Improve some descriptions.

README.md

@@ -1,7 +1,7 @@
 Castile
 =======
 
-Version 0.4 | _Entry_ [@ catseye.tc](https://catseye.tc/node/Castile)
+Version 0.5 | _Entry_ [@ catseye.tc](https://catseye.tc/node/Castile)
 | _See also:_ [Eightebed](https://github.com/catseye/Eightebed#readme)
 ∘ [Dieter](https://github.com/catseye/Dieter#readme)
 

src/castile/main.py

@@ -1,6 +1,6 @@
 """castile {options} program-file.castile
 
-Interpreter/compiler for Castile, an unremarkable programming language.
+Interpreter/compiler for Castile, a programming language with union types.
 
 """
 
@@ -24,7 +24,7 @@ def main(argv):
                          dest="compile_to", default=None,
                          help="compile to given backend code instead "
                               "of evaluating directly (available backends: "
-                              "javascript, ruby, stackmac)")
+                              "c, javascript, ruby, stackmac)")
     optparser.add_option("-p", "--parse-only",
                          action="store_true", dest="parse_only",
                          default=False,

tests/Castile.md

@@ -362,15 +362,16 @@ Variables in upper scopes may be modified.
 
 ### Non-local Values ###
 
-Literals may appear at the toplevel.    Semicolons are optional at toplevel.
+Literals may appear at the toplevel.  Semicolons are optional at toplevel.
 
     | factor = 5;
     | fun main() {
     |   6 * factor
     | }
     = 30
 
-Toplevel literals may not be updated.  (And thus
+Toplevel literals may not be updated.  Thus, the following looks like it
+is defining a local with the same name as a toplevel, which is not permitted.
 
     | factor = 5
     | fun main() {