* Maintain integrity of the substitute and successor mappings when

deleting a path in the store.
* Allow absolute paths in Nix expressions.
* Get nix-prefetch-url to work again.
* Various other fixes.

src/libexpr/parser.hh

@@ -4,7 +4,13 @@
 #include "nixexpr.hh"
 
 
+/* Parse a Nix expression from the specified file.  If `path' refers
+   to a directory, the "/default.nix" is appended. */
 Expr parseExprFromFile(Path path);
 
+/* Parse a Nix expression from the specified string. */
+Expr parseExprFromString(const string & s,
+    const Path & basePath);
+
 
 #endif /* !__PARSER_H */