Article: NuttX RTOS for PinePhone: Feature Phone UI in LVGL, Zig and WebAssembly

[WhiteHexagon]

Code:

pub const I2S_PCM0 = IRQ(45);
pub const I2S_PCM1 = IRQ(46);
pub const I2S_PCM2 = IRQ(47);
pub const PG_EINT = IRQ(49);
pub const TIMER0 = IRQ(50);
pub const TIMER1 = IRQ(51);

fn IRQ(comptime irq: u8) type {
    const cache = struct {
        var lookup: [IRQ_LIMIT]*const fn () void = undefined;

        pub export fn zigInterruptHandler(id: c_int) void {
            const handler = lookup[@intCast(u8, id)];
            handler();
            debug.green(true);
        }
    };
    return struct {
        const irqNo: u8 = irq;
        var enabled: bool = false;

        pub fn enable(handler: *const fn () void) void {
            if (!enabled) {
                c.enableIRQ(irqNo);
                cache.lookup[irqNo] = handler;
                enabled = true;
            }
        }
    };
}

Oh and the code if you are interested.  It works if I move the exported fn and lookup table up to the file level, but since that is also just a 'struct' in Zig, I thought this might work.