x-tco.c File Reference

The environment save and restore around a tail call. More...

#include "x-tco.h"
#include "x-eval.h"

Functions
x_obj_t *	x_tco_env_save (x_obj_t *p_base)
void	x_tco_restore (x_obj_t *p_base, x_obj_t *p_env)

Detailed Description

The environment save and restore around a tail call.

Author

Jon Ruttan (jonru.nosp@m.ttan.nosp@m.@gmai.nosp@m.l.co.nosp@m.m)

Copyright

2026 Jon Ruttan @license MIT No Attribution (MIT-0)

Function Documentation

x_tco_env_save()

x_obj_t * x_tco_env_save

(

x_obj_t *

p_base

)

Push the current environment onto the save-stack and return it.

A procedure call and eval-with-env snapshot the environment this way before making another one current; the trampoline, or x_eval_body_tco's early exits, put it back with x_tco_restore(). The environment is a value, so the snapshot is the pointer and nothing else – there is no boundary, tree or shadow list to carry beside it.

Parameters

p_base

x_obj_t* – Base (execution context)

Returns

x_obj_t* – The environment pushed

See also

x_tco_restore

x_tco_restore()

void x_tco_restore	(	x_obj_t *	p_base,
		x_obj_t *	p_env
	)

Make p_env the current environment.

Does NOT touch the save-stack – a caller that took the environment from the save-stack top pops it separately. This is the single restore used by both trampoline exit points (x_eval, x_eval_tco_trampoline), x_eval_body_tco's early-exit paths, eval-with-env, and the operative return.

Parameters

p_base	x_obj_t* – Base (execution context)
p_env	x_obj_t* – The environment to make current

See also

x_tco_env_save