Character to and from Integer Codes Conversion
AsciiToInt returns integer codes in 0:255
for each (one byte) character in strings. ichar is an
alias for it, for old S compatibility.
strcodes implements in R the basic engine for translating
characters to corresponding integer codes.
chars8bit() is the inverse function of
AsciiToint, producing “one byte” characters from integer
codes. Note that it (and hence strcodes() depends on the
locale, see Sys.getlocale().
AsciiToInt(strings)
ichar(strings)
chars8bit(i = 1:255)
strcodes(x, table = chars8bit(1:255))strings, x |
|
i |
numeric (integer) vector of values in |
table |
a vector of (unique) character strings, typically of one character each. |
Only codes in 1:127 make up the ASCII encoding which should be
identical for all R versions, whereas the ‘upper’ half
is often determined from the ISO-8859-1 (aka “ISO-Latin 1)”
encoding, but may well differ, depending on the locale setting, see
also Sys.setlocale.
Note that 0 is no longer allowed since, R does not allow
\0 aka nul characters in a string anymore.
AsciiToInt (and hence ichar) and chars8bit return a
vector of the same length as their argument.
Martin Maechler, partly in 1991 for S-plus
chars8bit(65:70)#-> "A" "B" .. "F"
stopifnot(identical(LETTERS, chars8bit(65:90)),
identical(AsciiToInt(LETTERS), 65:90))
## may only work in ISO-latin1 locale (not in UTF-8):
try( strcodes(c(a= "ABC", ch="1234", place = "Zürich")) )
## in "latin-1" gives {otherwise should give NA instead of 252}:
## Not run:
$a
[1] 65 66 67
$ch
[1] 49 50 51 52
$place
[1] 90 252 114 105 99 104
## End(Not run)
myloc <- Sys.getlocale()
if(.Platform $ OS.type == "unix") withAutoprint({ # ''should work'' here
try( Sys.setlocale(locale = "de_CH") )# "try": just in case
strcodes(c(a= "ABC", ch="1234", place = "Zürich")) # no NA hopefully
AsciiToInt(chars8bit()) # -> 1:255 {if setting latin1 succeeded above}
chars8bit(97:140)
try( Sys.setlocale(locale = "de_CH.utf-8") )# "try": just in case
chars8bit(97:140) ## typically looks different than above
})
## Resetting to original locale .. works "mostly":
lapply(strsplit(strsplit(myloc, ";")[[1]], "="),
function(cc) try(Sys.setlocale(cc[1], cc[2]))) -> .scratch
Sys.getlocale() == myloc # TRUE if we have succeeded to reset itPlease choose more modern alternatives, such as Google Chrome or Mozilla Firefox.