Obtains an iterator pointing to @char_offset within the given line. The @char_offset must exist, offsets off the end of the line are not allowed. Note characters, not bytes; UTF-8 may encode one character as multiple bytes.
iterator to initialize
line number counting from 0
char offset from start of line
See Implementation
Obtains an iterator pointing to @char_offset within the given line. The @char_offset must exist, offsets off the end of the line are not allowed. Note characters, not bytes; UTF-8 may encode one character as multiple bytes.