Struct serde_json_fmt::JsonFormat

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pub struct JsonFormat { /* private fields */ }

Expand description

A Formatter builder for configuring JSON serialization options.

This type is the “entry point” to serde-json-fmt’s functionality. To perform custom-formatted JSON serialization, start by creating a JsonFormat instance by calling either JsonFormat::new() or JsonFormat::pretty(), then call the various configuration methods as desired, then either pass your serde::Serialize value to one of the format_to_string(), format_to_vec(), and format_to_writer() convenience methods or else (for lower-level usage) call build() or as_formatter() to acquire a serde_json::ser::Formatter instance.

Implementations§

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impl JsonFormat

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pub fn new() -> Self

Create a new JsonFormat instance that starts out configured to use serde_json’s “compact” format. Specifically, the instance is configured as follows:

indent(None)
comma(",")
colon(":")
ascii(false)

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pub fn pretty() -> Self

Create a new JsonFormat instance that starts out configured to use serde_json’s “pretty” format. Specifically, the instance is configured as follows:

indent(Some(" ")) (two spaces)
comma(",")
colon(": ")
ascii(false)

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pub fn ascii(self, flag: bool) -> Self

Set whether non-ASCII characters in strings should be serialized as ASCII using \uXXXX escape sequences. If flag is true, then all non-ASCII characters will be escaped; if flag is false, then non-ASCII characters will be serialized as themselves.

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pub fn comma<S: AsRef<str>>(self, s: S) -> Result<Self, JsonSyntaxError>

Set the string to use as the item separator in lists & objects.

s must contain exactly one comma (,) character; all other characters must be space characters, tabs, line feeds, and/or carriage returns.

Errors

Returns Err if s does not meet the above requirements.

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pub fn colon<S: AsRef<str>>(self, s: S) -> Result<Self, JsonSyntaxError>

Set the string to use as the key-value separator in objects.

s must contain exactly one colon (:) character; all other characters must be space characters, tabs, line feeds, and/or carriage returns.

Errors

Returns Err if s does not meet the above requirements.

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pub fn indent<S: AsRef<str>>( self, s: Option<S> ) -> Result<Self, JsonSyntaxError>

Set the string used for indentation.

If s is None, then no indentation or newlines will be inserted when serializing. If s is Some("") (an empty string), then newlines will be inserted, but nothing will be indented. If s contains any other string, the string must consist entirely of space characters, tabs, line feeds, and/or carriage returns.

Errors

Returns Err if s contains a string that contains any character other than those listed above.

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pub fn indent_width(self, n: Option<usize>) -> Self

Set the string used for indentation to the given number of spaces.

This method is a convenience wrapper around indent() that calls it with a string consisting of the given number of space characters, or with None if n is None.

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pub fn format_to_string<T: ?Sized + Serialize>( &self, value: &T ) -> Result<String, Error>

Format a serde::Serialize value to a String as JSON using the configured formatting options.

Errors

Has the same error conditions as serde_json::to_string().

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pub fn format_to_vec<T: ?Sized + Serialize>( &self, value: &T ) -> Result<Vec<u8>, Error>

Format a serde::Serialize value to a Vec<u8> as JSON using the configured formatting options.

Errors

Has the same error conditions as serde_json::to_vec().

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pub fn format_to_writer<T: ?Sized + Serialize, W: Write>( &self, writer: W, value: &T ) -> Result<(), Error>

Write a serde::Serialize value to a std::io::Write instance as JSON using the configured formatting options.

Errors

Has the same error conditions as serde_json::to_writer().

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pub fn build(self) -> JsonFormatter

Consume the JsonFormat instance and return a serde_json::ser::Formatter instance.

This is a low-level operation. For most use cases, using one of the format_to_string(), format_to_vec(), and format_to_writer() convenience methods is recommended.

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pub fn as_formatter(&self) -> JsonFrmtr<'_>

Return a serde_json::ser::Formatter instance that borrows data from the JsonFormat instance.

This is a low-level operation. For most use cases, using one of the format_to_string(), format_to_vec(), and format_to_writer() convenience methods is recommended.

Unlike build(), this method makes it possible to create multiple Formatters from a single JsonFormat instance.