

Public API: explicitly declared with @visibility public.

Writes a syntax tree back out as a Bison grammar file.

The output is not the original text: whitespace and comments are gone, and every declaration and rule is laid out one way. It is a grammar Bison reads to the same tree, which is what lets a tree be checked by printing it and reading it again.

Printing a grammar backdoctest

$file = (new \BisonParser\Parser())->parse("%token NUM   // numbers\n%%\nexpr : NUM | expr '+' NUM { \$\$ = \$1 + \$3; } ;");
    (new \BisonParser\Printer\Printer())->print($file) // => "%token NUM\n%%\nexpr:\n  NUM\n| expr '+' NUM { \$\$ = \$1 + \$3; }\n;\n"

Methods§

public function __construct(
    private DeclarationPrinter $declarations = new \BisonParser\Printer\DeclarationPrinter(),
    private RhsPrinter $rhs = new \BisonParser\Printer\RhsPrinter(),
)

source §

Parameters

`$declarations`	`DeclarationPrinter`	Writes declarations
`$rhs`	`RhsPrinter`	Writes right-hand sides

Calls 2

new DeclarationPrinter line 34
new RhsPrinter line 35

public function print(GrammarFile $file): string

source §

Writes a whole file.

Parameters

$file GrammarFile The tree

Returns

string The grammar file text

Test cases 2

ParseBench::benchRoundTrip calls
PrinterTest::testPrint calls

Calls 3

method-call DeclarationPrinter::print() line 50
method-call Printer::rule() line 54
function-call implode line 56

public function rule(Rule $rule): string

source §

Writes one rule, one alternative per line.

Parameters

$rule Rule The rule

Returns

string The rule text

Test cases 1

PrinterTest::testRule calls

Called from 1

method-call BisonParser\Printer\Printer::print() packages/bison-parser/src/Printer/Printer.php:54

Calls 2

method-call Printer::alternative() line 76
function-call implode line 80

public function alternative(Alternative $alternative): string

source §

Writes the items of one alternative separated by spaces.

Parameters

$alternative Alternative The alternative

Returns

string The items, or `%empty` for an alternative with none

Test cases 1

PrinterTest::testAlternative calls

Called from 1

method-call BisonParser\Printer\Printer::rule() packages/bison-parser/src/Printer/Printer.php:76

Calls 2

method-call RhsPrinter::print() line 97
function-call implode line 100

Private surface 2§

Implementation details, listed for orientation only.

private DeclarationPrinter $declarations = new \BisonParser\Printer\DeclarationPrinter()

private RhsPrinter $rhs = new \BisonParser\Printer\RhsPrinter()

Test cases 7§

Test cases that cover or call this symbol, from the coverage report and from the analyzed test sources.

Dedicated tests 3

Other tests reaching this symbol 4