function minus($minuend, $subtrahend)
{
return $minuend - $subtrahend;
}
# N -> number
$N = new RegexParser("#^(0|[1-9][0-9]*)#", function ($match) {
return (int) $match;
});
# P -> "-" N
$P = new ConcParser(array(new StringParser("-"), $N), function ($minus, $n) {
return $n;
});
# Naive left-recursive grammar looks like this and raises an exception
# when instantiated.
try {
# S -> N
# S -> S P
$grammar = new Grammar("S", array("S" => new LazyAltParser(array("N", new ConcParser(array("S", "P"), "minus"))), "P" => $P, "N" => $N));
var_dump(false);
} catch (GrammarException $e) {
# Left-recursive in S
var_dump(true);
}
# Fix the grammar like so:
# S -> N P*
$grammar = new Grammar("S", array("S" => new ConcParser(array($N, new GreedyStarParser("P")), function ($n, $ps) {
return array_reduce($ps, "minus", $n);
# clever bit
}), "P" => $P, "N" => $N));
var_dump($grammar->parse("5-4-3") === -2);
# true
foreach ($this->mAction as $id => $row) {
$s .= "\t{$id} => array(\n";
foreach ($row as $t => $action) {
if ($action[0] == 'shift') {
$s .= "\t\t'{$t}' => array( 0, {$action[1]} ),\n";
}
if ($action[0] == 'reduce') {
$s .= "\t\t'{$t}' => array( 1, {$action[1]} ),\n";
}
if ($action[0] == 'accept') {
$s .= "\t\t'{$t}' => array( 2, null ),\n";
}
}
$s .= "\t),\n";
}
$s .= ");\n\n";
$s .= "static \$goto = array(\n";
foreach ($this->mGoto as $id => $row) {
$body = $this->formatAssocArray($row);
$s .= "\t{$id} => {$body},\n";
}
$s .= ");\n\n";
$s .= "}\n";
return $s;
}
}
$definition = file_get_contents(dirname(__FILE__) . '/syntax.txt');
$grammar = Grammar::parse($definition);
$grammar->buildLRTable();
file_put_contents('LRTableBuildReport.html', $grammar->buildHTMLDump());
file_put_contents('LRTable.php', $grammar->buildPHPFile());
return "\f";
}), "ESCAPED_N" => new StringParser("\\n", function ($string) {
return "\n";
}), "ESCAPED_R" => new StringParser("\\r", function ($string) {
return "\r";
}), "ESCAPED_T" => new StringParser("\\t", function ($string) {
return "\t";
}), "ESCAPED_UTF8" => new RegexParser("#^\\\\u[0-9a-fA-F]{4}#", function ($match) {
return Utf8Parser::getBytes(hexdec(substr($match, 2, 4)));
})));
// if executing this file directly, run unit tests
if (__FILE__ !== $_SERVER["SCRIPT_FILENAME"]) {
return;
}
$start = microtime(true);
$parseTree = $jsonGrammar->parse(" { \"string\" : true, \"\\\"\" : false, \"\\u9874asdh\" : [ null, { }, -9488.44E+093 ] } ");
print "Parsing completed in " . (microtime(true) - $start) . " seconds\n";
var_dump(true);
// for successful parsing
// print_r($parseTree);
var_dump(count($parseTree) === 3);
var_dump($parseTree["string"] === true);
var_dump($parseTree["\""] === false);
var_dump($parseTree["顴asdh"] === array(null, array(), -9.488439999999999E+96));
print "2\n";
// failure modes
foreach (array("{ \"string ", "{ \"\\UAAAA\" ", "{ \"\\u000i\" ", "{ \"a\" : tru ", "{ \"a\" : +9 ", "{ \"a\" : 9. ", "{ \"a\" : 0a8.52 ", "{ \"a\" : 8E ", "{ \"a\" : 08 ", "[ \"a\" , 8 ]", " \"a\" ", "{\"\" :7}", "{\"\":7}", "{\"\n\" :7}", "{\"\r\" :7}", "{\"\t\" :7}") as $string) {
try {
$jsonGrammar->parse($string);
var_dump(false);
} catch (Exception $e) {
var_dump($parser->match("fff", 0) === array("j" => 2, "value" => array("f", "f")));
$parser = new GreedyMultiParser(new StringParser("f"), 1, null);
try {
$parser->match("", 0);
var_dump(false);
} catch (ParseFailureException $e) {
var_dump(true);
}
var_dump($parser->match("f", 0) === array("j" => 1, "value" => array("f")));
var_dump($parser->match("ff", 0) === array("j" => 2, "value" => array("f", "f")));
var_dump($parser->match("fff", 0) === array("j" => 3, "value" => array("f", "f", "f")));
var_dump($parser->match("ffg", 0) === array("j" => 2, "value" => array("f", "f")));
print "11\n";
$grammar = new Grammar("<A>", array("<A>" => new EmptyParser()));
try {
$grammar->parse("a");
var_dump(false);
} catch (ParseFailureException $e) {
var_dump(true);
}
var_dump($grammar->parse("") === null);
print "12A\n";
try {
$grammar = new Grammar("<S>", array("<S>" => new GreedyMultiParser("<A>", 7, null), "<A>" => new EmptyParser()));
var_dump(false);
} catch (GrammarException $e) {
var_dump(true);
}
try {
$grammar = new Grammar("<S>", array("<S>" => new GreedyStarParser("<A>"), "<A>" => new GreedyStarParser("<B>"), "<B>" => new EmptyParser()));
var_dump(false);
}), new StringParser("\""), "whitespace"), function ($quote1, $chars, $quote2, $whitespace) {
return new StringParser($chars);
}), "digit" => new RegexParser("#^[0-9]#"), "letter" => new RegexParser("#^[a-zA-Z]#"), "character" => new RegexParser("#^([^\"]|\"\")#", function ($match0) {
if ($match0 === "\"\"") {
return "\"";
}
return $match0;
}), "whitespace" => new RegexParser("#^[ \n\r\t]*#")), function ($syntax) {
$parsers = array();
foreach ($syntax as $production) {
if (count($parsers) === 0) {
$top = $production["identifier"];
}
$parsers[$production["identifier"]] = $production["expression"];
}
if (count($parsers) === 0) {
throw new Exception("No rules.");
}
return new Grammar($top, $parsers);
});
// if executing this file directly, run unit tests
if (__FILE__ !== $_SERVER["SCRIPT_FILENAME"]) {
return;
}
// This is the syntax for Wirth syntax notation except it lacks whitespace
$string = "\n\t\tSYNTAX = { PRODUCTION } .\n\t\tPRODUCTION = IDENTIFIER \"=\" EXPRESSION \".\" .\n\t\tEXPRESSION = TERM { \"|\" TERM } .\n\t\tTERM = FACTOR { FACTOR } .\n\t\tFACTOR = IDENTIFIER\n\t\t\t\t\t\t\t | LITERAL\n\t\t\t\t\t\t\t | \"[\" EXPRESSION \"]\"\n\t\t\t\t\t\t\t | \"(\" EXPRESSION \")\"\n\t\t\t\t\t\t\t | \"{\" EXPRESSION \"}\" .\n\t\tIDENTIFIER = letter { letter } .\n\t\tLITERAL = \"\"\"\" character { character } \"\"\"\" .\n\t\tdigit = \"0\" | \"1\" | \"2\" | \"3\" | \"4\" | \"5\" | \"6\" | \"7\" | \"8\" | \"9\" .\n\t\tupper = \"A\" | \"B\" | \"C\" | \"D\" | \"E\" | \"F\" | \"G\" | \"H\" | \"I\" | \"J\" \n\t\t | \"K\" | \"L\" | \"M\" | \"N\" | \"O\" | \"P\" | \"Q\" | \"R\" | \"S\" | \"T\" \n\t\t | \"U\" | \"V\" | \"W\" | \"X\" | \"Y\" | \"Z\" .\n\t\tlower = \"a\" | \"b\" | \"c\" | \"d\" | \"e\" | \"f\" | \"g\" | \"h\" | \"i\" | \"j\" \n\t\t | \"k\" | \"l\" | \"m\" | \"n\" | \"o\" | \"p\" | \"q\" | \"r\" | \"s\" | \"t\" \n\t\t | \"u\" | \"v\" | \"w\" | \"x\" | \"y\" | \"z\" .\n\t\tletter = upper | lower .\n\t\tcharacter = letter | digit | \"=\" | \".\" | \"\"\"\"\"\" .\n\t";
$wirthGrammar->parse($string)->parse("SYNTAX={PRODUCTION}.");
var_dump(true);
# for a successful parse
?>
}
$parsers[$rule["rule-name"]] = $rule["expression"];
}
if (count($parsers) === 0) {
throw new Exception("No rules.");
}
return new Grammar($top, $parsers);
});
// if executing this file directly, run unit tests
if (__FILE__ !== $_SERVER["SCRIPT_FILENAME"]) {
return;
}
// Full rule set
$string = "\n\t<postal-address> ::= <name-part> <street-address> <zip-part>\n\t<name-part> ::= <personal-part> <name-part> | <personal-part> <last-name> <opt-jr-part> <EOL>\n\t<personal-part> ::= <initial> \".\" | <first-name>\n\t<street-address> ::= <house-num> <street-name> <opt-apt-num> <EOL>\n\t<zip-part> ::= <town-name> \",\" <state-code> <ZIP-code> <EOL>\n\t<opt-jr-part> ::= \"Sr.\" | \"Jr.\" | <roman-numeral> | \"\"\n\n\t<last-name> ::= 'MacLaurin '\n\t<EOL> ::= '\n'\n\t<initial> ::= 'b'\n\t<first-name> ::= 'Steve '\n\t<house-num> ::= '173 '\n\t<street-name> ::= 'Acacia Avenue '\n\t<opt-apt-num> ::= '7A'\n\t<town-name> ::= 'Stevenage'\n\t<state-code> ::= ' KY '\n\t<ZIP-code> ::= '33445'\n\t<roman-numeral> ::= 'g'\n";
$start = microtime(true);
$grammar2 = $bnfGrammar->parse($string);
print "Parsing completed in " . (microtime(true) - $start) . " seconds\n";
$start = microtime(true);
$grammar2->parse("Steve MacLaurin \n173 Acacia Avenue 7A\nStevenage, KY 33445\n");
print "Parsing completed in " . (microtime(true) - $start) . " seconds\n";
$string = "\n\t<syntax> ::= <rule> | <rule> <syntax>\n\t<rule> ::= <opt-whitespace> \"<\" <rule-name> \">\" <opt-whitespace> \"::=\" <opt-whitespace> <expression> <line-end>\n\t<opt-whitespace> ::= \" \" <opt-whitespace> | \"\"\n\t<expression> ::= <list> | <list> \"|\" <expression>\n\t<line-end> ::= <opt-whitespace> <EOL> <line-end> | <opt-whitespace> <EOL>\n\t<list> ::= <term> | <term> <opt-whitespace> <list>\n\t<term> ::= <literal> | \"<\" <rule-name> \">\"\n\t<literal> ::= '\"' <text> '\"' | \"'\" <text> \"'\"\n\t\n\t<rule-name> ::= 'a'\n\t<EOL> ::= '\n'\n\t<text> ::= 'b'\n";
$start = microtime(true);
$grammar3 = $bnfGrammar->parse($string);
print "Parsing completed in " . (microtime(true) - $start) . " seconds\n";
$start = microtime(true);
$grammar3->parse(" <a> ::= 'b' \n");
print "Parsing completed in " . (microtime(true) - $start) . " seconds\n";
// Should raise a ParseFailureException before trying to instantiate a Grammar
$string = " <incomplete ::=";
try {
$bnfGrammar->parse($string);
}
$parsers[$rule["name"]] = $rule["lazyaltparser"];
}
return new Grammar($top, $parsers);
});
// if executing this file directly, run unit tests
if (__FILE__ !== $_SERVER["SCRIPT_FILENAME"]) {
return;
}
// parentheses inside your BNF *always* force an array to exist in the output
// *, +, ? and {m,n} are not disguised parentheses; they expand into the main expression
// in the absence of a function to call, an array is is built instead
print "0A\n";
// basic
// array("a") or new S("a")
$grammar2 = $locoGrammar->parse(" S ::= 'a' ");
var_dump($grammar2->parse("a") === array("a"));
// concatenation
// array("a", "b") or new S("a", "b")
$grammar2 = $locoGrammar->parse(" S ::= 'a' 'b' ");
var_dump($grammar2->parse("ab") === array("a", "b"));
// alternation
// array("a") or array("b") or new S("a") or new S("b")
$grammar2 = $locoGrammar->parse(" S ::= 'a' | 'b' ");
var_dump($grammar2->parse("a") === array("a"));
var_dump($grammar2->parse("b") === array("b"));
// alternation 2
// array("a") or array("b", "c") or new S("a") or new S("b", "c")
$grammar2 = $locoGrammar->parse(" S ::= 'a' | 'b' 'c' ");
var_dump($grammar2->parse("a") === array("a"));
var_dump($grammar2->parse("bc") === array("b", "c"));
if (count($parsers) === 0) {
$top = $rule["rule-name"];
}
$parsers[$rule["rule-name"]] = $rule["expression"];
}
if (count($parsers) === 0) {
throw new Exception("No rules.");
}
return new Grammar($top, $parsers);
});
// if executing this file directly, run unit tests
if (__FILE__ !== $_SERVER["SCRIPT_FILENAME"]) {
return;
}
$string = "a = 'PROGRAM' ;";
$ebnfGrammar->parse($string)->parse("PROGRAM");
var_dump(true);
// Should raise a ParseFailureException before trying to instantiate a Grammar
// with no rules and raising a GrammarException
$string = "a = 'PROGRAM ;";
try {
$ebnfGrammar->parse($string);
var_dump(false);
} catch (ParseFailureException $e) {
var_dump(true);
}
// Full rule set
$string = "\n\t\t(* a simple program syntax in EBNF - Wikipedia *)\n\t\tprogram = 'PROGRAM' , white space , identifier , white space ,\n\t\t\t\t\t\t\t 'BEGIN' , white space ,\n\t\t\t\t\t\t\t { assignment , \";\" , white space } ,\n\t\t\t\t\t\t\t 'END.' ;\n\t\tidentifier = alphabetic character , { alphabetic character | digit } ;\n\t\tnumber = [ \"-\" ] , digit , { digit } ;\n\t\tstring = '\"' , { all characters } , '\"' ;\n\t\tassignment = identifier , \":=\" , ( number | identifier | string ) ;\n\t\talphabetic character = \"A\" | \"B\" | \"C\" | \"D\" | \"E\" | \"F\" | \"G\"\n\t\t\t\t\t\t\t\t\t\t\t\t | \"H\" | \"I\" | \"J\" | \"K\" | \"L\" | \"M\" | \"N\"\n\t\t\t\t\t\t\t\t\t\t\t\t | \"O\" | \"P\" | \"Q\" | \"R\" | \"S\" | \"T\" | \"U\"\n\t\t\t\t\t\t\t\t\t\t\t\t | \"V\" | \"W\" | \"X\" | \"Y\" | \"Z\" ;\n\t\tdigit = \"0\" | \"1\" | \"2\" | \"3\" | \"4\" | \"5\" | \"6\" | \"7\" | \"8\" | \"9\" ;\n\t\twhite space = ( \" \" | \"\n\" ) , { \" \" | \"\n\" } ;\n\t\tall characters = \"H\" | \"e\" | \"l\" | \"o\" | \" \" | \"w\" | \"r\" | \"d\" | \"!\" ;\n\t";
$pascalGrammar = $ebnfGrammar->parse($string);
var_dump(true);
$string = "PROGRAM DEMO1\n" . "BEGIN\n" . " A0:=3;\n" . " B:=45;\n" . " H:=-100023;\n" . " C:=A;\n" . " D123:=B34A;\n" . " BABOON:=GIRAFFE;\n" . " TEXT:=\"Hello world!\";\n" . "END.";
# This code is in the public domain.
# http://qntm.org/loco
$simpleCommentGrammar = new Grammar("<comment>", array("<comment>" => new GreedyStarParser("<blockorwhitespace>", function () {
return implode("", func_get_args());
}), "<blockorwhitespace>" => new LazyAltParser(array("<h5>", "<p>", "WHITESPACE")), "<p>" => new ConcParser(array("OPEN_P", "<text>", "CLOSE_P"), function ($open_p, $text, $close_p) {
return $open_p . $text . $close_p;
}), "<h5>" => new ConcParser(array("OPEN_H5", "<text>", "CLOSE_H5"), function ($open_h5, $text, $close_h5) {
return $open_h5 . $text . $close_h5;
}), "<strong>" => new ConcParser(array("OPEN_STRONG", "<text>", "CLOSE_STRONG"), function ($open_strong, $text, $close_strong) {
return $open_strong . $text . $close_strong;
}), "<em>" => new ConcParser(array("OPEN_EM", "<text>", "CLOSE_EM"), function ($open_em, $text, $close_em) {
return $open_em . $text . $close_em;
}), "<text>" => new GreedyStarParser("<atom>", function () {
return implode("", func_get_args());
}), "<atom>" => new LazyAltParser(array("<char>", "<strong>", "<em>", "FULL_BR")), "<char>" => new LazyAltParser(array("UTF8_EXCEPT", "GREATER_THAN", "LESS_THAN", "AMPERSAND")), "WHITESPACE" => new RegexParser("#^[ \n\r\t]+#"), "OPEN_P" => new RegexParser("#^<p[ \n\r\t]*>#"), "CLOSE_P" => new RegexParser("#^</p[ \n\r\t]*>#"), "OPEN_H5" => new RegexParser("#^<h5[ \n\r\t]*>#"), "CLOSE_H5" => new RegexParser("#^</h5[ \n\r\t]*>#"), "OPEN_EM" => new RegexParser("#^<em[ \n\r\t]*>#"), "CLOSE_EM" => new RegexParser("#^</em[ \n\r\t]*>#"), "OPEN_STRONG" => new RegexParser("#^<strong[ \n\r\t]*>#"), "CLOSE_STRONG" => new RegexParser("#^</strong[ \n\r\t]*>#"), "FULL_BR" => new RegexParser("#^<br[ \n\r\t]*/>#"), "UTF8_EXCEPT" => new Utf8Parser(array("<", ">", "&")), "GREATER_THAN" => new StringParser(">"), "LESS_THAN" => new StringParser("<"), "AMPERSAND" => new StringParser("&")));
// if executing this file directly, run unit tests
if (__FILE__ !== $_SERVER["SCRIPT_FILENAME"]) {
return;
}
$start = microtime(true);
$string = $simpleCommentGrammar->parse("<h5> Title<br /><em\n><strong\n></strong>&</em></h5> \r\n\t <p ><</p >");
print "Parsing completed in " . (microtime(true) - $start) . " seconds\n";
var_dump($string === "<h5> Title<br /><em\n><strong\n></strong>&</em></h5> \r\n\t <p ><</p >");
foreach (array("<h5 style=\"\">", "&", "<", "salkhsfg>", "</p", "<br") as $string) {
try {
$simpleCommentGrammar->parse($string);
var_dump(false);
} catch (Exception $e) {
var_dump(true);
}
}
}
public function __toString()
{
return implode("", $this->mults);
}
}
// Each Pattern is an alternation between several "Concs"
// This is the top-level Pattern object returned by the lexer.
class Pattern
{
public $concs;
public function __construct($concs)
{
foreach ($concs as $conc) {
if (!is_a($conc, "Conc")) {
throw new Exception("Not a Conc: " . var_export($conc, true));
}
}
$this->concs = $concs;
}
public function __toString()
{
return implode("|", $this->concs);
}
}
// apologies for the relative lack of exhaustive unit tests
foreach (array("a{2}", "a{2,}", "a{2,8}", "[\$%\\^]{2,8}", "[ab]*", "([ab]*a)", "([ab]*a|[bc]*c)", "([ab]*a|[bc]*c)?", "([ab]*a|[bc]*c)?b*", "[a-zA-Z]", "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789", "[a]", "[abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789]", "[|(){},?*+\\[\\]\\^.\\\\]", "[\\f\\n\\r\\t\\v\\-]", "\\|", "\\(\\)\\{\\},\\?\\*\\+\\[\\]^.-\\f\\n\\r\\t\\v\\w\\d\\s\\W\\D\\S\\\\", "abcdef", "19\\d\\d-\\d\\d-\\d\\d", "[\$%\\^]{2,}", "[\$%\\^]{2}", "") as $string) {
$pattern = $regexGrammar->parse($string);
print $pattern . "\n";
var_dump(true);
}
