#ifndef __EVAL_H
#define __EVAL_H
#include <map>
#include "aterm.hh"
#include "nixexpr.hh"
namespace nix {
class Hash;
typedef std::map<Path, PathSet> DrvRoots;
typedef std::map<Path, Hash> DrvHashes;
/* Cache for calls to addToStore(); maps source paths to the store
paths. */
typedef std::map<Path, Path> SrcToStore;
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 */
SrcToStore srcToStore;
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);
/* Evaluate an expression, and recursively evaluate list elements and
attributes. If `canonicalise' is true, we remove things like
position information and make sure that attribute sets are in
sorded order. */
Expr strictEvalExpr(EvalState & state, Expr e,
bool canonicalise = false);
/* Specific results. */
string evalString(EvalState & state, Expr e, PathSet & context);
string evalStringNoCtx(EvalState & state, Expr e);
int evalInt(EvalState & state, Expr e);
bool evalBool(EvalState & state, Expr e);
ATermList evalList(EvalState & state, Expr e);
/* Flatten nested lists into a single list (or expand a singleton into
a list). */
ATermList flattenList(EvalState & state, Expr e);
/* String coercion. Converts strings, paths and derivations to a
string. If `coerceMore' is set, also converts nulls, integers,
booleans and lists to a string. */
string coerceToString(EvalState & state, Expr e, PathSet & context,
bool coerceMore = false, bool copyToStore = true);
/* Path coercion. Converts strings, paths and derivations to a path.
The result is guaranteed to be an canonicalised, absolute path.
Nothing is copied to the store. */
Path coerceToPath(EvalState & state, Expr e, PathSet & context);
/* Automatically call a function for which each argument has a default
value or has a binding in the `args' map. Note: result is a call,
not a normal form; it should be evaluated by calling evalExpr(). */
Expr autoCallFunction(Expr e, const ATermMap & args);
/* Print statistics. */
void printEvalStats(EvalState & state);
}
#endif /* !__EVAL_H */
