File modules/dsl/executor/DslInterpreter.class.php

Last commit: Fri Feb 17 02:02:18 2023 +0100	Jan Dankert	Refactoring: Script-context should be the same in all environments; New: DslPdf for creating PDF with scriptbox ;)


     1 <?php
     2 
     3 namespace dsl\executor;
     4 
     5 use dsl\DslAstParser;
     6 use dsl\DslException;
     7 use dsl\DslLexer;
     8 use dsl\DslRuntimeException;
     9 use dsl\standard\ArrayWrapper;
    10 use dsl\standard\NumberInstance;
    11 use dsl\standard\NumberWrapper;
    12 use dsl\standard\Script;
    13 use dsl\standard\ArrayInstance;
    14 use dsl\standard\DateWrapper;
    15 use dsl\standard\MathWrapper;
    16 use dsl\standard\StringInstance;
    17 use dsl\standard\StringWrapper;
    18 use dsl\standard\System;
    19 use dsl\standard\Writer;
    20 use dsl\standard\WriteWrapper;
    21 
    22 class DslInterpreter
    23 {
    24 	/**
    25 	 * Execution context.
    26 	 *
    27 	 * @var array
    28 	 */
    29 	private $context = [];
    30 
    31 	/**
    32 	 * Holds a reference to the write()-Function for getting the output buffer after execution.
    33 	 * @var Writer
    34 	 */
    35 	private $writer;
    36 	private $flags;
    37 
    38 	const FLAG_SHOW_ERROR  =  1;
    39 	const FLAG_SHOW_TRACE  =  2;
    40 	const FLAG_THROW_ERROR =  4;
    41 	const FLAG_DEBUG       =  8;
    42 	const FLAG_SECURE      = 16;
    43 
    44 	private static $secure = true;
    45 
    46 	public function __construct( $flags = self::FLAG_SHOW_ERROR + self::FLAG_SECURE )
    47 	{
    48 		$this->flags = $flags;
    49 
    50 		self::$secure = boolval($this->flags & self::FLAG_SECURE );
    51 
    52 		$this->addStandardContext();
    53 	}
    54 
    55 	/**
    56 	 * adds an external context to the interpreter environment.
    57 	 *
    58 	 * @param $context []
    59 	 */
    60 	public function addContext($context ) {
    61 		$this->context = array_merge( $this->context, $context );
    62 	}
    63 
    64 
    65 	/**
    66 	 * Parses and runs the DSL code.
    67 	 *
    68 	 * @param $code String Script-Code
    69 	 * @throws DslException
    70 	 * @return mixed value of last return statement (if any)
    71 	 */
    72 	public function runCode( $code ) {
    73 
    74 		// Step 1: Splitting the source code into tokens (the "Lexer")
    75 		$lexer = new DslLexer();
    76 		$token = $lexer->tokenize( $code );
    77 
    78 		// Step 2: Creating a syntax tree (abstract syntax tree, AST).
    79 		try {
    80 
    81 			$parser = new DslAstParser();
    82 			$parser->parse( $token );
    83 
    84 			//if   ( $this->flags & self::FLAG_DEBUG )
    85 			// it has no security impact, so lets do it always.
    86 				$this->addContext(
    87 					[ 'Script' => new Script( $token,$parser->rootStatement ) ]
    88 				);
    89 
    90 			// Step 3: Executing the syntax tree.
    91 			return $parser->execute( $this->context );
    92 		} catch ( \Exception $e ) {
    93 			if   ( $this->flags & self::FLAG_SHOW_ERROR ) {
    94 				if   ( $this->flags & self::FLAG_SHOW_TRACE )
    95 					$this->writer->buffer .= $e->__toString();
    96 				else
    97 					$this->writer->buffer .= $e->getMessage();
    98 			}
    99 			if   ( $this->flags & self::FLAG_THROW_ERROR )
   100 				throw new DslRuntimeException('Script runtime error',0,$e);
   101 		}
   102 	}
   103 
   104 
   105 	/**
   106 	 * Gets the output which was written by the code.
   107 	 *
   108 	 * @return mixed
   109 	 */
   110 	public function getOutput() {
   111 
   112 		return $this->writer->buffer;
   113 	}
   114 
   115 	/**
   116 	 * @return bool
   117 	 */
   118 	public static function isSecure() {
   119 		return self::$secure;
   120 	}
   121 
   122 	/**
   123 	 * Adding the standard context.
   124 	 *
   125 	 * @return void
   126 	 */
   127 	private function addStandardContext()
   128 	{
   129 		// Standard-Globals
   130 		$this->addContext( [
   131 
   132 			// Standard JS objects
   133 			'Math'   => new MathWrapper(),
   134 			'Array'  => new ArrayWrapper(),
   135 			'String' => new StringWrapper(),
   136 			'Number' => new NumberWrapper(),
   137 			'Date'   => new DateWrapper(),
   138 
   139 			// Custom Scriptbox objects
   140 			'System'  => new System(),
   141 			'write'   => $this->writer = new Writer(),
   142 			'writeln' => new WriteWrapper( $this->writer,"\n" ),
   143 			'print'   => new WriteWrapper( $this->writer,'' ),
   144 			'println' => new WriteWrapper( $this->writer,"\n" ),
   145 		] );
   146 	}
   147 }



Download modules/dsl/executor/DslInterpreter.class.php


History
Fri, 17 Feb 2023 02:02:18 +0100	Jan Dankert	Refactoring: Script-context should be the same in all environments; New: DslPdf for creating PDF with scriptbox ;)
Tue, 19 Jul 2022 00:10:00 +0200	Jan Dankert	New: Scripting language: Ignore Keyword "new"; Support for Calling object constructors; Splitting objects into an instance and a wrapper.
Fri, 1 Jul 2022 18:09:05 +0200	Jan Dankert	New: Bugfixes and much more string and array functions for the DSL.
Mon, 27 Jun 2022 01:11:02 +0200	Jan Dankert	New: Secure Flag for Script Interpreter which is enabled by default.
Mon, 27 Jun 2022 00:40:42 +0200	Jan Dankert	New: Marker interface 'Scriptable', Proxy class for MQTT, help() method in Scripts.
Sun, 26 Jun 2022 12:51:07 +0200	Jan Dankert	New: DSL can be controlled by flags; support for error messages; support for negativ numbers.
Thu, 2 Jun 2022 01:50:05 +0200	Jan Dankert	Refactoring: DSL Interpreter is now using a write buffer
Wed, 1 Jun 2022 00:11:40 +0200	Jan Dankert	New: DSL as a filter for number values
Sun, 29 May 2022 01:13:27 +0200	Jan Dankert	New: DSL with support for functions
Sat, 28 May 2022 18:00:13 +0200	Jan Dankert	New: DSL with a much better syntax parsing and support for assignments, conditions, ...