miller/c/containers/bind_stack.h
2016-09-10 19:23:55 -04:00

45 lines
1.2 KiB
C

#ifndef BIND_STACK_H
#define BIND_STACK_H
#include "containers/mlrval.h"
#include "containers/lhmsmv.h"
// Bound & scoped variables for use in for-loops, function bodies, and
// subroutine bodies. A frame is 'fenced' if it's at entry to a
// function/subroutine body. Example:
//
// mlr ... put -f '
// func f(x) {
// return k;
// }
// for (k,v in $*) {
// $[k] = f(v)
// }
// '
//
// There is a bind-stack created on entering the put. A frame is pushed in the
// for-loop. A second frame is pushed in the call to f(x). The former should
// have access to k; the latter should not.
typedef struct _bind_stack_frame_t {
lhmsmv_t* bindings;
int fenced;
} bind_stack_frame_t;
typedef struct _bind_stack_t {
int num_used;
int num_allocated;
bind_stack_frame_t* pframes;
} bind_stack_t;
bind_stack_t* bind_stack_alloc();
void bind_stack_free(bind_stack_t* pstack);
void bind_stack_push(bind_stack_t* pstack, lhmsmv_t* bindings);
void bind_stack_push_fenced(bind_stack_t* pstack, lhmsmv_t* bindings);
void bind_stack_pop(bind_stack_t* pstack);
mv_t* bind_stack_resolve(bind_stack_t* pstack, char* key);
void bind_stack_print(bind_stack_t* pstack);
#endif // BIND_STACK_H