experimental 'highlight function

.gitignore

@@ -7,3 +7,5 @@ pom.xml.asc
 *.class
 /.lein-*
 /.nrepl-port
+*.sw*
+*~

README.md

@@ -1,14 +1,16 @@
 # clygments
 
-A Clojure library designed to ... well, that part is up to you.
+**clygments** is a Clojure bridge for [Pygments][].
+
+[Pygments]: http://pygments.org/
 
 ## Usage
 
 FIXME
 
 ## License
 
-Copyright © 2014 FIXME
+Copyright © 2014 Baptiste Fontaine
 
 Distributed under the Eclipse Public License either version 1.0 or (at
 your option) any later version.

project.clj

@@ -1,6 +1,8 @@
 (defproject clygments "0.1.0-SNAPSHOT"
-  :description "FIXME: write description"
-  :url "http://example.com/FIXME"
+  :description "Use Pygments from Clojure"
+  :url "http://github.com/bfontaine/clygments"
   :license {:name "Eclipse Public License"
             :url "http://www.eclipse.org/legal/epl-v10.html"}
-  :dependencies [[org.clojure/clojure "1.5.1"]])
+  :dependencies [[org.clojure/clojure          "1.5.1"]
+                 [org.python/jython-standalone "2.5.3"]
+                 [org.pygments/pygments        "1.5"]])

src/clygments/core.clj

@@ -1,6 +1,42 @@
-(ns clygments.core)
+(ns clygments.core
+  (:import [org.python.util PythonInterpreter]))
 
-(defn foo
-  "I don't do a whole lot."
-  [x]
-  (println x "Hello, World!"))
+(def ^{:private true} python
+  (doto (PythonInterpreter.)
+    (.exec (str "from pygments import highlight\n"
+                "from pygments.lexers import *\n"
+                "from pygments.formatters import *\n"))))
+
+(defn- exec-code-in
+  "put the result of the execution of a line of code in a variable, with
+   an optional default value if it encounters an exception"
+  ([var-name code]
+    (.exec python (str var-name "=" code)))
+  ([var-name code default]
+    (.exec python (str "try:\n\t" var-name "=" code "\n"
+                       "except:\n\t" var-name "=" default "\n"))))
+
+(def ^{:private true} py-true (.eval python "True"))
+(defn- py-true?
+  "test if an expression evals to True in Python"
+  [expr]
+  (= (.eval python expr) py-true))
+
+(defn highlight
+  "highlight a piece of code."
+  ([code] (highlight code :python :html))
+  ([code lang output]
+    (try
+      (exec-code-in "_r" (str "get_lexer_by_name(\"" (name lang) "\")") "None")
+      (exec-code-in
+        "_f" (str "get_formatter_by_name(\"" (name output) "\")") "None")
+      (if (and (py-true? "_r!=None") (py-true? "_f!=None"))
+        (do
+          ;; XXX it won't work if 'code contains a sequence of three or more
+          ;; double quotes, e.g.: """
+          (.exec python (str "_res=highlight(\"\"\"" code "\"\"\",_r,_f)\n"))
+          ;; XXX it won't work with non-text formatters, such as gif
+          (.get python "_res" String)))
+      (catch Exception e
+        (.printStackTrace e)
+        (println (.getMessage e))))))