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//! Wrap the low-level API into idiomatic serializers. use super::result::Result; use super::num::Number; // HELPERS /// Map partial result to complete result. macro_rules! to_complete { ($cb:expr, $bytes:expr, $radix:expr) => { match $cb($bytes, $radix) { Err(e) => Err(e), Ok((value, processed)) => if processed == $bytes.len() { Ok(value) } else{ Err((ErrorCode::InvalidDigit, processed).into()) } } }; } // FROM LEXICAL /// Trait for numerical types that can be parsed from bytes. pub trait FromLexical: Number { /// Checked parser for a string-to-number conversion. /// /// This method parses the entire string, returning an error if /// any invalid digits are found during parsing. /// /// Returns a `Result` containing either the parsed value, /// or an error containing any errors that occurred during parsing. /// /// Numeric overflow takes precedence over the presence of an invalid /// digit, and therefore may mask an invalid digit error. /// /// * `bytes` - Slice containing a numeric string. fn from_lexical(bytes: &[u8]) -> Result<Self>; /// Checked parser for a string-to-number conversion. /// /// This method parses until an invalid digit is found (or the end /// of the string), returning the number of processed digits /// and the parsed value until that point. /// /// Returns a `Result` containing either the parsed value /// and the number of processed digits, or an error containing /// any errors that occurred during parsing. /// /// * `bytes` - Slice containing a numeric string. fn from_lexical_partial(bytes: &[u8]) -> Result<(Self, usize)>; /// Checked parser for a string-to-number conversion. /// /// This method parses the entire string, returning an error if /// any invalid digits are found during parsing. /// /// Returns a `Result` containing either the parsed value, /// or an error containing any errors that occurred during parsing. /// /// Numeric overflow takes precedence over the presence of an invalid /// digit, and therefore may mask an invalid digit error. /// /// * `bytes` - Slice containing a numeric string. /// * `radix` - Radix for the number parsing. /// /// # Panics /// /// Panics if the radix is not in the range `[2, 36]`. #[cfg(feature = "radix")] fn from_lexical_radix(bytes: &[u8], radix: u8) -> Result<Self>; /// Checked parser for a string-to-number conversion. /// /// This method parses until an invalid digit is found (or the end /// of the string), returning the number of processed digits /// and the parsed value until that point. /// /// Returns a `Result` containing either the parsed value /// and the number of processed digits, or an error containing /// any errors that occurred during parsing. /// /// * `bytes` - Slice containing a numeric string. /// * `radix` - Radix for the number parsing. /// /// # Panics /// /// Panics if the radix is not in the range `[2, 36]`. #[cfg(feature = "radix")] fn from_lexical_partial_radix(bytes: &[u8], radix: u8) -> Result<(Self, usize)>; } // Implement FromLexical for numeric type. macro_rules! from_lexical { ($cb:expr, $t:ty) => ( impl FromLexical for $t { #[inline] fn from_lexical(bytes: &[u8]) -> Result<$t> { to_complete!($cb, bytes, 10) } #[inline] fn from_lexical_partial(bytes: &[u8]) -> Result<($t, usize)> { $cb(bytes, 10) } #[cfg(feature = "radix")] #[inline] fn from_lexical_radix(bytes: &[u8], radix: u8) -> Result<$t> { to_complete!($cb, bytes, radix.as_u32()) } #[cfg(feature = "radix")] #[inline] fn from_lexical_partial_radix(bytes: &[u8], radix: u8) -> Result<($t, usize)> { $cb(bytes, radix.as_u32()) } } ) } // FROM LEXICAL LOSSY /// Trait for floating-point types that can be parsed using lossy algorithms from bytes. pub trait FromLexicalLossy: FromLexical { /// Lossy, checked parser for a string-to-number conversion. /// /// This method parses the entire string, returning an error if /// any invalid digits are found during parsing. This parser is /// lossy, so numerical rounding may occur during parsing. /// /// Returns a `Result` containing either the parsed value, /// or an error containing any errors that occurred during parsing. /// /// * `bytes` - Slice containing a numeric string. fn from_lexical_lossy(bytes: &[u8]) -> Result<Self>; /// Lossy, checked parser for a string-to-number conversion. /// /// This method parses until an invalid digit is found (or the end /// of the string), returning the number of processed digits /// and the parsed value until that point. This parser is /// lossy, so numerical rounding may occur during parsing. /// /// Returns a `Result` containing either the parsed value /// and the number of processed digits, or an error containing /// any errors that occurred during parsing. /// /// * `bytes` - Slice containing a numeric string. fn from_lexical_partial_lossy(bytes: &[u8]) -> Result<(Self, usize)>; /// Lossy, checked parser for a string-to-number conversion. /// /// This method parses the entire string, returning an error if /// any invalid digits are found during parsing. This parser is /// lossy, so numerical rounding may occur during parsing. /// /// Returns a `Result` containing either the parsed value, /// or an error containing any errors that occurred during parsing. /// /// * `bytes` - Slice containing a numeric string. /// * `radix` - Radix for the number parsing. /// /// # Panics /// /// Panics if the radix is not in the range `[2, 36]`. #[cfg(feature = "radix")] fn from_lexical_lossy_radix(bytes: &[u8], radix: u8) -> Result<Self>; /// Lossy, checked parser for a string-to-number conversion. /// /// This method parses until an invalid digit is found (or the end /// of the string), returning the number of processed digits /// and the parsed value until that point. This parser is /// lossy, so numerical rounding may occur during parsing. /// /// Returns a `Result` containing either the parsed value /// and the number of processed digits, or an error containing /// any errors that occurred during parsing. /// /// * `bytes` - Slice containing a numeric string. /// * `radix` - Radix for the number parsing. /// /// # Panics /// /// Panics if the radix is not in the range `[2, 36]`. #[cfg(feature = "radix")] fn from_lexical_partial_lossy_radix(bytes: &[u8], radix: u8) -> Result<(Self, usize)>; } // Implement FromLexicalLossy for numeric type. macro_rules! from_lexical_lossy { ($cb:expr, $t:ty) => ( impl FromLexicalLossy for $t { #[inline] fn from_lexical_lossy(bytes: &[u8]) -> Result<$t> { to_complete!($cb, bytes, 10) } #[inline] fn from_lexical_partial_lossy(bytes: &[u8]) -> Result<($t, usize)> { $cb(bytes, 10) } #[cfg(feature = "radix")] #[inline] fn from_lexical_lossy_radix(bytes: &[u8], radix: u8) -> Result<$t> { to_complete!($cb, bytes, radix.as_u32()) } #[cfg(feature = "radix")] #[inline] fn from_lexical_partial_lossy_radix(bytes: &[u8], radix: u8) -> Result<($t, usize)> { $cb(bytes, radix.as_u32()) } } ) } // TO LEXICAL /// Trait for numerical types that can be serialized to bytes. /// /// To determine the number of bytes required to serialize a value to /// string, check the associated constants from a required trait: /// - [`FORMATTED_SIZE`] /// - [`FORMATTED_SIZE_DECIMAL`] /// /// [`FORMATTED_SIZE`]: trait.Number.html#associatedconstant.FORMATTED_SIZE /// [`FORMATTED_SIZE_DECIMAL`]: trait.Number.html#associatedconstant.FORMATTED_SIZE_DECIMAL pub trait ToLexical: Number { /// Serializer for a number-to-string conversion. /// /// Returns a subslice of the input buffer containing the written bytes, /// starting from the same address in memory as the input slice. /// /// * `value` - Number to serialize. /// * `bytes` - Slice containing a numeric string. /// /// # Panics /// /// Panics if the buffer is not of sufficient size. The caller /// must provide a slice of sufficient size. In order to ensure /// the function will not panic, ensure the buffer has at least /// [`FORMATTED_SIZE_DECIMAL`] elements. /// /// [`FORMATTED_SIZE_DECIMAL`]: trait.Number.html#associatedconstant.FORMATTED_SIZE_DECIMAL fn to_lexical<'a>(self, bytes: &'a mut [u8]) -> &'a mut [u8]; /// Serializer for a number-to-string conversion. /// /// Returns a subslice of the input buffer containing the written bytes, /// starting from the same address in memory as the input slice. /// /// * `value` - Number to serialize. /// * `radix` - Radix for number encoding. /// * `bytes` - Slice containing a numeric string. /// /// # Panics /// /// Panics if the radix is not in the range `[2, 36]`. /// /// Also panics if the buffer is not of sufficient size. The caller /// must provide a slice of sufficient size. In order to ensure /// the function will not panic, ensure the buffer has at least /// [`FORMATTED_SIZE`] elements. /// /// [`FORMATTED_SIZE`]: trait.Number.html#associatedconstant.FORMATTED_SIZE #[cfg(feature = "radix")] fn to_lexical_radix<'a>(self, radix: u8, bytes: &'a mut [u8]) -> &'a mut [u8]; } // Implement ToLexical for numeric type. macro_rules! to_lexical { ($cb:expr, $t:ty) => ( impl ToLexical for $t { #[inline] fn to_lexical<'a>(self, bytes: &'a mut [u8]) -> &'a mut [u8] { assert_buffer!(10, bytes, $t); let len = $cb(self, 10, bytes); &mut index_mut!(bytes[..len]) } #[cfg(feature = "radix")] #[inline] fn to_lexical_radix<'a>(self, radix: u8, bytes: &'a mut [u8]) -> &'a mut [u8] { assert_radix!(radix); assert_buffer!(radix, bytes, $t); let len = $cb(self, radix.as_u32(), bytes); &mut index_mut!(bytes[..len]) } } ) }