Intermediate representation

Helios scripts aren't compiled directly to UPLC. Rather they are compiled into an Intermediate Representation (IR). This section describes the components of the IR and how the simplification process works. This can be useful information for auditors of the Helios code-base.

The Helios IR is a typeless variant of Helios, where high-level syntactic constructs have been replaced by low-level equivalents (represented a class hierarchy with IRExpr as a base class):

IRNameExpr
IRLiteralExpr
IRConstExpr
IRFuncExpr
IRCallExpr
- IRCoreCallExpr
- IRUserCallExpr
  - IRAnonCallExpr
    - IRFuncDefExpr
  - IRNestedAnonCallExpr
IRErrorCallExpr

The remaining part of this page describes the IR syntax.

`IRNameExpr`

Any word matching of the regular expression [_a-zA-Z][_a-zA-Z0-9]*, except the following keywords: const, error, true, false.

`IRLiteralExpr`

true or false for a literal Bool
##[0-9a-f]* for literal Data
#[0-9a-f]* for a literal ByteArray
".*" for a literal String
[0-9]+ for a literal Int

`IRConstExpr`

Emitted by Helios const statements.

const(<expr>)

`IRFuncExpr`

(<arg-name>, <arg-name>, ...) -> {
    <body-expr>
}

`IRCallExpr`

`IRCoreCallExpr`

__core__<builtin-name>(<arg-expr>, <arg-expr>, ...)

`IRUserCallExpr`

<expr>(<arg-expr>, <arg-expr>, ...)

`IRAnonCallExpr`

(<arg-name>, <arg-name>, ...) -> {
    <body-expr>
}(<arg-expr>, <arg-expr>, ...)

`IRNestedAnonCallExpr`

(<arg-name>, <arg-name>, ...) -> {
    <body-expr>
}(<arg-expr>, <arg-expr>, ...)(<call-arg-expr>, ...)

`IRFuncDefExpr`

(<fn-name>) -> {
    <rest-expr>
}(
    (<arg-name>, <arg-name>, ...) -> {
        <body-expr>
    }
)

`IRErrorCallExpr`

error(".*")