Auto merge of #21187 - oli-obk:feature/hint_struct_field_access, r=alexcrichton

rebase and fix of #19267
This commit is contained in:
bors 2015-01-22 12:09:02 +00:00
commit b7930d93d9
4 changed files with 112 additions and 1 deletions

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@ -1,4 +1,4 @@
// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
// Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
@ -108,6 +108,7 @@ use lint;
use util::common::{block_query, indenter, loop_query};
use util::ppaux::{self, Repr};
use util::nodemap::{DefIdMap, FnvHashMap, NodeMap};
use util::lev_distance::lev_distance;
use std::cell::{Cell, Ref, RefCell};
use std::mem::replace;
@ -3071,11 +3072,43 @@ fn check_expr_with_unifier<'a, 'tcx, F>(fcx: &FnCtxt<'a, 'tcx>,
actual)
},
expr_t, None);
if let Some(t) = ty::ty_to_def_id(expr_t) {
suggest_field_names(t, field, tcx, vec![]);
}
}
fcx.write_error(expr.id);
}
// displays hints about the closest matches in field names
fn suggest_field_names<'tcx>(id : DefId,
field : &ast::SpannedIdent,
tcx : &ty::ctxt<'tcx>,
skip : Vec<&str>) {
let ident = token::get_ident(field.node);
let name = ident.get();
// only find fits with at least one matching letter
let mut best_dist = name.len();
let mut best = None;
let fields = ty::lookup_struct_fields(tcx, id);
for elem in fields.iter() {
let n = elem.name.as_str();
// ignore already set fields
if skip.iter().any(|&x| x == n) {
continue;
}
let dist = lev_distance(n, name);
if dist < best_dist {
best = Some(n);
best_dist = dist;
}
}
if let Some(n) = best {
tcx.sess.span_help(field.span,
format!("did you mean `{}`?", n).as_slice());
}
}
// Check tuple index expressions
fn check_tup_field(fcx: &FnCtxt,
expr: &ast::Expr,
@ -3183,6 +3216,13 @@ fn check_expr_with_unifier<'a, 'tcx, F>(fcx: &FnCtxt<'a, 'tcx>,
},
struct_ty,
None);
// prevent all specified fields from being suggested
let skip_fields = ast_fields.iter().map(|ref x| x.ident.node.name.as_str());
let actual_id = match enum_id_opt {
Some(_) => class_id,
None => ty::ty_to_def_id(struct_ty).unwrap()
};
suggest_field_names(actual_id, &field.ident, tcx, skip_fields.collect());
error_happened = true;
}
Some((_, true)) => {

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@ -0,0 +1,24 @@
// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
struct A {
foo : i32,
car : i32,
barr : i32
}
fn main() {
let a = A {
foo : 5,
bar : 42,//~ ERROR structure `A` has no field named `bar`
//~^ HELP did you mean `barr`?
car : 9,
};
}

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@ -0,0 +1,23 @@
// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
struct A {
foo : i32,
car : i32,
barr : i32
}
fn main() {
let a = A {
foo : 5,
bar : 42,//~ ERROR structure `A` has no field named `bar`
//~^ HELP did you mean `car`?
};
}

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@ -0,0 +1,24 @@
// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
struct BuildData {
foo: isize,
bar: f32
}
fn main() {
let foo = BuildData {
foo: 0,
bar: 0.5,
};
let x = foo.baa;//~ ERROR attempted access of field `baa` on type `BuildData`
//~^ HELP did you mean `bar`?
println!("{}", x);
}