Improve new syntax files and fix a region glitch

runtime/syntax/crystal.yaml

@@ -1,25 +1,60 @@
 filetype: crystal
 
-detect: 
+detect:
     filename: "\\.cr$|Gemfile|config.ru|Rakefile|Capfile|Vagrantfile"
-    header: "^#!.*/(env +)?crystal( |$)"
 
 rules:
+    # Asciibetical list of reserved words
     - statement: "\\b(BEGIN|END|abstract|alias|and|begin|break|case|class|def|defined\\?|do|else|elsif|end|ensure|enum|false|for|fun|if|in|include|lib|loop|macro|module|next|nil|not|of|or|pointerof|private|protected|raise|redo|require|rescue|retry|return|self|sizeof|spawn|struct|super|then|true|type|undef|union|uninitialized|unless|until|when|while|yield)\\b"
+      # Constants
     - constant: "(\\$|@|@@)?\\b[A-Z]+[0-9A-Z_a-z]*"
     - constant.number: "\\b[0-9]+\\b"
-    - constant: "([ 	]|^):[0-9A-Z_]+\\b"
+      # Crystal "symbols"
+    - constant:  "([ 	]|^):[0-9A-Z_]+\\b"
+      # Some unique things we want to stand out
     - constant: "\\b(__FILE__|__LINE__)\\b"
+      # Regular expressions
     - constant: "/([^/]|(\\\\/))*/[iomx]*|%r\\{([^}]|(\\\\}))*\\}[iomx]*"
+
+      # Shell command expansion is in `backticks` or like %x{this}.  These are
+      # "double-quotish" (to use a perlism).
     - constant.string: "`[^`]*`|%x\\{[^}]*\\}"
-    - constant.string: "\"([^\"]|(\\\\\"))*\"|%[QW]?\\{[^}]*\\}|%[QW]?\\([^)]*\\)|%[QW]?<[^>]*>|%[QW]?\\[[^]]*\\]|%[QW]?\\$[^$]*\\$|%[QW]?\\^[^^]*\\^|%[QW]?![^!]*!"
-    - special: "#\\{[^}]*\\}"
-    - constant.string.char: "'([^']|(\\\\'))*'|%[qw]\\{[^}]*\\}|%[qw]\\([^)]*\\)|%[qw]<[^>]*>|%[qw]\\[[^]]*\\]|%[qw]\\$[^$]*\\$|%[qw]\\^[^^]*\\^|%[qw]![^!]*!"
-    - comment: "#[^{].*$|#$"
-    - comment.bright: "##[^{].*$|##$"
+
+    - constant.string:
+        start: "`"
+        end: "`"
+        rules: []
+
+    - constant.string:
+        start: "%x\\{"
+        end: "\\}"
+        rules: []
+
+    - constant.string:
+        start: "\""
+        end: "\""
+        rules:
+            - constant.specialchar: "\\\\."
+            - special: "#\\{[^}]*\\}"
+
+    - constant.string:
+        start: "'"
+        end: "'"
+        rules: []
+
+    - comment:
+        start: "#"
+        end: "$"
+        rules:
+            - todo: "(TODO|XXX|FIXME):?"
+
+    - comment.bright:
+        start: "##"
+        end: "$"
+        rules:
+            - todo: "(TODO|XXX|FIXME):?"
+
     - constant:
         start: "<<-?'?EOT'?"
         end: "^EOT"
         rules: []
-
-    - todo: "(XXX|TODO|FIXME|\\?\\?\\?)"