Add clsx utility

# Conflicts:
#	README.md

README.md

@@ -1,8 +1,10 @@
 # HSX – Hypertext S-expression
 
-**HSX** is a lightweight and expressive HTML generation library for Common Lisp, inspired by JSX. It allows you to write HTML using native Lisp syntax via S-expressions.
+**HSX** is a simple and powerful HTML generation library for Common Lisp, inspired by JSX. It allows you to write HTML using native Lisp syntax.
 
-> 🚧 **ALPHA NOTICE:**  
+[Practical usage example](https://github.com/skyizwhite/website)
+
+> 🚧 **BETA NOTICE:**  
 > This library is still in early development. APIs may change.  
 > See [release notes](https://github.com/skyizwhite/hsx/releases) for details.
 
@@ -26,28 +28,26 @@ For example:
 Is internally transformed (by macro expansion) into:
 
 ```lisp
-(create-element :article '(:class "container")
+(create-element :article
-  (list
+                (list :class "container")
-    (create-element :h1 nil (list "Title"))
+                (list (create-element :h1
-    (create-element :p nil (list "Paragraph"))
+                                      (list)
-    (create-element #'~share-button '(:service :x) (list))))
+                                      (list "Title"))
+                      (create-element :p
+                                      (list)
+                                      (list "Paragraph"))
+                      (create-element #'~share-button
+                                      (list :service :x)
+                                      (list))))
 ```
 
-This is made possible via the hsx macro, which detects HTML tags and components, then rewrites them using create-element. Tags are converted to keywords (e.g., div → :div), and custom components (starting with ~) are passed as functions.
-
-This uniform representation allows rendering, manipulation, and analysis of the HTML structure in a Lisp-friendly way.
-
-
 ## 🚀 Quick Example
 
 ```lisp
 (hsx
   (div :id "main" :class "container"
     (h1 "Hello, HSX!")
-    (p "This is a simple paragraph.")
+    (p "This is a simple paragraph.")))
-    (ul
-      (loop for i from 1 to 3 collect
-        (hsx (li (format nil "Item ~a" i)))))))
 ```
 
 Generates:
@@ -56,11 +56,6 @@ Generates:
 <div id="main" class="container">
   <h1>Hello, HSX!</h1>
   <p>This is a simple paragraph.</p>
-  <ul>
-    <li>Item 1</li>
-    <li>Item 2</li>
-    <li>Item 3</li>
-  </ul>
 </div>
 ```
 
@@ -73,7 +68,7 @@ Use `render-to-string` to convert an HSX structure to a string of HTML:
   (hsx ...))
 ``` 
 
-## 🔐 Escaping Behavior
+## 🔐 Escaping text
 
 All elements automatically escape special characters in content to prevent XSS and HTML injection:
 
@@ -176,13 +171,15 @@ Or loop:
       (hsx (li item))))))
 ```
 
-## 🏷️ Built-in Tags
+## Utils
 
-All standard HTML5 tags (and a few extras like `<>`, `raw!`) are automatically defined and exported from the hsx package. You don’t need to declare them manually.
+- `(clsx &rest strs)`: A utility function for constructing class strings conditionally. It removes `nil` from the string list, then joins the remaining strings with spaces.
 
 ## 📄 License
 
 MIT License
-	•	© 2024 Akira Tempaku
+
-	•	© 2018 Bo Yao (original [flute](https://github.com/ailisp/flute) project)
+© 2024 Akira Tempaku
+
+© 2018 Bo Yao (original [flute](https://github.com/ailisp/flute) project)
  

hsx.asd

@@ -1,5 +1,5 @@
 (defsystem "hsx"
-  :version "0.5.0"
+  :version "0.6.0"
   :description "Simple and powerful HTML generation library."
   :author "Akira Tempaku, Bo Yao"
   :maintainer "Akira Tempaku <paku@skyizwhite.dev>"

src/main.lisp

@@ -2,9 +2,11 @@
   (:nicknames #:hsx/main)
   (:use #:cl
         #:hsx/element
-        #:hsx/dsl)
+        #:hsx/dsl
+        #:hsx/utils)
   (:import-from #:hsx/builtin)
   (:export #:hsx
            #:defcomp
-           #:render-to-string))
+           #:render-to-string
+           #:clsx))
 (in-package :hsx)

src/utils.lisp

@@ -5,7 +5,8 @@
                 #:make-keyword
                 #:symbolicate)
   (:export #:escape-html-attribute
-           #:escape-html-text-content))
+           #:escape-html-text-content
+           #:clsx))
 (in-package #:hsx/utils)
 
 (defparameter *text-content-escape-map*
@@ -40,3 +41,6 @@
 
 (defun escape-html-attribute (str)
   (escape-string str *attribute-escape-map*))
+
+(defun clsx (&rest strs)
+  (format nil "~{~a~^ ~}" (remove nil strs)))