Struct Expander

pub struct Expander { /* private fields */ }

A set of options for expanding a template string using the contents of capture groups.

Implementations

impl Expander

pub fn python() -> Expander

Returns an expander that uses Python-compatible syntax.

Expands all instances of \num or \g<name> in replacement to the corresponding capture group num or name, and writes them to the dst buffer given.

name may be an integer corresponding to the index of the capture group (counted by order of opening parenthesis where \0 is the entire match) or it can be a name (consisting of letters, digits or underscores) corresponding to a named capture group.

num must be an integer corresponding to the index of the capture group.

If num or name isn’t a valid capture group (whether the name doesn’t exist or isn’t a valid index), then it is replaced with the empty string.

The longest possible number is used. e.g., \10 looks up capture group 10 and not capture group 1 followed by a literal 0.

To write a literal \, use \\.

pub fn check(&self, template: &str, regex: &Regex) -> Result<()>

Checks template for errors. The following conditions are checked for:

• A reference to a numbered group that does not exist in regex
• A reference to a numbered group (other than 0) when regex contains named groups
• A reference to a named group that does not occur in regex
• An opening group name delimiter without a closing delimiter
• Using an empty string as a group name

pub fn escape<'a>(&self, text: &'a str) -> Cow<'a, str>

Escapes the substitution character in text so it appears literally in the output of expansion.

assert_eq!(
    fancy_regex::Expander::default().escape("Has a literal $ sign."),
    "Has a literal $$ sign.",
);

pub fn expansion(&self, template: &str, captures: &Captures<'_>) -> String

Expands the template string template using the syntax defined by this expander and the values of capture groups from captures.

pub fn append_expansion( &self, dst: &mut String, template: &str, captures: &Captures<'_>, )

Appends the expansion produced by expansion to dst. Potentially more efficient than calling expansion directly and appending to an existing string.

pub fn write_expansion( &self, dst: impl Write, template: &str, captures: &Captures<'_>, ) -> Result<()>

Writes the expansion produced by expansion to dst. Potentially more efficient than calling expansion directly and writing the result.

pub fn write_expansion_vec( &self, dst: &mut Vec<u8>, template: &str, captures: &Captures<'_>, ) -> Result

Writes the expansion produced by expansion to dst. Potentially more efficient than calling expansion directly and writing the result.

Trait Implementations

impl Debug for Expander

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Expander

fn default() -> Self

Returns the default expander used by Captures::expand.