enh(php): Tidy up regex rules

- Use `\<` and `\>` to match word boundaries, instead of `[^a-z0-9_-]{1}`
- Fix the OR operator `||` being highlighted twice.
- Fix cannot include escapes in quoted strings.
- Fix redundant highlights to HEREDOC.
- Make inline comments regex more compact.
- Variables: Remove parts that does not seem relevant

Author: davidhcefx

php.nanorc

@@ -3,19 +3,22 @@ syntax "PHP" "\.php[2345s~]?$|\.module$"
 header "^#!.*php"
 magic "PHP script"
 comment "//"
+
+# Default
 color white start="<\?(php|=)?" end="\?>"
 # Constructs
 color brightblue "(class|extends|goto) ([a-zA-Z0-9_]*)"
-color brightblue "[^a-z0-9_-]{1}(var|class|function|echo|case|break|default|exit|switch|if|else|elseif|endif|foreach|endforeach|@|while|public|private|protected|return|const|static|extends|as|array|require|include|require_once|include_once|define|do|continue|declare|goto|print|in|namespace|use)[^a-z0-9_-]{1}"
+color brightblue "\<(var|class|function|echo|case|break|default|exit|switch|if|else|elseif|endif|foreach|endforeach|@|while|public|private|protected|return|const|static|extends|as|array|require|include|require_once|include_once|define|do|continue|declare|goto|print|in|namespace|use)\>"
 color brightblue "[a-zA-Z0-9_]+:"
 # Variables
-color green "\$[a-zA-Z_0-9$]*|[=!<>]"
-color green "\->[a-zA-Z_0-9$]*|[=!<>]"
+#color green "\$[a-zA-Z_0-9]*|[=!<>]"
+#color green "\->[a-zA-Z_0-9$]*|[=!<>]"
+color green "\$[a-zA-Z_0-9]*"
+color green "\->[a-zA-Z_0-9]*"
 # Functions
 color brightblue "([a-zA-Z0-9_-]*)\("
 # Special values
-color brightmagenta "[^a-z0-9_-]{1}(true|false|null|TRUE|FALSE|NULL)$"
-color brightmagenta "[^a-z0-9_-]{1}(true|false|null|TRUE|FALSE|NULL)[^A-Za-z0-9_-]{1}"
+color brightmagenta "\<(true|false|null|TRUE|FALSE|NULL)\>"
 # Special Characters
 color yellow "[.,{}();]"
 color cyan "\["
@@ -30,26 +33,25 @@ color magenta ";"
 color yellow "(<|>)"
 # Assignment operator
 color brightblue "="
-# Bitwise Operations
+# Bitwise operators
 color magenta "(&|\||\^)"
 color magenta "(<<|>>)"
 # Comparison operators
 color yellow "(==|===|!=|<>|!==|<=|>=|<=>)"
 # Logical Operators
-color yellow "( and | or | xor |!|&&|\|\|)"
-# And/Or/SRO/etc
-color cyan "(\;\;|\|\||::|=>|->)"
+color yellow "\<(and|or|xor)\>" "(!|&&|\|\|)"
+# SRO and other operators
+color cyan "(\;\;|::|=>|->)"
 # Double quoted STRINGS!
-color red "(\"[^\"]*\")"
+color red "\"([^"\]|\\.)*\""
+# Single quoted string
+color red "'([^'\]|\\.)*'"
 # Heredoc (typically ends with a semicolon).
 color red start="<<<['\"]?[A-Z][A-Z0-9_]*['\"]?" end="^[A-Z][A-Z0-9_]*;"
 # Inline Variables
 color white "\{\$[^}]*\}"
-# Single quoted string
-color red "('[^']*')"
 # Online Comments
-color brightyellow "^(#.*|//.*)$"
-color brightyellow "[	| ](#.*|//.*)$"
+color brightyellow "(^|[[:blank:]])(#.*|//.*)$"
 # PHP Tags
 color red "(<\?(php)?|\?>)"
 # General HTML
@@ -58,5 +60,3 @@ color red start="\?>" end="<\?(php|=)?"
 color ,green "[[:space:]]+$"
 # multi-line comments
 color brightyellow start="/\*" end="\*/"
-# Nowdoc
-color red start="<<<'[A-Z][A-Z0-9_]*'" end="^[A-Z][A-Z0-9_]*;"