* Is CHAR_TO_BYTE considered to have no side-effects?
@ 2002-04-17 14:30 Juanma Barranquero
2002-04-18 18:44 ` Richard Stallman
0 siblings, 1 reply; 2+ messages in thread
From: Juanma Barranquero @ 2002-04-17 14:30 UTC (permalink / raw)
The following patch removes two unused local variables from
current_column_1 and Fmove_to_column, but is is conditional on supposing
CHAR_TO_BYTE has no side effects.
In fact it can have, has CHAR_TO_BYTE hides a call to
buf_charpos_to_bytepos, which in turn can potentially make things like
creating (short-lived) markers for caching, etc.
So, can CHAR_TO_BYTE be considered, interface-wise, as side-effect free?
/L/e/k/t/u
Index: indent.c
===================================================================
RCS file: /cvs/emacs/src/indent.c,v
retrieving revision 1.148
diff -u -r1.148 indent.c
--- indent.c 17 Apr 2002 14:19:00 -0000 1.148
+++ indent.c 17 Apr 2002 14:20:46 -0000
@@ -512,7 +512,7 @@
/* Start the scan at the beginning of this line with column number 0. */
register int col = 0;
int scan, scan_byte;
- int next_boundary, next_boundary_byte;
+ int next_boundary;
int opoint = PT, opoint_byte = PT_BYTE;
scan_newline (PT, PT_BYTE, BEGV, BEGV_BYTE, -1, 1);
@@ -520,7 +520,6 @@
scan = PT, scan_byte = PT_BYTE;
SET_PT_BOTH (opoint, opoint_byte);
next_boundary = scan;
- next_boundary_byte = scan_byte;
if (tab_width <= 0 || tab_width > 1000) tab_width = 8;
@@ -540,7 +539,6 @@
goto endloop;
if (scan != old_scan)
scan_byte = CHAR_TO_BYTE (scan);
- next_boundary_byte = CHAR_TO_BYTE (next_boundary);
}
/* Check composition sequence. */
@@ -937,8 +935,7 @@
int prev_col = 0;
int c = 0;
int next_boundary;
-
- int pos_byte, next_boundary_byte;
+ int pos_byte;
if (tab_width <= 0 || tab_width > 1000) tab_width = 8;
CHECK_NATNUM (column);
@@ -948,7 +945,6 @@
pos_byte = PT_BYTE;
end = ZV;
next_boundary = pos;
- next_boundary_byte = PT_BYTE;
/* If we're starting past the desired column,
back up to beginning of line and scan from there. */
@@ -968,7 +964,6 @@
pos = skip_invisible (pos, &next_boundary, end, Qnil);
if (pos != prev)
pos_byte = CHAR_TO_BYTE (pos);
- next_boundary_byte = CHAR_TO_BYTE (next_boundary);
if (pos >= end)
goto endloop;
}
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: Is CHAR_TO_BYTE considered to have no side-effects?
2002-04-17 14:30 Is CHAR_TO_BYTE considered to have no side-effects? Juanma Barranquero
@ 2002-04-18 18:44 ` Richard Stallman
0 siblings, 0 replies; 2+ messages in thread
From: Richard Stallman @ 2002-04-18 18:44 UTC (permalink / raw)
Cc: emacs-devel
So, can CHAR_TO_BYTE be considered, interface-wise, as side-effect free?
For most purposes, yes. Unless the surrounding code operates directly
on the marker data structures in a way that might be fooled by
creating new markers, it is ok.
^ permalink raw reply [flat|nested] 2+ messages in thread
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