Logicandcompare (#50)

* TokenFactory: allowing multicharacter tokens

* Added logical and compare operators: <, <=, >, >=, ==, !=, ||, &&

* Fixed operator priorities

* Error messages fixes

* Fixed operators priority

The priorities are assigned by following the php language standard
(https://www.php.net/manual/en/language.operators.precedence.php)
I've assigned precedence in steps of 10 units by following the linked page:
230 clone new
220 **
210 ++ -- ~ (int) (float) (string) (array) (object) (bool) @
200 instanceof
190 !
180 * / %
170 + - .
160 << >>
150 < <= > >=
140 == != === !== <> <=>
130 &
120 ^
110 |
100 &&
 90 ||
 80 ??
 70 ? :
 60 = += -= *= **= /= .= %= &= |= ^= <<= >>=
 50 yield from
 40 yield
 30 and
 20 xor
 10 or

* Added if() function

* Cache key fix

There are cases where the cache key creation raised an error, for example
while evaluating the expression "if(cos(2), cos(2), 0)", because the
if() function was passing a float to the MathExecutor:execute() method.

1 files changed, 24 insertions, 3 deletions

diff --git a/src/NXP/MathExecutor.php b/src/NXP/MathExecutor.php
index 6325d35..2a5f9fb 100644
--- a/src/NXP/MathExecutor.php
+++ b/src/NXP/MathExecutor.php
@@ -223,13 +223,14 @@ class MathExecutor
      */
     public function execute($expression)
     {
-        if (!array_key_exists($expression, $this->cache)) {
+        $cachekey = (string)$expression;
+        if (!array_key_exists($cachekey, $this->cache)) {
             $lexer = new Lexer($this->tokenFactory);
             $tokensStream = $lexer->stringToTokensStream($expression);
             $tokens = $lexer->buildReversePolishNotation($tokensStream);
-            $this->cache[$expression] = $tokens;
+            $this->cache[$cachekey] = $tokens;
         } else {
-            $tokens = $this->cache[$expression];
+            $tokens = $this->cache[$cachekey];
         }
         $calculator = new Calculator();
         $result = $calculator->calculate($tokens, $this->variables);
@@ -263,6 +264,14 @@ class MathExecutor
             'NXP\Classes\Token\TokenMultiply',
             'NXP\Classes\Token\TokenDivision',
             'NXP\Classes\Token\TokenDegree',
+            'NXP\Classes\Token\TokenAnd',
+            'NXP\Classes\Token\TokenOr',
+            'NXP\Classes\Token\TokenEqual',
+            'NXP\Classes\Token\TokenUnequal',
+            'NXP\Classes\Token\TokenGreaterThanOrEqual',
+            'NXP\Classes\Token\TokenGreaterThan',
+            'NXP\Classes\Token\TokenLessThanOrEqual',
+            'NXP\Classes\Token\TokenLessThan',
         ];
     }
 
@@ -296,6 +305,18 @@ class MathExecutor
             'avg' => function ($arg1, $arg2) {
                 return ($arg1 + $arg2) / 2;
             },
+            'if' => function ($expr, $trueval, $falseval) {
+                if ($expr === true || $expr === false) {
+                    $exres = $expr;
+                } else {
+                    $exres = $this->execute($expr);
+                }
+                if ($exres) {
+                    return $this->execute($trueval);
+                } else {
+                    return $this->execute($falseval);
+                }
+            }
         ];
     }