6d6c68c0d2
single quotes. Example (from NixOS):
job = ''
start on network-interfaces
start script
rm -f /var/run/opengl-driver
${if videoDriver == "nvidia"
then "ln -sf ${nvidiaDrivers} /var/run/opengl-driver"
else if cfg.driSupport
then "ln -sf ${mesa} /var/run/opengl-driver"
else ""
}
rm -f /var/log/slim.log
end script
'';
This style has two big advantages:
- \, ' and " aren't special, only '' and ${. So you get a lot less
escaping in shell scripts / configuration files in Nixpkgs/NixOS.
The delimiter '' is rare in scripts (and can usually be written as
""). ${ is also fairly rare.
Other delimiters such as <<...>>, {{...}} and <|...|> were also
considered but this one appears to have the fewest drawbacks
(thanks Martin).
- Indentation is intelligently stripped so that multi-line strings
can follow the nesting structure of the containing Nix
expression. E.g. in the example above 6 spaces are stripped from
the start of each line. This prevents unnecessary indentation in
generated files (which sometimes even breaks things).
See tests/lang/eval-okay-ind-string.nix for some examples.
|
||
|---|---|---|
| .. | ||
| Makefile.am | ||
| attr-path.cc | ||
| attr-path.hh | ||
| common-opts.cc | ||
| common-opts.hh | ||
| eval.cc | ||
| eval.hh | ||
| expr-to-xml.cc | ||
| expr-to-xml.hh | ||
| get-drvs.cc | ||
| get-drvs.hh | ||
| lexer.l | ||
| nix.sdf | ||
| nixexpr-ast.def | ||
| nixexpr.cc | ||
| nixexpr.hh | ||
| parser.hh | ||
| parser.y | ||
| primops.cc | ||