PHP code example of flaviovs / phpast

    
        
<?php
require_once('vendor/autoload.php');

/* Start to develop here. Best regards https://php-download.com/ */

    

flaviovs / phpast example snippets

$my_autoloader->addPSR4('PHPAST', 'path/to/phpast/src');

// First, create a symbol table for our "program".
$table = new PHPAST\FlatSymbolTable();

// Our "program" will contain only the integer value 1. It is very dumb, so
// once it is run (evaluated), it should just return the same integer value.
$program = new PHPAST\Integer(1);

// Now let's run our program
$output = $program->evaluate($table);

$table = new PHPAST\FlatSymbolTable();

// Lets' define some values
$number1 = new PHPAST\Integer(2);
$number2 = new PHPAST\Integer(4);

// Our program now will multiply the two integers.
$program = new PHPAST\MulOp($number1, $number2);

// Now let's run our program
$output = $program->evaluate($table);

$number1 = new PHPAST\Integer(2);
$number2 = new PHPAST\Integer(4);

// Our program now will multiply the two integers.
$program = new PHPAST\MulOp(
	new PHPAST\AddOp($number1, $number2),
	new PHPAST\SubOp($number1, $number2)
);

// Now let's run our program
$output = $program->evaluate($table);

$table = new PHPAST\FlatSymbolTable();
$table['foo'] = new PHPAST\String('bar');
$table['launch'] = PHPAST\Boolean::getFalse();

if ($table['launch'] === PHPAST\Boolean::getTrue()) {
    print "Launch\n";
}

use PHPAST\FlatSymbolTable;
use PHPAST\Integer;
use PHPAST\Float;
use PHPAST\Ref;
use PHPAST\Identifier;
use PHPAST\AssignOp;
use PHPAST\PowerOp;
use PHPAST\Outln;

// Create and initialize a symbol table.
$table = new FlatSymbolTable(['foo' => new Float(0)]);

// Create a 'foo' identifier. Identifiers work pretty much like as an ordinary
// string value. All variable reference must be done using identifiers, so we
// here we create one.
$foo_id = new Identifier('foo');

// Now create a reference to the variable.
$foo_ref = new Ref($foo_id);

// This program will assign Float(3.14159) to 'foo'. This would be the
// equivalent of the following construct in PHP:
//
//    $foo = 3.14159;
$program = new AssignOp($foo_ref, new Float(3.14159));

// Now let's run our program.
$program->evaluate($table);

// This should print the 'foo' entry in the symbol table with the value 3.14159.
print_r($table['foo']);

// $bar = $foo ** 2
$bar_ref = new Ref(new Identifier('bar'));
$program = new AssignOp($bar_ref, new PowerOp($foo_ref, new Integer(2)));
$program->evaluate($table);

// Let's use the Outln operation to print the newly created 'bar' variable.
// This should print "3.14159 to the power of two is 9.8695877281".
$program  = new Outln([
	                      $foo_ref,
	                      " to the power of two is ",
	                      $bar_ref,
                      ]);
$program->evaluate($table);

$table = new FlatSymbolTable(['foo' => new Float(0)]);
$foo_ref = new Ref(new Identifier('foo'));
$program = new Outln([
	                     new PowerOp(new Float(3.14159),
	                                 new Integer(2)),
                     ]);
print "$program\n";

$foo_ref = new Ref(new Identifier('foo'));
$bar_ref = new Ref(new Identifier('bar'));
$prog = new Prog();

// $foo = 0;
// $bar = 1;
$prog[] = new AssignOp($foo_ref, new Integer(0));
$prog[] = new AssignOp($bar_ref, new Integer(1));

// $bar += 10
$prog[] = new IncOp($foo_ref, 10);

// for(;$foo > $bar; $foo -= 2) { print "foo = $foo\n"; }
$prog[] = new ForOp(new Nop(),
                    new GtOp($foo_ref, $bar_ref),
                    new DecOp($foo_ref, 2),
                    new Outln([ "foo = ", $foo_ref ]));

print "$prog\n";