bun_sql 0.1.0

A Rust-native programmable browser runtime built on Servo and SpiderMonkey
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use core::marker::PhantomData;

use crate::postgres::any_postgres_error::AnyPostgresError;
use crate::postgres::protocol::new_writer::{NewWriter, WriterContext};

// Zig: `fn WriteWrap(comptime Container: type, comptime writeFn: anytype) type { return struct { ... } }`
//
// `writeFn` is a comptime *value* (a function) bound at type-construction time, not passed
// per-call. Stable Rust cannot take a fn as a const generic, so we model it as a ZST type
// parameter `F: WriteFn<Container>` — callers supply a unit struct that impls the trait.
// This keeps `write(this, context)` 2-arg, matching the Zig signature for side-by-side diff.
// TODO(refactor): check call sites and consider flattening this to a trait directly on
// `Container` (a provided `write` method) instead of a zero-sized generic struct.
pub trait WriteFn<Container> {
    fn call<Ctx: WriterContext>(
        this: &mut Container,
        writer: NewWriter<Ctx>,
    ) -> Result<(), AnyPostgresError>;
}

pub struct WriteWrap<Container, F>(PhantomData<(Container, F)>);

impl<Container, F: WriteFn<Container>> WriteWrap<Container, F> {
    pub fn write<Ctx: WriterContext>(
        this: &mut Container,
        context: Ctx,
    ) -> Result<(), AnyPostgresError> {
        // Zig passed `Context` (the type) as an explicit arg; in Rust the generic `<Ctx>`
        // IS that arg (see PORTING.md §Comptime reflection — `@TypeOf` is dropped).
        F::call(this, NewWriter { wrapped: context })?;
        Ok(())
    }
}

// ported from: src/sql/postgres/protocol/WriteWrap.zig