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#ifndef __NIXEXPR_H
#define __NIXEXPR_H
#include <map>
#include "types.hh"
namespace nix {
MakeError(EvalError, Error)
MakeError(ParseError, Error)
MakeError(AssertionError, EvalError)
MakeError(ThrownError, AssertionError)
MakeError(Abort, EvalError)
MakeError(TypeError, EvalError)
struct Pos
{
string file;
unsigned int line, column;
};
/* Abstract syntax of Nix expressions. */
struct Env;
struct Value;
struct EvalState;
struct Expr
{
virtual void show(std::ostream & str) = 0;
virtual void eval(EvalState & state, Env & env, Value & v)
{
throw Error("not implemented");
}
};
std::ostream & operator << (std::ostream & str, Expr & e);
#define COMMON_METHODS \
void show(std::ostream & str); \
void eval(EvalState & state, Env & env, Value & v);
struct ExprInt : Expr
{
int n;
ExprInt(int n) : n(n) { };
COMMON_METHODS
};
struct ExprString : Expr
{
string s;
ExprString(const string & s) : s(s) { };
COMMON_METHODS
};
struct ExprPath : Expr
{
string s;
ExprPath(const string & s) : s(s) { };
COMMON_METHODS
};
struct ExprVar : Expr
{
string name;
ExprVar(const string & name) : name(name) { };
COMMON_METHODS
};
struct ExprSelect : Expr
{
Expr * e;
string name;
ExprSelect(Expr * e, const string & name) : e(e), name(name) { };
COMMON_METHODS
};
struct ExprAttrs : Expr
{
bool recursive;
typedef std::map<string, Expr *> Attrs;
Attrs attrs;
list<string> inherited;
ExprAttrs() : recursive(false) { };
COMMON_METHODS
};
struct ExprList : Expr
{
std::vector<Expr *> elems;
ExprList() { };
COMMON_METHODS
};
struct Formal
{
string name;
Expr * def;
Formal(const string & name, Expr * def) : name(name), def(def) { };
};
struct Formals
{
typedef std::list<Formal> Formals_;
Formals_ formals;
bool ellipsis;
};
struct ExprLambda : Expr
{
Pos pos;
string arg;
bool matchAttrs;
Formals * formals;
Expr * body;
ExprLambda(const Pos & pos, const string & arg, bool matchAttrs, Formals * formals, Expr * body)
: pos(pos), arg(arg), matchAttrs(matchAttrs), formals(formals), body(body) { };
COMMON_METHODS
};
struct ExprWith : Expr
{
Pos pos;
Expr * attrs, * body;
ExprWith(const Pos & pos, Expr * attrs, Expr * body) : pos(pos), attrs(attrs), body(body) { };
COMMON_METHODS
};
struct ExprIf : Expr
{
Expr * cond, * then, * else_;
ExprIf(Expr * cond, Expr * then, Expr * else_) : cond(cond), then(then), else_(else_) { };
COMMON_METHODS
};
#define MakeBinOp(name, s) \
struct Expr##name : Expr \
{ \
Expr * e1, * e2; \
Expr##name(Expr * e1, Expr * e2) : e1(e1), e2(e2) { }; \
void show(std::ostream & str) \
{ \
str << *e1 << " " s " " << *e2; \
} \
void eval(EvalState & state, Env & env, Value & v); \
};
MakeBinOp(App, "")
MakeBinOp(OpEq, "==")
MakeBinOp(OpNEq, "!=")
MakeBinOp(OpAnd, "&&")
MakeBinOp(OpOr, "||")
MakeBinOp(OpImpl, "->")
MakeBinOp(OpUpdate, "//")
MakeBinOp(OpConcatStrings, "+")
MakeBinOp(OpConcatLists, "++")
#if 0
/* Show a position. */
string showPos(ATerm pos);
/* Generic bottomup traversal over ATerms. The traversal first
recursively descends into subterms, and then applies the given term
function to the resulting term. */
struct TermFun
{
virtual ~TermFun() { }
virtual ATerm operator () (ATerm e) = 0;
};
ATerm bottomupRewrite(TermFun & f, ATerm e);
/* Create an attribute set expression from an Attrs value. */
Expr makeAttrs(const ATermMap & attrs);
/* Check whether all variables are defined in the given expression.
Throw an exception if this isn't the case. */
void checkVarDefs(const ATermMap & def, Expr e);
#endif
}
#endif /* !__NIXEXPR_H */
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