Support max length and depth for object printing.

* hash.c (hash_print_op): Implement max length.

* lib.c (lazy_str_put, out_lazy_str): Take struct strm_base *
parameter and implement max length.
(out_quasi_str_sym): Don't use obj_print_impl for symbol's
name string; just put_string. The use of obj_print_impl causes
symbols appearing as variables in quasiliterals to be
truncated when max length is imposed.
(out_quasi_str): Implement max length.
(obj_print_impl): Implement max length and depth. Note that
there is now always a non-null ctx pointer.
(obj_print): Always set up context pointer for obj_print_impl.
Context now has pointer to low-level stream structure, where
we can access max_length and max_depth. It also carries the
recursion depth.

* lib.h (lazy_str_put): Declaration updated.

* stream.c (strm_base_init): Add initializers for max_length
and max_depth.
(put_string): Pass stream structure to lazy_str_put.
(set_max_length, set_max_depth): New functions.
(stream_init): set-max-length and set-max-depth intrinsics
registered.

* stream.h (struct strm_ctx): New members depth and strm.
(struct strm_base): New members max_length and max_depth.
(set_max_length, set_max_depth): Declared.

* txr.1: Documented.

1 files changed, 6 insertions, 0 deletions

diff --git a/stream.h b/stream.h
index a7895064..cba0330a 100644
--- a/stream.h
+++ b/stream.h
@@ -42,6 +42,8 @@ struct strm_ctx {
   val obj_hash;
   val obj_hash_prev;
   val counter;
+  cnum depth;
+  struct strm_base *strm;
 };
 
 struct strm_base {
@@ -51,6 +53,8 @@ struct strm_base {
   cnum indent_chars;
   cnum column;
   unsigned force_break;
+  cnum max_length;
+  cnum max_depth;
   struct strm_ctx *ctx;
 };
 
@@ -213,6 +217,8 @@ val set_indent(val stream, val indent);
 val inc_indent(val stream, val delta);
 val width_check(val stream, val alt);
 val force_break(val stream);
+val set_max_length(val stream, val length);
+val set_max_depth(val stream, val depth);
 struct strm_ctx *get_set_ctx(val stream, struct strm_ctx *);
 struct strm_ctx *get_ctx(val stream);
 val get_string(val stream, val nchars, val close_after_p);