Creating my own U8 type

[jymchng]

Following the tutorial from the docs on creating a new boolean using MLIR, I tried to create my own new U8 type.

Yet, it is difficult to do so because the constructor (__init__) will need to take Int as a parameter and I'm not too sure how to check for the value passed into the constructor such that it doesn't overflow etc.

struct U8:
   var value: __mlir_type.ui8

   fn __init__(inout self, value: Int):
      self.value = value


fn main():
   let a = U8(__mlir_attr.`55`)

In the MLIR docs for index.cmp in the index dialect, the cmp operation is as follows:

operation ::= `index.cmp` `` $pred `(` $lhs `,` $rhs `)` attr-dict

In the Mojo docs, the 'conversion' to Mojo's syntax is as follows:

fn __eq__(self, rhs: OurBool) -> Self:
    let lhsIndex = __mlir_op.`index.casts`[_type : __mlir_type.index](
        self.value
    )
    let rhsIndex = __mlir_op.`index.casts`[_type : __mlir_type.index](
        rhs.value
    )
    return Self(
        __mlir_op.`index.cmp`[
            pred : __mlir_attr.`#index<cmp_predicate eq>`
        ](lhsIndex, rhsIndex)
    )

How does

`index.cmp` `` $pred `(` $lhs `,` $rhs `)` attr-dict`

get converted to

__mlir_attr.`#index<cmp_predicate eq>`

[jymchng]

How is Int represented in MLIR?

[alfie-nsugh]

I think it has to do with this:
https://mlir.llvm.org/docs/LangRef/#dialect-attribute-values