Ruby programs are written in 7-bit
ASCII.
[Ruby also has extensive support for Kanji,
using the
EUC, SJIS, or UTF-8 coding system. If a
code set
other than 7-bit ASCII is used, the KCODE option must be
set appropriately, as shown on page 137.]
Ruby is a line-oriented language. Ruby expressions and statements are
terminated at the end of a line unless the statement is obviously
incomplete---for example if the last token on a line is an operator or
comma.
A semicolon can be used to separate
multiple expressions on a line. You can also put a backslash at the
end of a line to continue it onto the next. Comments start
with `#' and run to the end of the
physical line. Comments are ignored during compilation.
a = 1
b = 2; c = 3
d = 4 + 5 + # no '\' needed
6 + 7
e = 8 + 9 \
+ 10 # '\' needed
|
Physical lines between a line starting with =begin and{=begin...=end@
{=begin documentation}
a line starting with =end are
ignored by the compiler and may be used for embedded documentation
(see Appendix A, which begins on page 511).
Ruby reads its program input in a single pass, so you can pipe
programs to the compiler's
stdin.
echo 'print "Hello\n"' | ruby
|
If the compiler comes across a line anywhere in the source containing
just ``
__END__'',
with no leading or trailing whitespace, it
treats that line as the end of the program---any subsequent lines will not be
compiled. However, these lines can be read into the running program
using the global
IO object
DATA, described
on page 217.
