forst-lang / forst / 24314986808

76%

Build Type

push

github

Committed by haveyaseen

Commit Message

fix(typechecker): narrow Result ensure blocks to the failure branch

`ensure x is Ok() { ... }` / `Err()` now refines the subject inside the block to
the payload type that matches the generated `if !(ok)` branch (F after Ok, S
after Err), then applies successor narrowing for the passing path. Adds
`Ok()`/`Err()` method typing and completion on built-in `Result(S, F)`.

Example:

```forst
x := f()
ensure x is Ok() {
  println(x) // failure payload while Ok() is false
}
println(x.Ok())
```

fix(transformer): map narrowed Result locals to split Go names

When a Result binding is narrowed out of `Result` form, plain references and
`x.Ok()`/`x.Err()` calls target the correct success/error Go identifiers;
`println` expands only while the binding is still a full Result. Restores the
ensure block scope before lowering the failure body so narrowing matches the
typechecker.

feat(lsp): qualify guard hovers using the inferred subject type

Guard identifiers after `is` use `InferredTypesForVariableIdentifier` so hovers
show titles like `Int.GreaterThan` instead of only the bare guard name.

Example:

```forst
ensure n is GreaterThan(0)
```

fix(printer): format `ensure` error alternatives and nested statement indentation

Prints `or` clauses on their own indented line; avoids double-indenting
statements that already embed nested block layout.

feat(vscode-forst): highlight nominal `error Name` and core builtin types

Adds a pattern for `error Name { ... }`, treats `error` as a declaration
keyword, classifies `Error`/`Result`/`Tuple`, and highlights `true`/`false`.

test: extend Result narrowing, LSP hover, and typechecker coverage

Updates `examples/in/ensure.ft` and golden `ensure.go` for the Result-based flow.

Coverage Stats

139 of 192 new or added lines in 10 files covered. (72.4%)

8 existing lines in 2 files now uncovered.

16792 of 26657 relevant lines covered (62.99%)

20.45 hits per line