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Diffstat (limited to 'doc')
| -rw-r--r-- | doc/manual/src/language/values.md | 21 |
1 files changed, 12 insertions, 9 deletions
diff --git a/doc/manual/src/language/values.md b/doc/manual/src/language/values.md index f02ef2597..aa5455ae2 100644 --- a/doc/manual/src/language/values.md +++ b/doc/manual/src/language/values.md @@ -7,13 +7,16 @@ *Strings* can be written in three ways. The most common way is to enclose the string between double quotes, - e.g., `"foo bar"`. Strings can span multiple lines. The special - characters `"` and `\` and the character sequence `${` must be - escaped by prefixing them with a backslash (`\`). Newlines, carriage - returns and tabs can be written as `\n`, `\r` and `\t`, - respectively. + e.g., `"foo bar"`. Strings can span multiple lines. The backslash + (`\`) can be used to escape characters: newlines, carriage returns + and tabs may be written as `\n`, `\r` and `\t` respectively; any + other characters can be preceded by a backslash to remove any + special meaning they may have, like the special characters `"` and + `\` and the character sequence `${`. You can include the results of other expressions into a string by enclosing them in `${ }`, a feature known as [string interpolation]. + Due to a parser issue that has since come to be relied upon, the character sequence `$${` is interpreted literally and does not introduce an interpolation. + To express a `$` character immediately followed by an interpolation, the former must be escaped. [string interpolation]: ./string-interpolation.md @@ -43,16 +46,16 @@ Note that the whitespace and newline following the opening `''` is ignored if there is no non-whitespace text on the initial line. - Indented strings support [string interpolation]. - Since `${` and `''` have special meaning in indented strings, you need a way to quote them. `$` can be escaped by prefixing it with `''` (that is, two single quotes), i.e., `''$`. `''` can be escaped - by prefixing it with `'`, i.e., `'''`. `$` removes any special - meaning from the following `$`. Linefeed, carriage-return and tab + by prefixing it with `'`, i.e., `'''`. Linefeed, carriage-return and tab characters can be written as `''\n`, `''\r`, `''\t`, and `''\` escapes any other character. + Indented strings support [string interpolation] using `${ }` the same way regular strings do. + `$${` is interpreted literally in indented strings as well, so the `$` character must be escaped if it is to be followed by an interpolation. + Indented strings are primarily useful in that they allow multi-line string literals to follow the indentation of the enclosing Nix expression, and that less escaping is typically necessary for |