Struct bitcoin_internals::error::input_string::InputString

pub struct InputString(/* private fields */);

Conditionally stores the input string in parse errors.

This type stores the input string of a parse function depending on whether alloc feature is enabled. When it is enabled, the string is stored inside as String. When disabled this is a zero-sized type and attempt to store a string does nothing.

This provides two methods to format the error strings depending on the context.

Implementations

impl InputString

pub fn display_cannot_parse<'a, T>(&'a self, what: &'a T) -> CannotParse<'a, T>

where T: Display + ?Sized,

Displays a message saying failed to parse <self> as <what>.

This is normally used with the write_err! macro.

Examples

use core::fmt;
use bitcoin_internals::error::InputString;
use bitcoin_internals::write_err;

/// An example parsing error including the parse error from core.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct ParseError {
    input: InputString,
    error: core::num::ParseIntError,
}

impl fmt::Display for ParseError {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        // Outputs "failed to parse '<input string>' as foo"
        write_err!(f, "{}", self.input.display_cannot_parse("foo"); self.error)
    }
}

pub fn unknown_variant<T>(&self, what: &T, f: &mut Formatter<'_>) -> Result

where T: Display + ?Sized,

Formats a message saying <self> is not a known <what>.

This is normally used in leaf parse errors (with no source) when parsing an enum.

Examples

use core::fmt;
use bitcoin_internals::error::InputString;

/// An example parsing error.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct ParseError(InputString);

impl fmt::Display for ParseError {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        // Outputs "'<input string>' is not a known foo"
        self.0.unknown_variant("foo", f)
    }
}

Trait Implementations

impl Clone for InputString

fn clone(&self) -> InputString

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for InputString

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

Formats the value using the given formatter.

impl From<&str> for InputString

fn from(input: &str) -> Self

Converts to this type from the input type.

impl From<Box<str>> for InputString

Available on crate feature alloc only.

fn from(input: Box<str>) -> Self

Converts to this type from the input type.

impl From<Cow<'_, str>> for InputString

Available on crate feature alloc only.

fn from(input: Cow<'_, str>) -> Self

Converts to this type from the input type.

impl From<String> for InputString

Available on crate feature alloc only.

fn from(input: String) -> Self

Converts to this type from the input type.

impl Hash for InputString

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for InputString

fn cmp(&self, other: &InputString) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized + PartialOrd,

Restrict a value to a certain interval.

impl PartialEq for InputString

fn eq(&self, other: &InputString) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for InputString

fn partial_cmp(&self, other: &InputString) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl Eq for InputString

impl StructuralPartialEq for InputString