First try at replacing partials lines

[killercup]

Concerns #1

[killercup]

Currently it screws up the first example…

-                mem::transmute::<*mut c_void, &mut Box<FnMut(&Button)>>(data)(&button)
+                &mut *(data as *mut Box<for<'r> std::ops::FnMut(&'r controls::Button)>)Button)>)&button)

But I have not yet investigated why that is.

This is the span from the clippy.json file:

{
    "file_name": "src/controls.rs",
    "byte_start": 7710,
    "byte_end": 7771,
    "line_start": 245,
    "line_end": 245,
    "column_start": 17,
    "column_end": 78,
    "is_primary": true,
    "text": [
        {
            "text": "                mem::transmute::<*mut c_void, &mut Box<FnMut(&Button)>>(data)(&button)",
            "highlight_start": 17,
            "highlight_end": 78
        }
    ],
    "label": null,
    "suggested_replacement": "&mut *(data as *mut Box<for<'r> std::ops::FnMut(&'r controls::Button)>)",
    "expansion": null
}

[killercup]

Oh, actually, I'm stupid. This might be clippy's fault: Column 78 is just before (&button) (cutting off the ( is my fault, though!)

cc @mcarton

[mcarton]

Yes, clippy forgets to add parenthesis: foo(bar)(baz) is transformed into &mut *(…)(baz) while it should be (&mut *(…))(baz). This will be fixed. https://github.com/Manishearth/rust-clippy/pull/1060 correctly handles parenthesis inside the suggestions, and I'm planning to correctly handle parenthesis around them (and also whether ; is needed) in another PR.