#ifndef __NORMALISE_H
#define __NORMALISE_H

#include "storeexpr.hh"


/* Normalise a store expression.  That is, if the expression is a
   derivation, a path containing an equivalent closure expression is
   returned.  This requires that the derivation is performed, unless a
   successor is known. */
Path normaliseStoreExpr(const Path & nePath);

/* Realise a store expression.  If the expression is a derivation, it
   is first normalised into a closure.  The closure is then realised
   in the file system (i.e., it is ensured that each path in the
   closure exists in the file system, if necessary by using the
   substitute mechanism).  Returns the normal form of the expression
   (i.e., its closure expression). */
Path realiseStoreExpr(const Path & nePath);

/* Ensure that a path exists, possibly by instantiating it by
   realising a substitute. */
void ensurePath(const Path & path);

/* Read a store expression, after ensuring its existence through
   ensurePath(). */
StoreExpr storeExprFromPath(const Path & path);

/* Get the list of root (output) paths of the given store
   expression. */
PathSet storeExprRoots(const Path & nePath);

/* Get the list of paths that are required to realise the given store
   expression.  For a derive expression, this is the union of
   requisites of the inputs; for a closure expression, it is the path
   of each element in the closure.  If `includeExprs' is true, include
   the paths of the store expressions themselves.  If
   `includeSuccessors' is true, include the requisites of
   successors. */
PathSet storeExprRequisites(const Path & nePath,
    bool includeExprs, bool includeSuccessors);


#endif /* !__NORMALISE_H */