File modules/dsl/ast/DslStatementList.class.php

Last commit: Tue Jul 19 00:10:00 2022 +0200	Jan Dankert	New: Scripting language: Ignore Keyword "new"; Support for Calling object constructors; Splitting objects into an instance and a wrapper.


     1 <?php
     2 
     3 namespace dsl\ast;
     4 
     5 use dsl\DslParserException;
     6 use dsl\DslToken;
     7 
     8 class DslStatementList extends DslElement implements DslStatement
     9 {
    10 	private $statements = [];
    11 
    12 	private $functions = [];
    13 
    14 	public function __construct($tokenList)
    15 	{
    16 		$this->parse($tokenList);
    17 	}
    18 
    19 	/**
    20 	 * @param $tokens DslToken[]
    21 	 * @throws DslParserException
    22 	 */
    23 	public function parse($tokens)
    24 	{
    25 		$this->parseTokens($tokens);
    26 	}
    27 
    28 	public function execute( & $context)
    29 	{
    30 		// Auto hoisting for functions: Add functions to context.
    31 		$context = array_merge( $context, $this->functions );
    32 
    33 		foreach ($this->statements as $statement) {
    34 
    35 			$value = $statement->execute($context);
    36 
    37 			if ($statement instanceof DslReturn)
    38 				return $value; // Return to the caller
    39 		}
    40 
    41 		return null;
    42 	}
    43 
    44 
    45 
    46 	/**
    47 	 * @param $tokens DslToken[]
    48 	 * @throws DslParserException
    49 	 */
    50 	public function parseTokens($tokens)
    51 	{
    52 		while (true) {
    53 			$token = array_shift($tokens);
    54 
    55 			if   ( ! $token )
    56 				return;
    57 
    58 			switch ($token->type) {
    59 
    60 				case DslToken::T_STATEMENT_END:
    61 					// maybe an empty statement?
    62 					break;
    63 
    64 				case DslToken::T_OPERATOR:
    65 					throw new DslParserException('Unexpected operator', $token->lineNumber);
    66 				case DslToken::T_BRACKET_CLOSE:
    67 					throw new DslParserException('Unexpected closing group', $token->lineNumber);
    68 				case DslToken::T_BLOCK_END:
    69 					throw new DslParserException('Unexpected ending of an block', $token->lineNumber);
    70 				case DslToken::T_NEGATION:
    71 					throw new DslParserException('Unexpected negation', $token->lineNumber);
    72 				case DslToken::T_DOT:
    73 					throw new DslParserException('Unexpected dot', $token->lineNumber);
    74 
    75 				case DslToken::T_FUNCTION:
    76 
    77 					$nameToken = array_shift( $tokens );
    78 					if ($nameToken->type != DslToken::T_STRING)
    79 						throw new DslParserException('function must have a name', $token->lineNumber);
    80 					$name = $nameToken->value;
    81 
    82 					$functionCallOp    = array_shift($tokens);
    83 					if   ( $functionCallOp->type != DslToken::T_OPERATOR || $functionCallOp->value != '$' )
    84 						throw new DslParserException('function \''.$name.'\' must have a function signature');
    85 
    86 					$functionParameter = $this->getGroup($tokens);
    87 					$functionBlock     = $this->getBlock($tokens);
    88 
    89 					$this->functions[ $name ] = new DslFunction( $functionParameter, $functionBlock );
    90 
    91 					break;
    92 
    93 				case DslToken::T_IF:
    94 					$condition = $this->getGroup($tokens);
    95 					$positiveBlock = $this->getStatementOrBlock($tokens);
    96 					$nextToken = array_shift($tokens);
    97 					if ($nextToken && $nextToken->type == DslToken::T_ELSE) {
    98 						$negativeBlock = $this->getStatementOrBlock($tokens);
    99 					} else {
   100 						$negativeBlock = [];
   101 						array_unshift($tokens, $nextToken);
   102 					}
   103 					$this->statements[] = new DslIf($condition, $positiveBlock, $negativeBlock);
   104 					break;
   105 
   106 				case DslToken::T_NEW:
   107 				case DslToken::T_LET:
   108 					break; // ignore these statements
   109 
   110 				case DslToken::T_NULL:
   111 					$this->statements[] = new DslNull();
   112 					break;
   113 
   114 				case DslToken::T_TRUE:
   115 					$this->statements[] = new DslTrue();
   116 					break;
   117 
   118 				case DslToken::T_FALSE:
   119 					$this->statements[] = new DslFalse();
   120 					break;
   121 
   122 				case DslToken::T_FOR:
   123 					$forGroup = $this->getGroup( $tokens );
   124 					$forBlock = $this->getStatementOrBlock( $tokens );
   125 
   126 					//echo "<h5>Forgroup:</h5><pre>"; var_export( $forGroup); echo "</pre>";
   127 
   128 					$varName = array_shift( $forGroup );
   129 					if   ( $varName == null || $varName->type != DslToken::T_STRING )
   130 						throw new DslParserException('for loop variable missing');
   131 					$ofName = array_shift( $forGroup );
   132 					if   ( $ofName == null || $ofName->type != DslToken::T_STRING || strtolower($ofName->value) != 'of' )
   133 						throw new DslParserException('missing \'of\' in for loop');
   134 
   135 					$this->statements[] = new DslFor( $varName->value, $forGroup, $forBlock );
   136 					break;
   137 
   138 				case DslToken::T_RETURN:
   139 					$returnTokens = $this->getSingleStatement( $tokens );
   140 					$this->statements[] = new DslReturn( $returnTokens );
   141 					break;
   142 
   143 				case DslToken::T_THROW:
   144 					$returnTokens = $this->getSingleStatement($tokens );
   145 					$this->statements[] = new DslThrow( $returnTokens );
   146 					break;
   147 
   148 				case DslToken::T_TEXT:
   149 				case DslToken::T_NUMBER:
   150 				case DslToken::T_STRING:
   151 					array_unshift( $tokens, $token );
   152 					$statementTokens = $this->getSingleStatement( $tokens );
   153 
   154 					$this->statements[] = new DslExpression( $statementTokens );
   155 					break;
   156 
   157 				default:
   158 					throw new DslParserException('Unknown token of type '.$token->type,$token->lineNumber );
   159 			}
   160 
   161 		}
   162 
   163 	}
   164 
   165 
   166 }



Download modules/dsl/ast/DslStatementList.class.php


History
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.
Sun, 26 Jun 2022 15:46:54 +0200	Jan Dankert	Fix: Another, little better, hack for parameterless functions. Shunting yard seems to be unable to handle empty parentheses.
Tue, 7 Jun 2022 23:30:20 +0200	Jan Dankert	New: DSL is now supporting throw statements.
Mon, 6 Jun 2022 13:35:56 +0200	Jan Dankert	Change: Completely ignoring let,var,const statements.
Wed, 1 Jun 2022 00:11:40 +0200	Jan Dankert	New: DSL as a filter for number values
Sun, 29 May 2022 16:56:40 +0200	Jan Dankert	New: DSL with support for functions with return values, full arithmetic, object properties
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, ...
Wed, 25 May 2022 22:47:17 +0200	Jan Dankert	New: DSL (domain specific language) for code elements. The old way with PHP code ist not sandboxed and unsecure. This approach is a minimalistic, javascript-like, scripting engine. For now only simple function calls are possible, for example: alert("example");