cc66237bf5
Addressing code-review comments.
96 lines
3.2 KiB
Plaintext
96 lines
3.2 KiB
Plaintext
= Command Parsing
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Kakoune commands, either loaded from a script or written in the command
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prompt, are parsed according to the following rules:
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== Basic parsing
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- Commands are terminated by a `;` or an end of line.
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- Words (command names and parameters) are delimited by whitespaces.
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== Quoted Strings
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If a word starts with `'`, `"`, or `%X` with `X` a _non-nestable_ punctuation
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character (see <<command-parsing#balanced-strings,Balanced Strings>> below for
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nestable characters), it is parsed as a quoted string whose delimiter is,
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respectively, `'`, `"`, or `X`.
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A quoted string contains every character (including whitespaces). Doubling
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a closing delimiter escapes it. Thus, for example, entering two closing
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delimiters at the end of a quoted string will render one of the characters
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literally; that is, it will be considered as part of the quoted string's
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content.
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Inside double quotes, `%`-strings are processed unless the `%` is escaped by
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doubling it. Double quotes inside these nested strings must also be escaped.
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No other escaping takes place in quoted strings.
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=== Quoted Strings Examples
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- `'foo'` contains *foo*.
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- `foo'bar'` is read verbatim, so it contains *foo'bar'*.
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- `foo%|bar|` is read verbatim, so it contains *foo%|bar|*.
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- `'foo''bar'` is a single word whose content is *foo'bar*.
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- `"baz"""` is a single word whose content is *baz"*.
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- `%|foo||bar|` is a single word whose content is *foo|bar*.
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- `"foo %|""bar| %%,baz,"` is a single word whose content is *foo "bar %,baz,*.
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== Balanced Strings
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If a word starts with `%X` with `X` a _nestable_ punctuation character (one
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of `(`, `[`, `{` and `<`), it is parsed as a balanced string whose closing
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delimiter matches that of its opening delimiter (respectively, `)`, `]`,
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`}`, and `>`).
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There is no way to escape the opening and closing characters, even if they
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are nested inside some other kind of string.
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=== Balanced Strings Examples
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- `%{foo}` contains *foo*.
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- `%{foo\{bar}}` contains *foo\{bar}*.
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- `foo%{bar}` contains *foo%{bar}*.
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- `"foo %{bar}"` is a single word whose content is *foo bar*.
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- `%{foo\{}` is a parse error, since the `{}` delimiters are not balanced.
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- `%[foo\{]` contains *foo\{*, since it uses different delimiters.
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== Non-Quoted words
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Other words are non-quoted. Non-quoted words are terminated by either a
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whitespace or a `;`.
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If they start with a `\` followed by a `%`, `'`, or `"`, then that leading
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`\` escapes those characters and is discarded.
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If a whitespace or `;` is preceded by a `\`, then the `\` is discarded, and
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the whitespace or `;` becomes part of the word. Any other `\` is treated
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as a literal `\`.
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== Typed Expansions
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Quoted and Balanced strings starting with `%` might have an optional
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alphabetic *expansion type* between the `%` and their delimiter (which is
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always a punctuation character). This *expansion type* defines how the
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string's content is going to be expanded. Rules for expanding and escaping
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expansion types are the same as for `%`-strings.
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- If the *expansion type* is empty, the string content is used verbatim.
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- If the *expansion type* is one of `sh`, `reg`, `opt`, `val` or `arg`,
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the string is expanded as described in <<expansions#,`:doc expansions`>>.
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- For any other *expansion type*, a parsing error is raised.
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