Draft: PoC: use tuple constructors
Motivation and Context
We introduce variant types with a union-like syntax in JsLIGO:
type t = | ["Foo", int, string] | ["Bar"] | ["C", option<int>];
However, constructor application is used using a different syntax: Foo(42, "hello")
This is a proof of concept MR trying a more regular syntax for constructor application by modifying mostly the typer.
Description
In this MR we try some small local changes on the typer to allow writing constructor application as ["Foo", 42, "hello"]
.
After those changes, we can currently type:
type t = | ["Foo", int, string] | ["Bar"] | ["C", option<int>];
const tx : t = ["Foo", 42, "bar"];
const y = ["Bar"]; // t
const l = ["x", "y"]; // [string, string]
const i : [string, option<int>] = ["C", ["Some", 42]];
const j = (y) => match (y) {
when(["Foo", i, _s]): i + 1;
when(["Bar"]): -1;
when(["C", ["Some", n]]): n;
when(["C", ["None"]]): -2;
}; // (y : t) => int
const h = ["Some", ["C", ["None"]]]; // t
Component
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compiler -
website -
webide -
vscode-plugin -
debugger
Types of changes
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Bug fix (non-breaking change which fixes an issue) -
New feature (non-breaking change which adds functionality) -
Breaking change (fix or feature that would cause existing functionality to not work as expected) -
Performance improvement (non-breaking change that improves performance) -
None (change with no changelog)
Changelog
Checklist:
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If a new syntax has been introduced, put a message on slack ligo-lsp -
Changes follow the existing coding style (use dune @fmt
to check). -
Tests for the changes have been added (for bug fixes / feature). -
Documentation has been updated. -
Changelog description has been added (if appropriate). -
Start titles under ## Changelog
section with #### (if appropriate). -
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Examples in changed behaviour have been added to the changelog (for breaking change / feature).