Struct debug2::Formatter

pub struct Formatter<'a> { /* private fields */ }

Configuration for formatting.

A Formatter represents various options related to formatting. Users do not construct Formatters directly; a mutable reference to one is passed to the fmt method of Debug.

To interact with a Formatter, you’ll call various methods to change the various options related to formatting. For examples, please see the documentation of the methods defined on Formatter below.

Implementations

impl<'a> Formatter<'a>

pub fn debug_struct<'b>(&'b mut self, name: &str) -> DebugStruct<'b, 'a>

Creates a DebugStruct builder designed to assist with creation of Debug implementations for structs.

Examples

use debug2::{pprint, Debug, Formatter};
use std::fmt;
use std::net::Ipv4Addr;

struct Foo {
    bar: i32,
    baz: String,
    addr: Ipv4Addr,
}

impl Debug for Foo {
    fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
        fmt.debug_struct("Foo")
            .field("bar", &self.bar)
            .field("baz", &self.baz)
            .field("addr", &format!("{}", self.addr))
            .finish()
    }
}

assert_eq!(
    "Foo { bar: 10, baz: \"Hello World\", addr: \"127.0.0.1\" }",
    pprint(Foo {
        bar: 10,
        baz: "Hello World".to_string(),
        addr: Ipv4Addr::new(127, 0, 0, 1),
    })
);

pub fn debug_tuple<'b>(&'b mut self, name: &str) -> DebugTuple<'b, 'a>

Creates a DebugTuple builder designed to assist with creation of Debug implementations for tuple structs.

Examples

use debug2::{pprint, Debug, Formatter};
use std::fmt;
use std::marker::PhantomData;

struct Foo<T>(i32, String, PhantomData<T>);

impl<T> Debug for Foo<T> {
    fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
        fmt.debug_tuple("Foo")
            .field(&self.0)
            .field(&self.1)
            .field(&format!("_"))
            .finish()
    }
}

assert_eq!(
    "Foo(10, \"Hello\", \"_\")",
    pprint(Foo(10, "Hello".to_string(), PhantomData::<u8>))
);

pub fn debug_list<'b>(&'b mut self) -> DebugList<'b, 'a>

Creates a DebugList builder designed to assist with creation of Debug implementations for list-like structures.

Examples

use debug2::{pprint, Debug, Formatter};
use std::fmt;

struct Foo(Vec<i32>);

impl Debug for Foo {
    fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
        fmt.debug_list().entries(self.0.iter()).finish()
    }
}

assert_eq!(pprint(Foo(vec![10, 11])), "[10, 11]");

pub fn debug_set<'b>(&'b mut self) -> DebugSet<'b, 'a>

Creates a DebugSet builder designed to assist with creation of Debug implementations for set-like structures.

Examples

use debug2::{pprint, Debug, Formatter};
use std::fmt;

struct Foo(Vec<i32>);

impl Debug for Foo {
    fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
        fmt.debug_set().entries(self.0.iter()).finish()
    }
}

assert_eq!(pprint(Foo(vec![10, 11])), "{10, 11}");

pub fn debug_map<'b>(&'b mut self) -> DebugMap<'b, 'a>

Creates a DebugMap builder designed to assist with creation of Debug implementations for map-like structures.

Examples

use debug2::{pprint, Debug, Formatter};
use std::fmt;

struct Foo(Vec<(String, i32)>);

impl Debug for Foo {
    fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
        fmt.debug_map()
            .entries(self.0.iter().map(|&(ref k, ref v)| (k, v)))
            .finish()
    }
}

assert_eq!(
    pprint(Foo(vec![("A".to_string(), 10), ("B".to_string(), 11)])),
    r#"{"A": 10, "B": 11}"#
);