facet-format 0.43.0

Core Serializer/Deserializer traits for facet's next-generation format architecture with JIT compilation support
Documentation 
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extern crate alloc;

use std::borrow::Cow;

use facet_core::ScalarType;
use facet_reflect::{Partial, ReflectError};

use crate::{DeserializeError, FormatDeserializer, FormatParser, ScalarValue};

impl<'input, const BORROW: bool, P> FormatDeserializer<'input, BORROW, P>
where
    P: FormatParser<'input>,
{
    pub(crate) fn set_scalar(
        &mut self,
        mut wip: Partial<'input, BORROW>,
        scalar: ScalarValue<'input>,
    ) -> Result<Partial<'input, BORROW>, DeserializeError<P::Error>> {
        let shape = wip.shape();
        let scalar_type = shape.scalar_type();
        // Capture the span for error reporting - this is where the scalar value was parsed
        let span = self.last_span;
        let reflect_err = |e: ReflectError| DeserializeError::Reflect {
            error: e,
            span,
            path: None,
        };

        match scalar {
            ScalarValue::Null => {
                wip = wip.set_default().map_err(&reflect_err)?;
            }
            ScalarValue::Bool(b) => {
                wip = wip.set(b).map_err(&reflect_err)?;
            }
            ScalarValue::Char(c) => {
                wip = wip.set(c).map_err(&reflect_err)?;
            }
            ScalarValue::I64(n) => {
                match scalar_type {
                    // Handle signed types
                    Some(ScalarType::I8) => wip = wip.set(n as i8).map_err(&reflect_err)?,
                    Some(ScalarType::I16) => wip = wip.set(n as i16).map_err(&reflect_err)?,
                    Some(ScalarType::I32) => wip = wip.set(n as i32).map_err(&reflect_err)?,
                    Some(ScalarType::I64) => wip = wip.set(n).map_err(&reflect_err)?,
                    Some(ScalarType::I128) => wip = wip.set(n as i128).map_err(&reflect_err)?,
                    Some(ScalarType::ISize) => wip = wip.set(n as isize).map_err(&reflect_err)?,
                    // Handle unsigned types (I64 can fit in unsigned if non-negative)
                    Some(ScalarType::U8) => wip = wip.set(n as u8).map_err(&reflect_err)?,
                    Some(ScalarType::U16) => wip = wip.set(n as u16).map_err(&reflect_err)?,
                    Some(ScalarType::U32) => wip = wip.set(n as u32).map_err(&reflect_err)?,
                    Some(ScalarType::U64) => wip = wip.set(n as u64).map_err(&reflect_err)?,
                    Some(ScalarType::U128) => wip = wip.set(n as u128).map_err(&reflect_err)?,
                    Some(ScalarType::USize) => wip = wip.set(n as usize).map_err(&reflect_err)?,
                    // Handle floats
                    Some(ScalarType::F32) => wip = wip.set(n as f32).map_err(&reflect_err)?,
                    Some(ScalarType::F64) => wip = wip.set(n as f64).map_err(&reflect_err)?,
                    // Handle String - stringify the number
                    Some(ScalarType::String) => {
                        wip = wip
                            .set(alloc::string::ToString::to_string(&n))
                            .map_err(&reflect_err)?
                    }
                    _ => wip = wip.set(n).map_err(&reflect_err)?,
                }
            }
            ScalarValue::U64(n) => {
                match scalar_type {
                    // Handle unsigned types
                    Some(ScalarType::U8) => wip = wip.set(n as u8).map_err(&reflect_err)?,
                    Some(ScalarType::U16) => wip = wip.set(n as u16).map_err(&reflect_err)?,
                    Some(ScalarType::U32) => wip = wip.set(n as u32).map_err(&reflect_err)?,
                    Some(ScalarType::U64) => wip = wip.set(n).map_err(&reflect_err)?,
                    Some(ScalarType::U128) => wip = wip.set(n as u128).map_err(&reflect_err)?,
                    Some(ScalarType::USize) => wip = wip.set(n as usize).map_err(&reflect_err)?,
                    // Handle signed types (U64 can fit in signed if small enough)
                    Some(ScalarType::I8) => wip = wip.set(n as i8).map_err(&reflect_err)?,
                    Some(ScalarType::I16) => wip = wip.set(n as i16).map_err(&reflect_err)?,
                    Some(ScalarType::I32) => wip = wip.set(n as i32).map_err(&reflect_err)?,
                    Some(ScalarType::I64) => wip = wip.set(n as i64).map_err(&reflect_err)?,
                    Some(ScalarType::I128) => wip = wip.set(n as i128).map_err(&reflect_err)?,
                    Some(ScalarType::ISize) => wip = wip.set(n as isize).map_err(&reflect_err)?,
                    // Handle floats
                    Some(ScalarType::F32) => wip = wip.set(n as f32).map_err(&reflect_err)?,
                    Some(ScalarType::F64) => wip = wip.set(n as f64).map_err(&reflect_err)?,
                    // Handle String - stringify the number
                    Some(ScalarType::String) => {
                        wip = wip
                            .set(alloc::string::ToString::to_string(&n))
                            .map_err(&reflect_err)?
                    }
                    _ => wip = wip.set(n).map_err(&reflect_err)?,
                }
            }
            ScalarValue::U128(n) => {
                match scalar_type {
                    Some(ScalarType::U128) => wip = wip.set(n).map_err(&reflect_err)?,
                    Some(ScalarType::I128) => wip = wip.set(n as i128).map_err(&reflect_err)?,
                    // For smaller types, truncate (caller should have used correct hint)
                    _ => wip = wip.set(n as u64).map_err(&reflect_err)?,
                }
            }
            ScalarValue::I128(n) => {
                match scalar_type {
                    Some(ScalarType::I128) => wip = wip.set(n).map_err(&reflect_err)?,
                    Some(ScalarType::U128) => wip = wip.set(n as u128).map_err(&reflect_err)?,
                    // For smaller types, truncate (caller should have used correct hint)
                    _ => wip = wip.set(n as i64).map_err(&reflect_err)?,
                }
            }
            ScalarValue::F64(n) => {
                match scalar_type {
                    Some(ScalarType::F32) => wip = wip.set(n as f32).map_err(&reflect_err)?,
                    Some(ScalarType::F64) => wip = wip.set(n).map_err(&reflect_err)?,
                    _ if shape.vtable.has_try_from() && shape.inner.is_some() => {
                        // For opaque types with try_from (like NotNan, OrderedFloat), use
                        // begin_inner() + set + end() to trigger conversion
                        let inner_shape = shape.inner.unwrap();
                        wip = wip.begin_inner().map_err(&reflect_err)?;
                        if inner_shape.is_type::<f32>() {
                            wip = wip.set(n as f32).map_err(&reflect_err)?;
                        } else {
                            wip = wip.set(n).map_err(&reflect_err)?;
                        }
                        wip = wip.end().map_err(&reflect_err)?;
                    }
                    _ if shape.vtable.has_parse() => {
                        // For types that support parsing (like Decimal), convert to string
                        // and use parse_from_str to preserve their parsing semantics
                        wip = wip
                            .parse_from_str(&alloc::string::ToString::to_string(&n))
                            .map_err(&reflect_err)?;
                    }
                    _ => wip = wip.set(n).map_err(&reflect_err)?,
                }
            }
            ScalarValue::Str(s) => {
                // Try parse_from_str first if the type supports it
                if shape.vtable.has_parse() {
                    wip = wip.parse_from_str(s.as_ref()).map_err(&reflect_err)?;
                } else {
                    wip = self.set_string_value(wip, s)?;
                }
            }
            ScalarValue::Bytes(b) => {
                // First try parse_from_bytes if the type supports it (e.g., UUID from 16 bytes)
                if shape.vtable.has_parse_bytes() {
                    wip = wip.parse_from_bytes(b.as_ref()).map_err(&reflect_err)?;
                } else {
                    // Fall back to setting as Vec<u8>
                    wip = wip.set(b.into_owned()).map_err(&reflect_err)?;
                }
            }
            ScalarValue::Unit => {
                // Unit value - set to default/unit value
                wip = wip.set_default().map_err(&reflect_err)?;
            }
        }

        Ok(wip)
    }

    /// Set a string value, handling `&str`, `Cow<str>`, and `String` appropriately.
    pub(crate) fn set_string_value(
        &mut self,
        wip: Partial<'input, BORROW>,
        s: Cow<'input, str>,
    ) -> Result<Partial<'input, BORROW>, DeserializeError<P::Error>> {
        facet_dessert::set_string_value(wip, s, self.last_span).map_err(|e| match e {
            facet_dessert::DessertError::Reflect { error, span } => DeserializeError::Reflect {
                error,
                span,
                path: None,
            },
            facet_dessert::DessertError::CannotBorrow { message } => {
                DeserializeError::CannotBorrow {
                    message: message.into_owned(),
                }
            }
        })
    }

    /// Set a bytes value with proper handling for borrowed vs owned data.
    ///
    /// This handles `&[u8]`, `Cow<[u8]>`, and `Vec<u8>` appropriately based on
    /// whether borrowing is enabled and whether the data is borrowed or owned.
    pub(crate) fn set_bytes_value(
        &mut self,
        wip: Partial<'input, BORROW>,
        b: Cow<'input, [u8]>,
    ) -> Result<Partial<'input, BORROW>, DeserializeError<P::Error>> {
        facet_dessert::set_bytes_value(wip, b, self.last_span).map_err(|e| match e {
            facet_dessert::DessertError::Reflect { error, span } => DeserializeError::Reflect {
                error,
                span,
                path: None,
            },
            facet_dessert::DessertError::CannotBorrow { message } => {
                DeserializeError::CannotBorrow {
                    message: message.into_owned(),
                }
            }
        })
    }
}