flcl_manual-flcl_commands-conv-read-input-save-file-cnv-chr-nonchr

NONCHR

Synopsis

HELP:   How to handle non-character Unicode codepoints
TYPE:   NUMBER
SYNTAX: NONCHR=KEEP/REPLACE/SUBSTITUTE/IGNORE

Description

There 66 codepoints in Unicode that are defined as noncharacters. These codepoints do not have a visual representation and are reserved for internal use.

This switch controls how to deal with noncharacter codepoints. It only has an effect if the input is encoded in any Unicode charset (UTF/UCS).

There are three options:

KEEP: Noncharacter codepoints are left untouched.
REPLACE: Replace any noncharacter with the replacement character (U+FFFD)
IGNORE: Ignore noncharacter codepoints, which effectively removes them

Character conversion might fail if there is no corresponding representation for the respective noncharacter (if KEEP is selected) or for the replacement character (if REPLACE is selected) in the destination charset.

More details on noncharacters can be found here (section "Noncharacters"): https://www.unicode.org/faq/private_use.html

Selections

KEEP - Keep any codepoints of the Unicode noncharacters class
REPLACE - Replace noncharacter codepoints with the replacement character (U+FFFD)
SUBSTITUTE - Replace noncharacter codepoints with the substitution character (U+1A)
IGNORE - Ignore/remove noncharacter codepoints