params = $params; $this->precision = $precision; $this->precision_mode = $precision_mode; $f = $this->replace_parenth($formula, 0); if(strrpos($f, ')')>-1) { $this->parse_error = 'PARSING ERROR: Too many closing parenthesis !'; return(false); } $this->tree = $this->parse($f); } private function do_single_op($op, $x){ switch($op){ case '+': return($x); case '-': return(-$x); } } private function do_dual_op($x, $op, $y){ switch($op){ case '+': return($x+$y); case '-': return($x-$y); case '*': return($x*$y); case '/': return($x/$y); case '%': return($x%$y); case '^': return($x**$y); } } private function find_closingp($f, $i0){ if(substr($f,$i0,1)!='(') return(false); $level = 0; for($i=$i0+1;$idual_lp_ops, $this->dual_hp_ops, $this->single_ops); $nf=''; for($i=0;$ifind_closingp($f, $i); if($closing_idx===false) { $this->parse_error = "PARSING ERROR: missing closing parenthesis !"; return(''); } $expr = substr($f, $i+1, $closing_idx-$i-1); $expr_name = 'expr_'.$expr_index++; $nf.=$expr_name; $this->params[$expr_name] = $this->replace_parenth($expr, $expr_index); $i = $closing_idx; // let the loop do the +1 } else { $nf .= $c; } } return($nf); } private function parse($f){ //echo('

Parsing:'.$f.'

'); $re = '/^(.+?)([\\'.implode('\\',$this->dual_lp_ops).'])(.+)$/'; // dual low priority op if(preg_match($re, $f, $matches, PREG_OFFSET_CAPTURE, 0)){ $recur = $this->parse($matches[3][0]); if($recur!==false) return([$this->parse($matches[1][0]), $matches[2][0], $recur]); else return(false); } else { $re = '/^(.+?)([\\'.implode('\\',$this->dual_hp_ops).'])(.+)$/'; // dual high priority op if(preg_match($re, $f, $matches, PREG_OFFSET_CAPTURE, 0)){ $recur = $this->parse($matches[3][0]); if($recur!==false) return([$this->parse($matches[1][0]), $matches[2][0], $recur]); else return(false); } else { $re = '/^([\\'.implode('\\',$this->single_ops).'])(.+)$/'; // single op if(preg_match($re, $f, $matches, PREG_OFFSET_CAPTURE, 0)){ $recur = $this->parse($matches[2][0]); if($recur!==false) return([null, $matches[1][0], $recur]); else return(false); } else { $re1 = '/^([A-Za-z][A-Za-z0-9_]*)\[\"([A-Za-z0-9_]+)\"\]$/'; // arrays with alphanum keys $re2 = "/^([A-Za-z][A-Za-z0-9_]*)\[\'([A-Za-z0-9_]+)\'\]$/"; // arrays with alphanum keys if(preg_match($re1, $f, $matches1, PREG_OFFSET_CAPTURE, 0)||preg_match($re2, $f, $matches2, PREG_OFFSET_CAPTURE, 0)){ $array_name = (count($matches1)>0) ? $matches1[1][0] : $matches2[1][0]; $array_key = (count($matches1)>0) ? $matches1[2][0] : $matches2[2][0]; if(array_key_exists($array_name, $this->params) && is_array($this->params[$array_name])) { if(array_key_exists($array_key, $this->params[$array_name])) { return($this->parse($this->params[$array_name][$array_key])); } else { $this->parse_error = 'PARSING ERROR: Unknown key "'.$array_key.'" for array "'.$array_name.'" '; return(false); } } else { $this->parse_error = 'PARSING ERROR: Unknown array "'.$array_name.'" '; return(false); } } else { $re = '/^([A-Za-z][A-Za-z0-9_]*)\[(\d+)\]$/'; // arrays with alphanum keys if(preg_match($re, $f, $matches, PREG_OFFSET_CAPTURE, 0)){ $array_name = $matches[1][0]; $array_index = $matches[2][0]; if(array_key_exists($array_name, $this->params) && is_array($this->params[$array_name])) { if(isset($this->params[$array_name][$array_index])) { return($this->parse($this->params[$array_name][$array_index])); } else { $this->parse_error = 'PARSING ERROR: Unknown index "'.$array_index.'" for array "'.$array_name.'" '; return(false); } } else { $this->parse_error = 'PARSING ERROR: Unknown array "'.$array_name.'" '; return(false); } } else { $re = '/^([A-Za-z][A-Za-z0-9_]*)$/'; // simple variables if(preg_match($re, $f, $matches, PREG_OFFSET_CAPTURE, 0)){ if(array_key_exists($matches[0][0], $this->params)) return($this->parse($this->params[$matches[0][0]])); else { $this->parse_error = 'PARSING ERROR: Unknown expression "'.$matches[0][0].'" '; return(false); } } else { $re = '/^\d*(\.\d+)?$/'; // unsigned float or int if(preg_match($re, $f, $matches, PREG_OFFSET_CAPTURE, 0)){ return($matches[0][0]); } else { $this->parse_error = 'PARSING ERROR at '.$f.'
'; return(false); } } } } } } } } private function comp($t) { if(!is_array($t)) return($t); if($t[0]===null) { //unary op return($this->do_single_op($t[1],$this->comp($t[2]))); } else { return($this->do_dual_op($this->comp($t[0]), $t[1],$this->comp($t[2]))); } } public function compute(){ if($this->precision === null) return($this->comp($this->tree)); else return(round($this->comp($this->tree),$this->precision, $this->precision_mode)); } }