classBisonGrammarCompiler

packages/sql-faker/src/Compiler/Bison/BisonGrammarCompiler.php:40

final class BisonGrammarCompiler

Public API: explicitly declared with @visibility public.

Turns a Bison grammar file into the grammar the generators walk.

The file is read with bison-parser; this class keeps what generation needs: every alternative of every rule as a sequence of terminals and nonterminals. A name is a nonterminal when a rule defines it and a terminal when %token declares it; a character literal is a terminal named by its character; actions, precedence marks, tags, aliases and string literals are left out. Alternatives of a rule defined in several places are joined in file order.

Compiling a small grammardoctest

$grammar = (new \SqlFaker\Compiler\Bison\BisonGrammarCompiler())->compile("%token NUM\n%start expr\n%%\nexpr: expr '+' term { \$\$ = \$1 + \$3; } | term ;\nterm: NUM ;\n");
    [$grammar->startSymbol, array_keys($grammar->ruleMap), count($grammar->ruleMap['expr']->alternatives)] // => ['expr', ['expr', 'term'], 2]

Methods§

public function __construct(private Parser $parser = new \BisonParser\Parser())

source §

Parameters

$parser Parser Reads Bison grammar files

Calls 1

new Parser line 45

public function compile(string $source): Grammar

source §

Compiles a grammar file.

Parameters

$source string The text of the `.y` or `.yy` file

Returns

Grammar The grammar

Throws

SyntaxException When the file is not a grammar Bison accepts, which includes a file without rules

UnknownSymbolException When a rule uses a name that is neither a rule nor a declared token

Test cases 4

Calls 8

method-call Parser::parse() line 61
method-call BisonGrammarCompiler::declaredTokens() line 67
new Production line 72
method-call BisonGrammarCompiler::symbols() line 72
new ProductionRule line 76
function-call array_merge line 76
new Grammar line 79
method-call BisonGrammarCompiler::startSymbol() line 79

public function declaredTokens(GrammarFile $file): array<string, true>

source §

Collects the names %token declares.

Parameters

$file GrammarFile The tree

Returns

array<string, true> The names

Test cases 1

BisonGrammarCompilerTest::testDeclaredTokens calls

Called from 1

method-call SqlFaker\Compiler\Bison\BisonGrammarCompiler::compile() packages/sql-faker/src/Compiler/Bison/BisonGrammarCompiler.php:67

Calls 2

method-call GrammarFile::allDeclarations() line 92
class-const SymbolClass::Token() line 93

public function symbols(
    Alternative $alternative,
    array<string, true> $defined,
    array<string, true> $declared,
): list<Symbol>

source §

Turns the symbols of an alternative into terminals and nonterminals.

Parameters

`$alternative`	`Alternative`	The alternative
`$defined`	`array<string, true>`	Names rules define
`$declared`	`array<string, true>`	Names `%token` declares

Returns

list<Symbol> The symbols in order, string literals left out

Throws

UnknownSymbolException When a name is neither defined nor declared

Test cases 2

Called from 1

method-call SqlFaker\Compiler\Bison\BisonGrammarCompiler::compile() packages/sql-faker/src/Compiler/Bison/BisonGrammarCompiler.php:72

Calls 6

method-call Alternative::symbols() line 120
class-const SymbolKind::CharLiteral() line 121
new Terminal line 122
class-const SymbolKind::String() line 123
new NonTerminal line 126
new UnknownSymbolException line 130

public function startSymbol(GrammarFile $file): string

source §

Finds the start symbol: what %start names, or else the first rule.

Parameters

$file GrammarFile The tree, with at least one rule

Returns

string The start symbol

Test cases 1

BisonGrammarCompilerTest::testStartSymbol calls

Called from 1

method-call SqlFaker\Compiler\Bison\BisonGrammarCompiler::compile() packages/sql-faker/src/Compiler/Bison/BisonGrammarCompiler.php:79

Calls 2

method-call GrammarFile::allDeclarations() line 146
method-call GrammarFile::rules() line 152

Private surface 1§

Implementation details, listed for orientation only.

private Parser $parser = new \BisonParser\Parser()

Test cases 8§

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

Dedicated tests 8