format: Count prefix and suffix width in terms of display columns.

[pspp-builds.git] / src / data / format.h

diff --git a/src/data/format.h b/src/data/format.h
index 55643ab43d2678ccc1e4bb4a0fa0040cfad46ea7..7df374453def01b5392c2149c57bb203f2723d0e 100644 (file)
--- a/src/data/format.h
+++ b/src/data/format.h
@@ -146,7 +146,8 @@ void fmt_settings_set_style (struct fmt_settings *, enum fmt_type,
 /* A prefix or suffix for a numeric output format. */
 struct fmt_affix
   {
-    char *s;                    /* String contents of affix. */
+    char *s;                    /* String contents of affix, in UTF-8. */
+    int width;                  /* Display width in columns (see wcwidth()). */
   };
 
 /* A numeric output style. */
@@ -158,6 +159,15 @@ struct fmt_number_style
     struct fmt_affix neg_suffix; /* Negative suffix. */
     char decimal;                /* Decimal point: '.' or ','. */
     char grouping;               /* Grouping character: ',', '.', or 0. */
+
+    /* A fmt_affix may require more bytes than its display width; for example,
+       U+00A5 (¥) is 3 bytes in UTF-8 but occupies only one display column.
+       This member is the sum of the number of bytes required by all of the
+       fmt_affix members in this struct, minus their display widths.  Thus, it
+       can be used to size memory allocations: for example, the formatted
+       result of CCA20.5 requires no more than (20 + extra_bytes) bytes in
+       UTF-8. */
+    int extra_bytes;
   };
 
 int fmt_affix_width (const struct fmt_number_style *);