Negative expression start (#60)

* Update documentation for PHPFUI/InstaDoc

* Support for negative numbers starting paren enclosed expressions

2 files changed, 10 insertions, 3 deletions

diff --git a/src/NXP/Classes/Lexer.php b/src/NXP/Classes/Lexer.php
index a7fe697..9964de9 100644
--- a/src/NXP/Classes/Lexer.php
+++ b/src/NXP/Classes/Lexer.php
@@ -76,10 +76,10 @@ class Lexer
                 $output[] = $token;
             } elseif ($token instanceof TokenNumber) {
                 // if the number starts with a minus sign, it could be a negative number, or it could be an operator grabbed by the greedy regex
-                // if previous token is an operator, then it negative, otherwise remove the minus sign and put a negative operator on the stack
+                // if previous token is an operator or open bracket, then it negative, otherwise remove the minus sign and put a negative operator on the stack
                 if ($lastToken !== null) {
                     $value = $token->getValue();
-                    if (($value < 0 || $this->isNegativeZero($value)) && ! ($lastToken instanceof AbstractOperator)) {
+                    if (($value < 0 || $this->isNegativeZero($value)) && ! ($lastToken instanceof AbstractOperator || $lastToken instanceof TokenLeftBracket)) {
                         $token = new TokenNumber(abs($value));
                         $output[] = $token;
                         $output[] = new TokenMinus('-');
diff --git a/tests/MathTest.php b/tests/MathTest.php
index cc4cd1a..7cbc7de 100644
--- a/tests/MathTest.php
+++ b/tests/MathTest.php
@@ -114,6 +114,7 @@ class MathTest extends \PHPUnit\Framework\TestCase
 
             ['(5 + 3) * -1'],
 
+            ['-2- 2*2'],
             ['2- 2*2'],
             ['2-(2*2)'],
             ['(2- 2)*2'],
@@ -155,6 +156,7 @@ class MathTest extends \PHPUnit\Framework\TestCase
             ['-1*-2'],
 
             ['(1+2+3+4-5)*7/100'],
+            ['(-1+2+3+4- 5)*7/100'],
             ['(1+2+3+4- 5)*7/100'],
             ['( 1 + 2 + 3 + 4 - 5 ) * 7 / 100'],
 
@@ -176,6 +178,7 @@ class MathTest extends \PHPUnit\Framework\TestCase
             ['3 <= 5'],
             ['5 <= 5'],
             ['10 < 9 || 4 > (2+1)'],
+            ['10 < 9 || 4 > (-2+1)'],
             ['10 < 9 || 4 > (2+1) && 5 == 5 || 4 != 6 || 3 >= 4 || 3 <= 7'],
 
             ['1 + 5 == 3 + 1'],
@@ -193,7 +196,11 @@ class MathTest extends \PHPUnit\Framework\TestCase
 
             ['(-4)'],
             ['(-4 + 5)'],
-
+            ['(3 * 1)'],
+            ['(-3 * -1)'],
+            ['1 + (-3 * -1)'],
+            ['1 + ( -3 * 1)'],
+            ['1 + (3 * -1)'],
             ['1 - 0'],
             ['1-0'],
         ];