patch 8.2.2233: cannot convert a byte index into a character index
Problem: Cannot convert a byte index into a character index.
Solution: Add charidx(). (Yegappan Lakshmanan, closes #7561)
diff --git a/runtime/doc/eval.txt b/runtime/doc/eval.txt
index 4c6636c..8b85dad 100644
--- a/runtime/doc/eval.txt
+++ b/runtime/doc/eval.txt
@@ -2475,6 +2475,8 @@
changenr() Number current change number
char2nr({expr} [, {utf8}]) Number ASCII/UTF8 value of first char in {expr}
charclass({string}) Number character class of {string}
+charidx({string}, {idx} [, {countcc}])
+ Number char index of byte {idx} in {string}
chdir({dir}) String change current working directory
cindent({lnum}) Number C indent for line {lnum}
clearmatches([{win}]) none clear all matches
@@ -3588,6 +3590,31 @@
other specific Unicode class
The class is used in patterns and word motions.
+ *charidx()*
+charidx({string}, {idx} [, {countcc}])
+ Return the character index of the byte at {idx} in {string}.
+ The index of the first character is zero.
+ If there are no multibyte characters the returned value is
+ equal to {idx}.
+ When {countcc} is omitted or zero, then composing characters
+ are not counted separately, their byte length is added to the
+ preceding base character.
+ When {countcc} is set to 1, then composing characters are
+ counted as separate characters.
+ Returns -1 if the arguments are invalid or if {idx} is greater
+ than the index of the last byte in {string}. An error is
+ given if the first argument is not a string, the second
+ argument is not a number or when the third argument is present
+ and is not zero or one.
+ See |byteidx()| and |byteidxcomp()| for getting the byte index
+ from the character index.
+ Examples: >
+ echo charidx('áb́ć', 3) returns 1
+ echo charidx('áb́ć', 6, 1) returns 4
+ echo charidx('áb́ć', 16) returns -1
+<
+ Can also be used as a |method|: >
+ GetName()->charidx(idx)
chdir({dir}) *chdir()*
Change the current working directory to {dir}. The scope of