the ^EUq string building escape now respects the encoding (can insert bytes or codepoints) (refs #5)

* This is trickier than it sounds because there isn't one single place to consult.
  It depends on the context.
  If the string argument relates to buffer contents - as in <I>, <S>, <FR> etc. -
  the buffer's encoding is consulted.
  If it goes into a register (EU), the register's encoding is consulted.
  Everything else (O, EN, EC, ES...) expects only Unicode codepoints.
* This is communicated through a new field teco_machine_stringbuilding_t::codepage
  which must be set in the states' initial callback.
* Seems overkill just for ^EUq, but it can be used for context-sensitive
  processing of all the other string building constructs as well.
* ^V and ^W cannot be supported for Unicode characters for the time being without an Unicode-aware parser

1 files changed, 6 insertions, 0 deletions

diff --git a/doc/sciteco.7.template b/doc/sciteco.7.template
index a6cca40..ca23c93 100644
--- a/doc/sciteco.7.template
+++ b/doc/sciteco.7.template
@@ -1647,6 +1647,12 @@ Expands to the character whose code is stored in the numeric
 part of Q-Register \fIq\fP.
 For instance if register \(lqA\(rq contains the code 66,
 \(lq^EUa\(rq expands to the character \(lqB\(rq.
+The interpretation of this code depends on the context.
+Within inserts and searches (\fBI\fP, \fBS\fP, etc.) bytes or Unicode codepoints
+are expected depending on the buffer's encoding.
+Operations on registers (\fBEU\fP) similarily consult the
+register's encoding.
+Everything else expects Unicode codepoints.
 .TP
 .SCITECO_TOPIC ^EQ ^EQq
 .BI ^EQ q