function ctools_math_expr::evaluate in Chaos Tool Suite (ctools) 6

Same name and namespace in other branches

1. 7 includes/math-expr.inc \ctools_math_expr::evaluate()

1 call to ctools_math_expr::evaluate()

ctools_math_expr::e in includes/math-expr.inc

File

includes/math-expr.inc, line 112

Class

ctools_math_expr

Code

function evaluate($expr) {
  $this->last_error = null;
  $expr = trim($expr);
  if (substr($expr, -1, 1) == ';') {
    $expr = substr($expr, 0, strlen($expr) - 1);
  }

  // strip semicolons at the end

  //===============

  // is it a variable assignment?
  if (preg_match('/^\\s*([a-z]\\w*)\\s*=\\s*(.+)$/', $expr, $matches)) {
    if (in_array($matches[1], $this->vb)) {

      // make sure we're not assigning to a constant
      return $this
        ->trigger("cannot assign to constant '{$matches[1]}'");
    }
    if (($tmp = $this
      ->pfx($this
      ->nfx($matches[2]))) === false) {
      return false;
    }

    // get the result and make sure it's good
    $this->v[$matches[1]] = $tmp;

    // if so, stick it in the variable array
    return $this->v[$matches[1]];

    // and return the resulting value

    //===============

    // is it a function assignment?
  }
  elseif (preg_match('/^\\s*([a-z]\\w*)\\s*\\(\\s*([a-z]\\w*(?:\\s*,\\s*[a-z]\\w*)*)\\s*\\)\\s*=\\s*(.+)$/', $expr, $matches)) {
    $fnn = $matches[1];

    // get the function name
    if (in_array($matches[1], $this->fb)) {

      // make sure it isn't built in
      return $this
        ->trigger("cannot redefine built-in function '{$matches[1]}()'");
    }
    $args = explode(",", preg_replace("/\\s+/", "", $matches[2]));

    // get the arguments
    if (($stack = $this
      ->nfx($matches[3])) === false) {
      return false;
    }

    // see if it can be converted to postfix
    for ($i = 0; $i < count($stack); $i++) {

      // freeze the state of the non-argument variables
      $token = $stack[$i];
      if (preg_match('/^[a-z]\\w*$/', $token) and !in_array($token, $args)) {
        if (array_key_exists($token, $this->v)) {
          $stack[$i] = $this->v[$token];
        }
        else {
          return $this
            ->trigger("undefined variable '{$token}' in function definition");
        }
      }
    }
    $this->f[$fnn] = array(
      'args' => $args,
      'func' => $stack,
    );
    return true;

    //===============
  }
  else {
    return $this
      ->pfx($this
      ->nfx($expr));

    // straight up evaluation, woo
  }
}