more snippets and a bug fix: strange (= nil nil) will cause error in elisp.

snippets/ruby-mode/#

@@ -0,0 +1,3 @@
+#name : # =>
+# --
+# => 

snippets/ruby-mode/am

@@ -0,0 +1,3 @@
+#name : alias_method new, old
+# --
+alias_method :${new_name}, :${old_name}

snippets/ruby-mode/case

@@ -0,0 +1,6 @@
+#name : case ... end
+# --
+case ${1:object}
+when ${2:condition}
+  $0
+end

snippets/ruby-mode/forin

@@ -0,0 +1,5 @@
+#name : for ... in ...; ... end
+# --
+for ${1:element} in ${2:collection}
+  $0
+end

snippets/ruby-mode/if

@@ -0,0 +1,5 @@
+#name : if ... end
+# --
+if ${1:condition}
+  $0
+end

snippets/ruby-mode/ife

@@ -0,0 +1,7 @@
+#name : if ... else ... end
+# --
+if ${1:condition}
+  $2
+else
+  $3
+end

snippets/ruby-mode/inject

@@ -0,0 +1,3 @@
+#name : inject(...) { |...| ... }
+# --
+inject(${1:0}) { |${2:injection}, ${3:element}| $0 }

snippets/ruby-mode/rb

@@ -0,0 +1,3 @@
+#name : /usr/bin/ruby -wKU
+# --
+#!/usr/bin/ruby -wKU

snippets/ruby-mode/reject

@@ -0,0 +1,3 @@
+#name : reject { |...| ... }
+# --
+reject { |${1:element}| $0 }

snippets/ruby-mode/select

@@ -0,0 +1,3 @@
+#name : select { |...| ... }
+# --
+select { |${1:element}| $0 }

yasnippet.el

@@ -27,7 +27,7 @@
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; User customizable variables
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-(defvar yas/key-syntaxes (list "w" "w_")
+(defvar yas/key-syntaxes (list "w" "w_" "w_." "^ ")
   "A list of syntax of a key. This list is tried in the order
 to try to find a key. For example, if the list is '(\"w\" \"w_\").
 And in emacs-lisp-mode, where \"-\" has the syntax of \"_\":
@@ -137,8 +137,9 @@ mode will be listed under the menu \"yasnippet\".")
 		     (yas/snippet-groups snippet)
 		     :test
 		     '(lambda (field group)
-			(= (yas/field-number field)
+			(and (not (null (yas/field-number field)))
-			   (yas/group-number group))))))
+			     (= (yas/field-number field)
+				(yas/group-number group)))))))
     (if group
 	(yas/group-add-field group field)
       (push (yas/make-group field snippet)