Services fixes, and a standard JSON API.

web.py

@@ -56,5 +56,16 @@ def entity(match):
 def decode(html): 
    return r_entity.sub(entity, html)
 
+r_string = re.compile(r'("(\\.|[^"\\])*")')
+r_json = re.compile(r'^[,:{}\[\]0-9.\-+Eaeflnr-u \n\r\t]+$')
+env = {'__builtins__': None, 'null': None, 'true': True, 'false': False}
+
+def json(text): 
+   """Evaluate JSON text safely (we hope)."""
+   if r_json.match(r_string.sub('', text)): 
+      text = r_string.sub(lambda m: 'u' + m.group(1), text)
+      return eval(text.strip(' \t\r\n'), env, {})
+   raise ValueError('Input must be serialised JSON.')
+
 if __name__=="__main__": 
    main()