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Description
First off, great framework! As someone who hasn't worked a lot with data interchange formats, I was surprised that the first formats I ran into didn't have both strict support for non-nullable types and ADTs.
Description
I'm trying to define a recursive type, but it looks like it's not supported.
[Error] Cycle detected: types.Foo → types.FooOrBar → types.Foo.
Schema:
struct Foo {
a: String = 0
b: FooOrBar = 1
}
struct Bar {
a: String = 0
}
choice FooOrBar {
foo: Foo = 0
bar: Bar = 1
}
I was hoping that making the field optional, or replacing a directly recursive field with a choice that allows the recursion to end would allow the codegen to succeed, but it looks like recursive types in any form will trigger the error.
Are there any thoughts / plans on supporting this? I could imagine having some ability to limit the depth, like Rust's ![recursion_limit = "512"].
This would have to result in a Box on the rust side: Playground
Alternatives considered
The actual situation I'm working with is in modeling a type-check diagnostic result from typescript's compiler api. As a workaround, I've added another type which omits the recursive field, and will have to flatten out the data into a plain array
Typical
struct Diagnostic {
source: String = 0
information: [DiagnosticInformation] = 1
}
struct DiagnosticInformation {
category: DiagnosticCategory = 0
code: S64 = 1
optional file: File = 2
optional start: U64 = 3
optional length: U64 = 4
message: DiagnosticMessage = 5
}
choice DiagnosticCategory {
warning = 0
error = 1
suggestion = 2
message = 3
}
choice DiagnosticMessage {
text: String = 0
chain: DiagnosticMessageChain = 1
}
struct DiagnosticMessageChain {
text: String = 0
category: DiagnosticCategory = 1
code: S64 = 2
# Recursive in typescript's compiler API definition. Flatten out before sending
optional next: [DiagnosticMessageChainFlat] = 3
}
struct DiagnosticMessageChainFlat {
text: String = 0
category: DiagnosticCategory = 1
code: S64 = 2
}
Taken from typescript 4.7.4 source code
export interface Diagnostic extends DiagnosticRelatedInformation { /** May store more in future. For now, this will simply be `true` to indicate when a diagnostic is an unused-identifier diagnostic. */ reportsUnnecessary?: {}; reportsDeprecated?: {}; source?: string; relatedInformation?: DiagnosticRelatedInformation[]; } export interface DiagnosticRelatedInformation { category: DiagnosticCategory; code: number; file: SourceFile | undefined; start: number | undefined; length: number | undefined; messageText: string | DiagnosticMessageChain; } /** * A linked list of formatted diagnostic messages to be used as part of a multiline message. * It is built from the bottom up, leaving the head to be the "main" diagnostic. * While it seems that DiagnosticMessageChain is structurally similar to DiagnosticMessage, * the difference is that messages are all preformatted in DMC. */ export interface DiagnosticMessageChain { messageText: string; category: DiagnosticCategory; code: number; next?: DiagnosticMessageChain[]; }