writing docs for java functions

java-src/io/github/erdos/stencil/functions/BasicFunctions.java

@@ -35,6 +35,12 @@ else if (expr != null && expr.equals(value))
                 return null;
             }
         }
+
+        @Override
+        public String getDocumentation() {
+            return "Select a value based on the first argument.\n"
+                    + "Usage: `switch(expression, case-1, value-1, case-2, value-2, ..., optional-default-value)`";
+        }
     },
 
     /**
@@ -50,6 +56,12 @@ public Object call(Object... arguments) {
                     return arg;
             return null;
         }
+
+        @Override
+        public String getDocumentation() {
+            return "Returns the first non-null or non-empty parameter.\n\n"
+                   + "Accepts any number of arguments. Ignores null values, empty string and empty collections.";
+        }
     },
 
     /**
@@ -67,6 +79,12 @@ public Object call(Object... arguments) {
                     || ((x instanceof Collection) && ((Collection) x).isEmpty())
                     || ((x instanceof Iterable) && !((Iterable) x).iterator().hasNext());
         }
+
+        @Override
+        public String getDocumentation() {
+            return "Returns true iff input is null, empty string or empty collection.\n\n"
+                    + "Expects exactly 1 parameter.";
+        }
     };
 
     @Override

java-src/io/github/erdos/stencil/functions/Function.java

@@ -26,4 +26,8 @@ public interface Function {
      * @return function identifier
      */
     String getName();
+
+    default String getDocumentation() {
+        return "Documentation is not available";
+    }
 }

scripts/generate-fun-docs.clj.sh

@@ -5,24 +5,34 @@ test ; set -e && cd "$(dirname "$0")/.." && clojure -M -i scripts/generate-fun-d
 
 ;; file is a regular CLJ script from now on
 
-(println "HALI")
-
 (require 'stencil.functions)
 
+(defn get-java-functions []
+  (for [f (.listFunctions (new io.github.erdos.stencil.functions.FunctionEvaluator))]
+    {:name (.getName f)
+     :docs (.getDocumentation f)}))
+
+(defn get-clj-functions []
+  (for [[k v] (methods stencil.functions/call-fn)]
+    {:name k
+     :docs (:stencil.functions/docs (meta v))}))
+
+(def all-functions
+  (sort-by :name (concat (get-java-functions) (get-clj-functions))))
+
 (println "# Functions")
 (println)
 (println "You can call functions from within the template files and embed the call result easily by writing `{%=functionName(arg1, arg2, arg3, ...)%}` expression in the document template.")
 (println "This page contains a short description of the functions implemented in Stencil.")
 (println)
 
-(doseq [k (sort (keys (methods stencil.functions/call-fn)))]
-  (printf "- [%s](#%s)\n" k k))
+;; Table of Contents
+(doseq [f all-functions]
+  (printf "- [%s](#%s)\n" (:name f) (:name f)))
 
 (println)
 
-(doseq [[k f] (sort (methods stencil.functions/call-fn))]
-  (printf "## %s\n\n" k)
-  (when-let [docs (:stencil.functions/docs (meta f))]
-    (println docs)
-    (println))
+(doseq [f all-functions]
+  (printf "## %s\n\n" (:name f))
+  (println (:docs f))
   (println))