streams: force-off indent mode.

The fourth indent mode indent-foff (force off) is introduced.

* buf.c (buf_print): Turn on data mode indentation if
the current mode is not indent-foff, rather than when it
is indent-off.

* lib.c (obj_print_impl): The unconditional set_indent_mode
calls are replaced with test_neq_set_indent_mode so we only
set the mode if it is not forced off.

* stream.c (formatv): For the ! directive, turn on data
mode identation is not indent-foff, rather than when it is
indent-off.
(put_string, put_char, width_check): Recognize ident-foff as
indentation off.
(test_neq_set_indent_mode): New function.
(stream_init): Register test-neq-set-indent-mode function
and indent-foff variable.

* stream.h (indent_mode): New enum constant, indent_foff.
(test_neq_set_indent_mode): Declared.

* struct.c (struct_inst_print): Turn on data mode indentation
if the current mode is not indent-foff, rather than when it is
indent-off.

* txr.1: Documented.

1 files changed, 3 insertions, 1 deletions

diff --git a/stream.h b/stream.h
index 37ab89a9..a7895064 100644
--- a/stream.h
+++ b/stream.h
@@ -34,7 +34,8 @@ enum strm_whence {
 enum indent_mode {
   indent_off,
   indent_data,
-  indent_code
+  indent_code,
+  indent_foff
 };
 
 struct strm_ctx {
@@ -205,6 +206,7 @@ val seek_stream(val stream, val offset, val whence);
 val truncate_stream(val stream, val len);
 val get_indent_mode(val stream);
 val test_set_indent_mode(val stream, val compare, val mode);
+val test_neq_set_indent_mode(val stream, val compare, val mode);
 val set_indent_mode(val stream, val mode);
 val get_indent(val stream);
 val set_indent(val stream, val indent);