It seems that a combinations of character types can produce unexpected results for the resulting order of an explicit paste operation:
(x = paste(c('green','أحمر', 'أزرق'), collapse=' ')) # arabic for blue and red
#> [1] "green أحمر أزرق"
paste(x, 'yellow')
#> [1] "green أحمر أزرق yellow"
paste(x, 123)
#> [1] "green أحمر أزرق 123"
Is there any known solution to this - i.e. a way to ensure concatenation in the same sequence as the arguments are given? Perhaps the answer is don't concatenate different alphabets!
You may use the Unicode control characters 'left-to-right embedding',
u202A
("Treat the following text as embedded left-to-right"):See also Terminating Explicit Directional Embeddings and Overrides, (
u202C
), a thorough description on UNICODE BIDIRECTIONAL ALGORITHM, and here.