guix/src/libnix/aterm.hh

56 lines
1.1 KiB
C++

#ifndef __ATERM_H
#define __ATERM_H
extern "C" {
#include <aterm2.h>
}
#include "util.hh"
/* Print an ATerm. */
string atPrint(ATerm t);
/* Write an ATerm to an output stream. */
ostream & operator << (ostream & stream, ATerm e);
/* Type-safe matching. */
struct ATMatcher
{
ATerm t;
int pos;
const static int failPos = -2;
const static int funPos = -1;
ATMatcher() : t(0), pos(failPos)
{
}
operator bool() const
{
return pos != failPos;
}
};
/* Initiate matching of a term. */
ATMatcher & atMatch(ATMatcher & pos, ATerm t);
/* Get the next argument of an application. */
ATMatcher & operator >> (ATMatcher & pos, ATerm & out);
/* Get the name of the function symbol of an applicatin, or the next
argument of an application as a string. */
ATMatcher & operator >> (ATMatcher & pos, string & out);
/* Like the previous, but check that the string is equal to the given
string. */
ATMatcher & operator >> (ATMatcher & pos, const string & s);
/* Get the next argument of an application, and verify that it is a
list. */
ATMatcher & operator >> (ATMatcher & pos, ATermList & out);
#endif /* !__ATERM_H */