diff --git a/lib/evalmath/evalmath.class.php b/lib/evalmath/evalmath.class.php
index 0b0417c2be0..84a74488b6d 100644
--- a/lib/evalmath/evalmath.class.php
+++ b/lib/evalmath/evalmath.class.php
@@ -1,484 +1,484 @@
-<?php
-
-/*
-================================================================================
-
-EvalMath - PHP Class to safely evaluate math expressions
-Copyright (C) 2005 Miles Kaufmann <http://www.twmagic.com/>
-
-================================================================================
-
-NAME
- EvalMath - safely evaluate math expressions
-
-SYNOPSIS
- <?
- include('evalmath.class.php');
- $m = new EvalMath;
- // basic evaluation:
- $result = $m->evaluate('2+2');
- // supports: order of operation; parentheses; negation; built-in functions
- $result = $m->evaluate('-8(5/2)^2*(1-sqrt(4))-8');
- // create your own variables
- $m->evaluate('a = e^(ln(pi))');
- // or functions
- $m->evaluate('f(x,y) = x^2 + y^2 - 2x*y + 1');
- // and then use them
- $result = $m->evaluate('3*f(42,a)');
- ?>
-
-DESCRIPTION
- Use the EvalMath class when you want to evaluate mathematical expressions
- from untrusted sources. You can define your own variables and functions,
- which are stored in the object. Try it, it's fun!
-
-METHODS
- $m->evalute($expr)
- Evaluates the expression and returns the result. If an error occurs,
- prints a warning and returns false. If $expr is a function assignment,
- returns true on success.
-
- $m->e($expr)
- A synonym for $m->evaluate().
-
- $m->vars()
- Returns an associative array of all user-defined variables and values.
-
- $m->funcs()
- Returns an array of all user-defined functions.
-
-PARAMETERS
- $m->suppress_errors
- Set to true to turn off warnings when evaluating expressions
-
- $m->last_error
- If the last evaluation failed, contains a string describing the error.
- (Useful when suppress_errors is on).
-
-AUTHOR INFORMATION
- Copyright 2005, Miles Kaufmann.
-
-LICENSE
- Redistribution and use in source and binary forms, with or without
- modification, are permitted provided that the following conditions are
- met:
-
- 1 Redistributions of source code must retain the above copyright
- notice, this list of conditions and the following disclaimer.
- 2. Redistributions in binary form must reproduce the above copyright
- notice, this list of conditions and the following disclaimer in the
- documentation and/or other materials provided with the distribution.
- 3. The name of the author may not be used to endorse or promote
- products derived from this software without specific prior written
- permission.
-
- THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
- IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
- WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
- INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
- (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
- SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
- STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
- ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- POSSIBILITY OF SUCH DAMAGE.
-
-*/
-
-/**
- * This class was heavily modified in order to get usefull spreadsheet emulation ;-)
- * skodak
- *
- */
-
-class EvalMath {
-
- var $suppress_errors = false;
- var $last_error = null;
-
- var $v = array(); // variables (and constants)
- var $f = array(); // user-defined functions
- var $vb = array(); // constants
- var $fb = array( // built-in functions
- 'sin','sinh','arcsin','asin','arcsinh','asinh',
- 'cos','cosh','arccos','acos','arccosh','acosh',
- 'tan','tanh','arctan','atan','arctanh','atanh',
- 'sqrt','abs','ln','log','exp');
-
- var $fc = array( // calc functions emulation
- 'average'=>array(-1), 'max'=>array(-1), 'min'=>array(-1),
- 'mod'=>array(2), 'pi'=>array(0), 'power'=>array(2),
- 'round'=>array(1, 2), 'sum'=>array(-1));
-
- function EvalMath() {
- }
-
- function e($expr) {
- return $this->evaluate($expr);
- }
-
- function evaluate($expr) {
- $this->last_error = null;
- $expr = trim($expr);
- if (substr($expr, -1, 1) == ';') $expr = substr($expr, 0, strlen($expr)-1); // strip semicolons at the end
- //===============
- // is it a variable assignment?
- if (preg_match('/^\s*([a-z][a-z0-9]*)\s*=\s*(.+)$/', $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][a-z0-9]*)\s*\(\s*([a-z][a-z0-9]*(?:\s*,\s*[a-z][a-z0-9]*)*)\s*\)\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][a-z0-9]*$/', $token) and !in_array($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
- }
- }
-
- function vars() {
- return $this->v;
- }
-
- function funcs() {
- $output = array();
- foreach ($this->f as $fnn=>$dat)
- $output[] = $fnn . '(' . implode(',', $dat['args']) . ')';
- return $output;
- }
-
- //===================== HERE BE INTERNAL METHODS ====================\\
-
- // Convert infix to postfix notation
- function nfx($expr) {
-
- $index = 0;
- $stack = new EvalMathStack;
- $output = array(); // postfix form of expression, to be passed to pfx()
- $expr = trim(strtolower($expr));
-
- $ops = array('+', '-', '*', '/', '^', '_');
- $ops_r = array('+'=>0,'-'=>0,'*'=>0,'/'=>0,'^'=>1); // right-associative operator?
- $ops_p = array('+'=>0,'-'=>0,'*'=>1,'/'=>1,'_'=>1,'^'=>2); // operator precedence
-
- $expecting_op = false; // we use this in syntax-checking the expression
- // and determining when a - is a negation
-
- if (preg_match("/[^\w\s+*^\/()\.,-]/", $expr, $matches)) { // make sure the characters are all good
- return $this->trigger("illegal character '{$matches[0]}'");
- }
-
- while(1) { // 1 Infinite Loop ;)
- $op = substr($expr, $index, 1); // get the first character at the current index
- // find out if we're currently at the beginning of a number/variable/function/parenthesis/operand
- $ex = preg_match('/^([a-z][a-z0-9]*\(?|\d+(?:\.\d*)?|\.\d+|\()/', substr($expr, $index), $match);
- //===============
- if ($op == '-' and !$expecting_op) { // is it a negation instead of a minus?
- $stack->push('_'); // put a negation on the stack
- $index++;
- } elseif ($op == '_') { // we have to explicitly deny this, because it's legal on the stack
- return $this->trigger("illegal character '_'"); // but not in the input expression
- //===============
- } elseif ((in_array($op, $ops) or $ex) and $expecting_op) { // are we putting an operator on the stack?
- if ($ex) { // are we expecting an operator but have a number/variable/function/opening parethesis?
- return $this->trigger("expecting operand");
- //$op = '*'; $index--; // it's an implicit multiplication
- }
- // heart of the algorithm:
- while($stack->count > 0 and ($o2 = $stack->last()) and in_array($o2, $ops) and ($ops_r[$op] ? $ops_p[$op] < $ops_p[$o2] : $ops_p[$op] <= $ops_p[$o2])) {
- $output[] = $stack->pop(); // pop stuff off the stack into the output
- }
- // many thanks: http://en.wikipedia.org/wiki/Reverse_Polish_notation#The_algorithm_in_detail
- $stack->push($op); // finally put OUR operator onto the stack
- $index++;
- $expecting_op = false;
- //===============
- } elseif ($op == ')' and $expecting_op) { // ready to close a parenthesis?
- while (($o2 = $stack->pop()) != '(') { // pop off the stack back to the last (
- if (is_null($o2)) return $this->trigger("unexpected ')'");
- else $output[] = $o2;
- }
- if (preg_match("/^([a-z][a-z0-9]*)\($/", $stack->last(2), $matches)) { // did we just close a function?
- $fnn = $matches[1]; // get the function name
- $arg_count = $stack->pop(); // see how many arguments there were (cleverly stored on the stack, thank you)
- $fn = $stack->pop();
- $output[] = array('fn'=>$fn, 'fnn'=>$fnn, 'argcount'=>$arg_count); // send function to output
- if (in_array($fnn, $this->fb)) { // check the argument count
- if($arg_count > 1)
- return $this->trigger("too many arguments ($arg_count given, 1 expected)");
- } elseif (array_key_exists($fnn, $this->fc)) {
- $counts = $this->fc[$fnn];
- if (in_array(-1, $counts) and $arg_count > 0) {}
- elseif (!in_array($arg_count, $counts))
- return $this->trigger("wrong number of arguments ($arg_count given, " . implode('/',$this->fc[$fnn]) . " expected)");
- } elseif (array_key_exists($fnn, $this->f)) {
- if ($arg_count != count($this->f[$fnn]['args']))
- return $this->trigger("wrong number of arguments ($arg_count given, " . count($this->f[$fnn]['args']) . " expected)");
- } else { // did we somehow push a non-function on the stack? this should never happen
- return $this->trigger("internal error");
- }
- }
- $index++;
- //===============
- } elseif ($op == ',' and $expecting_op) { // did we just finish a function argument?
- while (($o2 = $stack->pop()) != '(') {
- if (is_null($o2)) return $this->trigger("unexpected ','"); // oops, never had a (
- else $output[] = $o2; // pop the argument expression stuff and push onto the output
- }
- // make sure there was a function
- if (!preg_match("/^([a-z][a-z0-9]*)\($/", $stack->last(2), $matches))
- return $this->trigger("unexpected ','");
- $stack->push($stack->pop()+1); // increment the argument count
- $stack->push('('); // put the ( back on, we'll need to pop back to it again
- $index++;
- $expecting_op = false;
- //===============
- } elseif ($op == '(' and !$expecting_op) {
- $stack->push('('); // that was easy
- $index++;
- $allow_neg = true;
- //===============
- } elseif ($ex and !$expecting_op) { // do we now have a function/variable/number?
- $expecting_op = true;
- $val = $match[1];
- if (preg_match("/^([a-z][a-z0-9]*)\($/", $val, $matches)) { // may be func, or variable w/ implicit multiplication against parentheses...
- if (in_array($matches[1], $this->fb) or array_key_exists($matches[1], $this->f) or array_key_exists($matches[1], $this->fc)) { // it's a func
- $stack->push($val);
- $stack->push(1);
- $stack->push('(');
- $expecting_op = false;
- } else { // it's a var w/ implicit multiplication
- $val = $matches[1];
- $output[] = $val;
- }
- } else { // it's a plain old var or num
- $output[] = $val;
- }
- $index += strlen($val);
- //===============
- } elseif ($op == ')') {
- //it could be only custom function with no params or general error
- if ($stack->last() != '(' or $stack->last(2) != 1) return $this->trigger("unexpected ')'");
- if (preg_match("/^([a-z][a-z0-9]*)\($/", $stack->last(3), $matches)) { // did we just close a function?
- $stack->pop();// (
- $stack->pop();// 1
- $fn = $stack->pop();
- $fnn = $matches[1]; // get the function name
- $counts = $this->fc[$fnn];
- if (!in_array(0, $counts))
- return $this->trigger("wrong number of arguments ($arg_count given, " . implode('/',$this->fc[$fnn]) . " expected)");
- $output[] = array('fn'=>$fn, 'fnn'=>$fnn, 'argcount'=>0); // send function to output
- $index++;
- } else {
- return $this->trigger("unexpected ')'");
- }
- //===============
- } elseif (in_array($op, $ops) and !$expecting_op) { // miscellaneous error checking
- return $this->trigger("unexpected operator '$op'");
- } else { // I don't even want to know what you did to get here
- return $this->trigger("an unexpected error occured");
- }
- if ($index == strlen($expr)) {
- if (in_array($op, $ops)) { // did we end with an operator? bad.
- return $this->trigger("operator '$op' lacks operand");
- } else {
- break;
- }
- }
- while (substr($expr, $index, 1) == ' ') { // step the index past whitespace (pretty much turns whitespace
- $index++; // into implicit multiplication if no operator is there)
- }
-
- }
- while (!is_null($op = $stack->pop())) { // pop everything off the stack and push onto output
- if ($op == '(') return $this->trigger("expecting ')'"); // if there are (s on the stack, ()s were unbalanced
- $output[] = $op;
- }
- return $output;
- }
-
- // evaluate postfix notation
- function pfx($tokens, $vars = array()) {
-
- if ($tokens == false) return false;
-
- $stack = new EvalMathStack;
-
- foreach ($tokens as $token) { // nice and easy
-
- // if the token is a function, pop arguments off the stack, hand them to the function, and push the result back on
- if (is_array($token)) { // it's a function!
- $fnn = $token['fnn'];
- $count = $token['argcount'];
- if (in_array($fnn, $this->fb)) { // built-in function:
- if (is_null($op1 = $stack->pop())) return $this->trigger("internal error");
- $fnn = preg_replace("/^arc/", "a", $fnn); // for the 'arc' trig synonyms
- if ($fnn == 'ln') $fnn = 'log';
- eval('$stack->push(' . $fnn . '($op1));'); // perfectly safe eval()
- } elseif (array_key_exists($fnn, $this->fc)) { // calc emulation function
- // get args
- $args = array();
- for ($i = $count-1; $i >= 0; $i--) {
- if (is_null($args[] = $stack->pop())) return $this->trigger("internal error");
- }
- $res = call_user_func(array('EvalMathCalcEmul', $fnn), $args);
- if ($res == FALSE) {
- return $this->trigger("internal error");
- }
- $stack->push($res);
- } elseif (array_key_exists($fnn, $this->f)) { // user function
- // get args
- $args = array();
- for ($i = count($this->f[$fnn]['args'])-1; $i >= 0; $i--) {
- if (is_null($args[$this->f[$fnn]['args'][$i]] = $stack->pop())) return $this->trigger("internal error");
- }
- $stack->push($this->pfx($this->f[$fnn]['func'], $args)); // yay... recursion!!!!
- }
- // if the token is a binary operator, pop two values off the stack, do the operation, and push the result back on
- } elseif (in_array($token, array('+', '-', '*', '/', '^'), true)) {
- if (is_null($op2 = $stack->pop())) return $this->trigger("internal error");
- if (is_null($op1 = $stack->pop())) return $this->trigger("internal error");
- switch ($token) {
- case '+':
- $stack->push($op1+$op2); break;
- case '-':
- $stack->push($op1-$op2); break;
- case '*':
- $stack->push($op1*$op2); break;
- case '/':
- if ($op2 == 0) return $this->trigger("division by zero");
- $stack->push($op1/$op2); break;
- case '^':
- $stack->push(pow($op1, $op2)); break;
- }
- // if the token is a unary operator, pop one value off the stack, do the operation, and push it back on
- } elseif ($token == "_") {
- $stack->push(-1*$stack->pop());
- // if the token is a number or variable, push it on the stack
- } else {
- if (is_numeric($token)) {
- $stack->push($token);
- } elseif (array_key_exists($token, $this->v)) {
- $stack->push($this->v[$token]);
- } elseif (array_key_exists($token, $vars)) {
- $stack->push($vars[$token]);
- } else {
- return $this->trigger("undefined variable '$token'");
- }
- }
- }
- // when we're out of tokens, the stack should have a single element, the final result
- if ($stack->count != 1) return $this->trigger("internal error");
- return $stack->pop();
- }
-
- // trigger an error, but nicely, if need be
- function trigger($msg) {
- $this->last_error = $msg;
- if (!$this->suppress_errors) trigger_error($msg, E_USER_WARNING);
- return false;
- }
-}
-
-// for internal use
-class EvalMathStack {
-
- var $stack = array();
- var $count = 0;
-
- function push($val) {
- $this->stack[$this->count] = $val;
- $this->count++;
- }
-
- function pop() {
- if ($this->count > 0) {
- $this->count--;
- return $this->stack[$this->count];
- }
- return null;
- }
-
- function last($n=1) {
- return $this->stack[$this->count-$n];
- }
-}
-
-// spreadsheed functions emulation
-// watch out for reversed args!!
-class EvalMathCalcEmul {
-
- function average($args) {
- return (EvalMathCalcEmul::sum($args)/count($args));
- }
-
- function max($args) {
- $res = array_pop($args);
- foreach($args as $a) {
- if ($res < $a) {
- $res = $a;
- }
- }
- return $res;
- }
-
- function min($args) {
- $res = array_pop($args);
- foreach($args as $a) {
- if ($res > $a) {
- $res = $a;
- }
- }
- return $res;
- }
-
- function mod($args) {
- return $args[1] % $args[0];
- }
-
- function pi($args) {
- return pi();
- }
-
- function power($args) {
- return $args[1]^$args[0];
- }
-
- function round($args) {
- if (count($args)==1) {
- return round($args[0]);
- } else {
- return round($args[1], $args[0]);
- }
- }
-
- function sum($args) {
- $res = 0;
- foreach($args as $a) {
- $res += $a;
- }
- return $res;
- }
-}
+<?php
+
+/*
+================================================================================
+
+EvalMath - PHP Class to safely evaluate math expressions
+Copyright (C) 2005 Miles Kaufmann <http://www.twmagic.com/>
+
+================================================================================
+
+NAME
+ EvalMath - safely evaluate math expressions
+
+SYNOPSIS
+ <?
+ include('evalmath.class.php');
+ $m = new EvalMath;
+ // basic evaluation:
+ $result = $m->evaluate('2+2');
+ // supports: order of operation; parentheses; negation; built-in functions
+ $result = $m->evaluate('-8(5/2)^2*(1-sqrt(4))-8');
+ // create your own variables
+ $m->evaluate('a = e^(ln(pi))');
+ // or functions
+ $m->evaluate('f(x,y) = x^2 + y^2 - 2x*y + 1');
+ // and then use them
+ $result = $m->evaluate('3*f(42,a)');
+ ?>
+
+DESCRIPTION
+ Use the EvalMath class when you want to evaluate mathematical expressions
+ from untrusted sources. You can define your own variables and functions,
+ which are stored in the object. Try it, it's fun!
+
+METHODS
+ $m->evalute($expr)
+ Evaluates the expression and returns the result. If an error occurs,
+ prints a warning and returns false. If $expr is a function assignment,
+ returns true on success.
+
+ $m->e($expr)
+ A synonym for $m->evaluate().
+
+ $m->vars()
+ Returns an associative array of all user-defined variables and values.
+
+ $m->funcs()
+ Returns an array of all user-defined functions.
+
+PARAMETERS
+ $m->suppress_errors
+ Set to true to turn off warnings when evaluating expressions
+
+ $m->last_error
+ If the last evaluation failed, contains a string describing the error.
+ (Useful when suppress_errors is on).
+
+AUTHOR INFORMATION
+ Copyright 2005, Miles Kaufmann.
+
+LICENSE
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are
+ met:
+
+ 1 Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+ 2. Redistributions in binary form must reproduce the above copyright
+ notice, this list of conditions and the following disclaimer in the
+ documentation and/or other materials provided with the distribution.
+ 3. The name of the author may not be used to endorse or promote
+ products derived from this software without specific prior written
+ permission.
+
+ THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+ INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ POSSIBILITY OF SUCH DAMAGE.
+
+*/
+
+/**
+ * This class was heavily modified in order to get usefull spreadsheet emulation ;-)
+ * skodak
+ *
+ */
+
+class EvalMath {
+
+ var $suppress_errors = false;
+ var $last_error = null;
+
+ var $v = array(); // variables (and constants)
+ var $f = array(); // user-defined functions
+ var $vb = array(); // constants
+ var $fb = array( // built-in functions
+ 'sin','sinh','arcsin','asin','arcsinh','asinh',
+ 'cos','cosh','arccos','acos','arccosh','acosh',
+ 'tan','tanh','arctan','atan','arctanh','atanh',
+ 'sqrt','abs','ln','log','exp');
+
+ var $fc = array( // calc functions emulation
+ 'average'=>array(-1), 'max'=>array(-1), 'min'=>array(-1),
+ 'mod'=>array(2), 'pi'=>array(0), 'power'=>array(2),
+ 'round'=>array(1, 2), 'sum'=>array(-1));
+
+ function EvalMath() {
+ }
+
+ function e($expr) {
+ return $this->evaluate($expr);
+ }
+
+ function evaluate($expr) {
+ $this->last_error = null;
+ $expr = trim($expr);
+ if (substr($expr, -1, 1) == ';') $expr = substr($expr, 0, strlen($expr)-1); // strip semicolons at the end
+ //===============
+ // is it a variable assignment?
+ if (preg_match('/^\s*([a-z][a-z0-9]*)\s*=\s*(.+)$/', $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][a-z0-9]*)\s*\(\s*([a-z][a-z0-9]*(?:\s*,\s*[a-z][a-z0-9]*)*)\s*\)\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][a-z0-9]*$/', $token) and !in_array($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
+ }
+ }
+
+ function vars() {
+ return $this->v;
+ }
+
+ function funcs() {
+ $output = array();
+ foreach ($this->f as $fnn=>$dat)
+ $output[] = $fnn . '(' . implode(',', $dat['args']) . ')';
+ return $output;
+ }
+
+ //===================== HERE BE INTERNAL METHODS ====================\\
+
+ // Convert infix to postfix notation
+ function nfx($expr) {
+
+ $index = 0;
+ $stack = new EvalMathStack;
+ $output = array(); // postfix form of expression, to be passed to pfx()
+ $expr = trim(strtolower($expr));
+
+ $ops = array('+', '-', '*', '/', '^', '_');
+ $ops_r = array('+'=>0,'-'=>0,'*'=>0,'/'=>0,'^'=>1); // right-associative operator?
+ $ops_p = array('+'=>0,'-'=>0,'*'=>1,'/'=>1,'_'=>1,'^'=>2); // operator precedence
+
+ $expecting_op = false; // we use this in syntax-checking the expression
+ // and determining when a - is a negation
+
+ if (preg_match("/[^\w\s+*^\/()\.,-]/", $expr, $matches)) { // make sure the characters are all good
+ return $this->trigger("illegal character '{$matches[0]}'");
+ }
+
+ while(1) { // 1 Infinite Loop ;)
+ $op = substr($expr, $index, 1); // get the first character at the current index
+ // find out if we're currently at the beginning of a number/variable/function/parenthesis/operand
+ $ex = preg_match('/^([a-z][a-z0-9]*\(?|\d+(?:\.\d*)?|\.\d+|\()/', substr($expr, $index), $match);
+ //===============
+ if ($op == '-' and !$expecting_op) { // is it a negation instead of a minus?
+ $stack->push('_'); // put a negation on the stack
+ $index++;
+ } elseif ($op == '_') { // we have to explicitly deny this, because it's legal on the stack
+ return $this->trigger("illegal character '_'"); // but not in the input expression
+ //===============
+ } elseif ((in_array($op, $ops) or $ex) and $expecting_op) { // are we putting an operator on the stack?
+ if ($ex) { // are we expecting an operator but have a number/variable/function/opening parethesis?
+ return $this->trigger("expecting operand");
+ //$op = '*'; $index--; // it's an implicit multiplication
+ }
+ // heart of the algorithm:
+ while($stack->count > 0 and ($o2 = $stack->last()) and in_array($o2, $ops) and ($ops_r[$op] ? $ops_p[$op] < $ops_p[$o2] : $ops_p[$op] <= $ops_p[$o2])) {
+ $output[] = $stack->pop(); // pop stuff off the stack into the output
+ }
+ // many thanks: http://en.wikipedia.org/wiki/Reverse_Polish_notation#The_algorithm_in_detail
+ $stack->push($op); // finally put OUR operator onto the stack
+ $index++;
+ $expecting_op = false;
+ //===============
+ } elseif ($op == ')' and $expecting_op) { // ready to close a parenthesis?
+ while (($o2 = $stack->pop()) != '(') { // pop off the stack back to the last (
+ if (is_null($o2)) return $this->trigger("unexpected ')'");
+ else $output[] = $o2;
+ }
+ if (preg_match("/^([a-z][a-z0-9]*)\($/", $stack->last(2), $matches)) { // did we just close a function?
+ $fnn = $matches[1]; // get the function name
+ $arg_count = $stack->pop(); // see how many arguments there were (cleverly stored on the stack, thank you)
+ $fn = $stack->pop();
+ $output[] = array('fn'=>$fn, 'fnn'=>$fnn, 'argcount'=>$arg_count); // send function to output
+ if (in_array($fnn, $this->fb)) { // check the argument count
+ if($arg_count > 1)
+ return $this->trigger("too many arguments ($arg_count given, 1 expected)");
+ } elseif (array_key_exists($fnn, $this->fc)) {
+ $counts = $this->fc[$fnn];
+ if (in_array(-1, $counts) and $arg_count > 0) {}
+ elseif (!in_array($arg_count, $counts))
+ return $this->trigger("wrong number of arguments ($arg_count given, " . implode('/',$this->fc[$fnn]) . " expected)");
+ } elseif (array_key_exists($fnn, $this->f)) {
+ if ($arg_count != count($this->f[$fnn]['args']))
+ return $this->trigger("wrong number of arguments ($arg_count given, " . count($this->f[$fnn]['args']) . " expected)");
+ } else { // did we somehow push a non-function on the stack? this should never happen
+ return $this->trigger("internal error");
+ }
+ }
+ $index++;
+ //===============
+ } elseif ($op == ',' and $expecting_op) { // did we just finish a function argument?
+ while (($o2 = $stack->pop()) != '(') {
+ if (is_null($o2)) return $this->trigger("unexpected ','"); // oops, never had a (
+ else $output[] = $o2; // pop the argument expression stuff and push onto the output
+ }
+ // make sure there was a function
+ if (!preg_match("/^([a-z][a-z0-9]*)\($/", $stack->last(2), $matches))
+ return $this->trigger("unexpected ','");
+ $stack->push($stack->pop()+1); // increment the argument count
+ $stack->push('('); // put the ( back on, we'll need to pop back to it again
+ $index++;
+ $expecting_op = false;
+ //===============
+ } elseif ($op == '(' and !$expecting_op) {
+ $stack->push('('); // that was easy
+ $index++;
+ $allow_neg = true;
+ //===============
+ } elseif ($ex and !$expecting_op) { // do we now have a function/variable/number?
+ $expecting_op = true;
+ $val = $match[1];
+ if (preg_match("/^([a-z][a-z0-9]*)\($/", $val, $matches)) { // may be func, or variable w/ implicit multiplication against parentheses...
+ if (in_array($matches[1], $this->fb) or array_key_exists($matches[1], $this->f) or array_key_exists($matches[1], $this->fc)) { // it's a func
+ $stack->push($val);
+ $stack->push(1);
+ $stack->push('(');
+ $expecting_op = false;
+ } else { // it's a var w/ implicit multiplication
+ $val = $matches[1];
+ $output[] = $val;
+ }
+ } else { // it's a plain old var or num
+ $output[] = $val;
+ }
+ $index += strlen($val);
+ //===============
+ } elseif ($op == ')') {
+ //it could be only custom function with no params or general error
+ if ($stack->last() != '(' or $stack->last(2) != 1) return $this->trigger("unexpected ')'");
+ if (preg_match("/^([a-z][a-z0-9]*)\($/", $stack->last(3), $matches)) { // did we just close a function?
+ $stack->pop();// (
+ $stack->pop();// 1
+ $fn = $stack->pop();
+ $fnn = $matches[1]; // get the function name
+ $counts = $this->fc[$fnn];
+ if (!in_array(0, $counts))
+ return $this->trigger("wrong number of arguments ($arg_count given, " . implode('/',$this->fc[$fnn]) . " expected)");
+ $output[] = array('fn'=>$fn, 'fnn'=>$fnn, 'argcount'=>0); // send function to output
+ $index++;
+ } else {
+ return $this->trigger("unexpected ')'");
+ }
+ //===============
+ } elseif (in_array($op, $ops) and !$expecting_op) { // miscellaneous error checking
+ return $this->trigger("unexpected operator '$op'");
+ } else { // I don't even want to know what you did to get here
+ return $this->trigger("an unexpected error occured");
+ }
+ if ($index == strlen($expr)) {
+ if (in_array($op, $ops)) { // did we end with an operator? bad.
+ return $this->trigger("operator '$op' lacks operand");
+ } else {
+ break;
+ }
+ }
+ while (substr($expr, $index, 1) == ' ') { // step the index past whitespace (pretty much turns whitespace
+ $index++; // into implicit multiplication if no operator is there)
+ }
+
+ }
+ while (!is_null($op = $stack->pop())) { // pop everything off the stack and push onto output
+ if ($op == '(') return $this->trigger("expecting ')'"); // if there are (s on the stack, ()s were unbalanced
+ $output[] = $op;
+ }
+ return $output;
+ }
+
+ // evaluate postfix notation
+ function pfx($tokens, $vars = array()) {
+
+ if ($tokens == false) return false;
+
+ $stack = new EvalMathStack;
+
+ foreach ($tokens as $token) { // nice and easy
+
+ // if the token is a function, pop arguments off the stack, hand them to the function, and push the result back on
+ if (is_array($token)) { // it's a function!
+ $fnn = $token['fnn'];
+ $count = $token['argcount'];
+ if (in_array($fnn, $this->fb)) { // built-in function:
+ if (is_null($op1 = $stack->pop())) return $this->trigger("internal error");
+ $fnn = preg_replace("/^arc/", "a", $fnn); // for the 'arc' trig synonyms
+ if ($fnn == 'ln') $fnn = 'log';
+ eval('$stack->push(' . $fnn . '($op1));'); // perfectly safe eval()
+ } elseif (array_key_exists($fnn, $this->fc)) { // calc emulation function
+ // get args
+ $args = array();
+ for ($i = $count-1; $i >= 0; $i--) {
+ if (is_null($args[] = $stack->pop())) return $this->trigger("internal error");
+ }
+ $res = call_user_func(array('EvalMathCalcEmul', $fnn), $args);
+ if ($res === FALSE) {
+ return $this->trigger("internal error");
+ }
+ $stack->push($res);
+ } elseif (array_key_exists($fnn, $this->f)) { // user function
+ // get args
+ $args = array();
+ for ($i = count($this->f[$fnn]['args'])-1; $i >= 0; $i--) {
+ if (is_null($args[$this->f[$fnn]['args'][$i]] = $stack->pop())) return $this->trigger("internal error");
+ }
+ $stack->push($this->pfx($this->f[$fnn]['func'], $args)); // yay... recursion!!!!
+ }
+ // if the token is a binary operator, pop two values off the stack, do the operation, and push the result back on
+ } elseif (in_array($token, array('+', '-', '*', '/', '^'), true)) {
+ if (is_null($op2 = $stack->pop())) return $this->trigger("internal error");
+ if (is_null($op1 = $stack->pop())) return $this->trigger("internal error");
+ switch ($token) {
+ case '+':
+ $stack->push($op1+$op2); break;
+ case '-':
+ $stack->push($op1-$op2); break;
+ case '*':
+ $stack->push($op1*$op2); break;
+ case '/':
+ if ($op2 == 0) return $this->trigger("division by zero");
+ $stack->push($op1/$op2); break;
+ case '^':
+ $stack->push(pow($op1, $op2)); break;
+ }
+ // if the token is a unary operator, pop one value off the stack, do the operation, and push it back on
+ } elseif ($token == "_") {
+ $stack->push(-1*$stack->pop());
+ // if the token is a number or variable, push it on the stack
+ } else {
+ if (is_numeric($token)) {
+ $stack->push($token);
+ } elseif (array_key_exists($token, $this->v)) {
+ $stack->push($this->v[$token]);
+ } elseif (array_key_exists($token, $vars)) {
+ $stack->push($vars[$token]);
+ } else {
+ return $this->trigger("undefined variable '$token'");
+ }
+ }
+ }
+ // when we're out of tokens, the stack should have a single element, the final result
+ if ($stack->count != 1) return $this->trigger("internal error");
+ return $stack->pop();
+ }
+
+ // trigger an error, but nicely, if need be
+ function trigger($msg) {
+ $this->last_error = $msg;
+ if (!$this->suppress_errors) trigger_error($msg, E_USER_WARNING);
+ return false;
+ }
+}
+
+// for internal use
+class EvalMathStack {
+
+ var $stack = array();
+ var $count = 0;
+
+ function push($val) {
+ $this->stack[$this->count] = $val;
+ $this->count++;
+ }
+
+ function pop() {
+ if ($this->count > 0) {
+ $this->count--;
+ return $this->stack[$this->count];
+ }
+ return null;
+ }
+
+ function last($n=1) {
+ return $this->stack[$this->count-$n];
+ }
+}
+
+// spreadsheed functions emulation
+// watch out for reversed args!!
+class EvalMathCalcEmul {
+
+ function average($args) {
+ return (EvalMathCalcEmul::sum($args)/count($args));
+ }
+
+ function max($args) {
+ $res = array_pop($args);
+ foreach($args as $a) {
+ if ($res < $a) {
+ $res = $a;
+ }
+ }
+ return $res;
+ }
+
+ function min($args) {
+ $res = array_pop($args);
+ foreach($args as $a) {
+ if ($res > $a) {
+ $res = $a;
+ }
+ }
+ return $res;
+ }
+
+ function mod($args) {
+ return $args[1] % $args[0];
+ }
+
+ function pi($args) {
+ return pi();
+ }
+
+ function power($args) {
+ return $args[1]^$args[0];
+ }
+
+ function round($args) {
+ if (count($args)==1) {
+ return round($args[0]);
+ } else {
+ return round($args[1], $args[0]);
+ }
+ }
+
+ function sum($args) {
+ $res = 0;
+ foreach($args as $a) {
+ $res += $a;
+ }
+ return $res;
+ }
+}
diff --git a/lib/evalmath/readme_moodle.txt b/lib/evalmath/readme_moodle.txt
index 6f5a33fefa2..e1417eb251d 100644
--- a/lib/evalmath/readme_moodle.txt
+++ b/lib/evalmath/readme_moodle.txt
@@ -1,13 +1,13 @@
-Description of MathEval library import into Moodle
+Description of EvalMath library import into Moodle
Our changes:
* implicit multiplication not allowed
* new custom calc emulation functions
* removed e and pi constants - not use din calc
* removed sample files
+* Fix a == FALSE that should have been === FALSE.
-To see all changes diff against version 1.1
+To see all changes diff against version 1.1, available from:
+http://www.phpclasses.org/browse/package/2695.html
-skodak
-
-$Id$
+skodak, Tim Hunt
\ No newline at end of file