macros: templating macros

mustache syntax
if, when blocks
chaining properties
define variables

1 files changed, 50 insertions, 0 deletions

diff --git a/macros.lisp b/macros.lisp
index 85f2c9d..0245fdb 100644
--- a/macros.lisp
+++ b/macros.lisp
@@ -4,3 +4,53 @@
   `(list :script 
          (list :raw 
                (ps ,@body))))
+
+;; Templating macros
+(defmacro mu (&rest body)
+  "Macro writing Mustache syntax, namely the '{{ mustache }}'"
+  `(list :raw (concatenate 'string "{{ " ,@body " }}")))
+
+(defun keyword-to-chain (string-or-keyword)
+  (if (keywordp string-or-keyword)
+    (concatenate 'string "."
+                 (-> string-or-keyword
+                     symbol-name
+                     string-downcase))
+    string-or-keyword))
+
+(defun muc (&rest chain-of-props)
+  "Shortcut chaining props in a mustache"
+  (mu (reduce (lambda (a b) 
+                (concatenate 'string 
+                             (keyword-to-chain a) 
+                             (keyword-to-chain b)))
+        chain-of-props)))
+
+(defmacro mublock (name attrs &rest body)
+  "Macro writing a block where a '{{ end }}' is followed."
+  `(list
+    (mu ,name " " ,attrs)
+    ,@(mapcar (lambda (x) `',x) body)
+    (mu "end")))
+
+(defmacro muwhen (condition &rest body)
+  `(mublock "if" ,condition ,@body))
+
+(defmacro muif (condition do do-else)
+  `(muwhen ,condition 
+           (values ,do)
+           (list :RAW (mu "else"))
+           (values ,do-else)))
+
+(defun quote-if-string (str)
+  (if (stringp str) 
+    (concatenate 'string "\"" str "\"")
+    (write-to-string str)))
+
+;; TODO support function calls as values
+(defmacro mudefvar (var val)
+  `(mu "$" 
+       (string-downcase (symbol-name ',var)) 
+       " := " 
+       (quote-if-string ,val)))
+