E0007 — Type mismatch

An expression’s type doesn’t match what the context expects.

---

What triggers it

The typechecker walks each expression and compares its type against the declared or inferred requirement at the use site. Mismatches — let x: int = "hi";, passing a Bool where a function wants an Int, storing a Float in an Int local — all surface here.

Minimal example

fn main() {
    let x: int = "hi";
    return 0;
}

Output:

scratch.rs:2:18: error[E0007]: type mismatch: expected `int`, got `String`
   let x: int = "hi";
                ^^^^

Fix

Change one side to match the other. If you meant to parse / convert, call the matching builtin (to_int, to_float, etc.).

fn main() {
    let x: int = 42;
    return 0;
}

Source

Emitted from the typechecker in resilient/src/typechecker.rs.