Add support for exponential numbers

CHANGELOG

@@ -1,6 +1,6 @@
 * 1.42.4 (2019-XX-XX)
 
- * n/a
+ * added supported for exponential numbers
 
 * 1.42.3 (2019-08-24)
 

src/Lexer.php

@@ -47,7 +47,7 @@ class Lexer implements \Twig_LexerInterface
     const STATE_INTERPOLATION = 4;
 
     const REGEX_NAME = '/[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*/A';
-    const REGEX_NUMBER = '/[0-9]+(?:\.[0-9]+)?/A';
+    const REGEX_NUMBER = '/[0-9]+(?:\.[0-9]+)?([Ee][\+\-][0-9]+)?/A';
     const REGEX_STRING = '/"([^#"\\\\]*(?:\\\\.[^#"\\\\]*)*)"|\'([^\'\\\\]*(?:\\\\.[^\'\\\\]*)*)\'/As';
     const REGEX_DQ_STRING_DELIM = '/"/A';
     const REGEX_DQ_STRING_PART = '/[^#"\\\\]*(?:(?:\\\\.|#(?!\{))[^#"\\\\]*)*/As';

tests/Fixtures/expressions/exponential_numbers.test

@@ -0,0 +1,8 @@
+--TEST--
+Twig manages exponentiel numbers correctly
+--TEMPLATE--
+{{ 1.99E+3 }}
+--DATA--
+return []
+--EXPECT--
+1990