nix-super/src/libexpr/eval.hh
Eelco Dolstra f4d44a0026 * Allow certain operations to succeed even if we don't have write
permission to the Nix store or database.  E.g., `nix-env -qa' will
  work, but `nix-env -qas' won't (the latter needs DB access).  The
  option `--readonly-mode' forces this mode; otherwise, it's only
  activated when the database cannot be opened.
2004-10-25 14:38:23 +00:00

54 lines
1.1 KiB
C++

#ifndef __EVAL_H
#define __EVAL_H
#include <map>
#include "aterm.hh"
#include "hash.hh"
#include "nixexpr.hh"
typedef map<Path, PathSet> DrvRoots;
typedef map<Path, Hash> DrvHashes;
struct EvalState;
/* Note: using a ATermVector is safe here, since when we call a primop
we also have an ATermList on the stack. */
typedef Expr (* PrimOp) (EvalState &, const ATermVector & args);
struct EvalState
{
ATermMap normalForms;
ATermMap primOps;
DrvRoots drvRoots;
DrvHashes drvHashes; /* normalised derivation hashes */
Expr blackHole;
unsigned int nrEvaluated;
unsigned int nrCached;
EvalState();
void addPrimOps();
void addPrimOp(const string & name,
unsigned int arity, PrimOp primOp);
};
/* Evaluate an expression to normal form. */
Expr evalExpr(EvalState & state, Expr e);
/* Evaluate an expression read from the given file to normal form. */
Expr evalFile(EvalState & state, const Path & path);
/* Specific results. */
string evalString(EvalState & state, Expr e);
Path evalPath(EvalState & state, Expr e);
/* Print statistics. */
void printEvalStats(EvalState & state);
#endif /* !__EVAL_H */