From 774f36b5d80cdde405be27729b3700abbecf910b Mon Sep 17 00:00:00 2001 From: Jakub Wieczorek Date: Mon, 2 Jun 2014 20:49:44 +0200 Subject: [PATCH] Remove further code duplication --- src/librustc/middle/check_match.rs | 193 +++++++++-------------------- 1 file changed, 56 insertions(+), 137 deletions(-) diff --git a/src/librustc/middle/check_match.rs b/src/librustc/middle/check_match.rs index bcc132941973..26bc845a15aa 100644 --- a/src/librustc/middle/check_match.rs +++ b/src/librustc/middle/check_match.rs @@ -409,24 +409,12 @@ fn missing_ctor(cx: &MatchCheckCtxt, _ => check_matrix_for_wild(cx, m), }, ty::ty_enum(eid, _) => { - let mut found = Vec::new(); - for r in m.iter() { - let r = pat_ctor_id(cx, *r.get(0)); - for id in r.move_iter() { - if !found.contains(&id) { - found.push(id); - } - } - } + let pat_ctors: Vec = m + .iter() + .filter_map(|r| pat_ctor_id(cx, *r.get(0))) + .collect(); let variants = ty::enum_variants(cx.tcx, eid); - if found.len() != (*variants).len() { - for v in (*variants).iter() { - if !found.iter().any(|x| x == &(variant(v.id))) { - return Some(variant(v.id)); - } - } - fail!(); - } else { None } + variants.iter().map(|v| variant(v.id)).find(|c| !pat_ctors.contains(c)) } ty::ty_nil => None, ty::ty_bool => { @@ -567,6 +555,21 @@ fn wild_multi() -> @Pat { @Pat {id: 0, node: PatWildMulti, span: DUMMY_SP} } +fn range_covered_by_constructor(ctor_id: &ctor, from: &const_val, to: &const_val) -> Option { + let (c_from, c_to) = match *ctor_id { + val(ref value) => (value, value), + range(ref from, ref to) => (from, to), + single => return Some(true), + _ => unreachable!() + }; + let cmp_from = compare_const_vals(c_from, from); + let cmp_to = compare_const_vals(c_to, to); + match (cmp_from, cmp_to) { + (Some(val1), Some(val2)) => Some(val1 >= 0 && val2 <= 0), + _ => None + } +} + fn specialize(cx: &MatchCheckCtxt, r: &[@Pat], ctor_id: &ctor, @@ -592,41 +595,15 @@ fn specialize(cx: &MatchCheckCtxt, } } Some(DefStatic(did, _)) => { - let const_expr = - lookup_const_by_id(cx.tcx, did).unwrap(); + let const_expr = lookup_const_by_id(cx.tcx, did).unwrap(); let e_v = eval_const_expr(cx.tcx, const_expr); - let match_ = match *ctor_id { - val(ref v) => { - match compare_const_vals(&e_v, v) { - Some(val1) => (val1 == 0), - None => { - cx.tcx.sess.span_err(*pat_span, - "mismatched types between arms"); - false - } - } - }, - range(ref c_lo, ref c_hi) => { - let m1 = compare_const_vals(c_lo, &e_v); - let m2 = compare_const_vals(c_hi, &e_v); - match (m1, m2) { - (Some(val1), Some(val2)) => { - (val1 >= 0 && val2 <= 0) - } - _ => { - cx.tcx.sess.span_err(*pat_span, - "mismatched types between ranges"); - false - } - } - } - single => true, - _ => fail!("type error") - }; - if match_ { - Some(vec!()) - } else { - None + match range_covered_by_constructor(ctor_id, &e_v, &e_v) { + Some(true) => Some(vec!()), + Some(false) => None, + None => { + cx.tcx.sess.span_err(*pat_span, "mismatched types between arms"); + None + } } } _ => { @@ -638,38 +615,15 @@ fn specialize(cx: &MatchCheckCtxt, let def = cx.tcx.def_map.borrow().get_copy(pat_id); match def { DefStatic(did, _) => { - let const_expr = - lookup_const_by_id(cx.tcx, did).unwrap(); + let const_expr = lookup_const_by_id(cx.tcx, did).unwrap(); let e_v = eval_const_expr(cx.tcx, const_expr); - let match_ = match *ctor_id { - val(ref v) => - match compare_const_vals(&e_v, v) { - Some(val1) => (val1 == 0), - None => { - cx.tcx.sess.span_err(*pat_span, - "mismatched types between arms"); - false - } - }, - range(ref c_lo, ref c_hi) => { - let m1 = compare_const_vals(c_lo, &e_v); - let m2 = compare_const_vals(c_hi, &e_v); - match (m1, m2) { - (Some(val1), Some(val2)) => (val1 >= 0 && val2 <= 0), - _ => { - cx.tcx.sess.span_err(*pat_span, - "mismatched types between ranges"); - false - } - } - } - single => true, - _ => fail!("type error") - }; - if match_ { - Some(vec!()) - } else { - None + match range_covered_by_constructor(ctor_id, &e_v, &e_v) { + Some(true) => Some(vec!()), + Some(false) => None, + None => { + cx.tcx.sess.span_err(*pat_span, "mismatched types between arms"); + None + } } } DefVariant(_, id, _) if variant(id) != *ctor_id => None, @@ -720,68 +674,33 @@ fn specialize(cx: &MatchCheckCtxt, } &PatTup(ref args) => { - Some(args.iter().map(|x| *x).collect()) + Some(args.clone()) } &PatBox(ref inner) | &PatRegion(ref inner) => { Some(vec!(inner.clone())) } &PatLit(ref expr) => { - let e_v = eval_const_expr(cx.tcx, *expr); - let match_ = match *ctor_id { - val(ref v) => { - match compare_const_vals(&e_v, v) { - Some(val1) => val1 == 0, - None => { - cx.tcx.sess.span_err(*pat_span, - "mismatched types between arms"); - false - } - } - }, - range(ref c_lo, ref c_hi) => { - let m1 = compare_const_vals(c_lo, &e_v); - let m2 = compare_const_vals(c_hi, &e_v); - match (m1, m2) { - (Some(val1), Some(val2)) => (val1 >= 0 && val2 <= 0), - _ => { - cx.tcx.sess.span_err(*pat_span, - "mismatched types between ranges"); - false - } - } - } - single => true, - _ => fail!("type error") - }; - if match_ { - Some(vec!()) - } else { + let expr_value = eval_const_expr(cx.tcx, *expr); + match range_covered_by_constructor(ctor_id, &expr_value, &expr_value) { + Some(true) => Some(vec!()), + Some(false) => None, + None => { + cx.tcx.sess.span_err(*pat_span, "mismatched types between arms"); None - } + } + } } - &PatRange(lo, hi) => { - let (c_lo, c_hi) = match *ctor_id { - val(ref v) => (v, v), - range(ref lo, ref hi) => (lo, hi), - single => return Some(vec!()), - _ => fail!("type error") - }; - let v_lo = eval_const_expr(cx.tcx, lo); - let v_hi = eval_const_expr(cx.tcx, hi); - - let m1 = compare_const_vals(c_lo, &v_lo); - let m2 = compare_const_vals(c_hi, &v_hi); - match (m1, m2) { - (Some(val1), Some(val2)) if val1 >= 0 && val2 <= 0 => { - Some(vec!()) - }, - (Some(_), Some(_)) => None, - _ => { - cx.tcx.sess.span_err(*pat_span, - "mismatched types between ranges"); - None - } - } + &PatRange(ref from, ref to) => { + let from_value = eval_const_expr(cx.tcx, *from); + let to_value = eval_const_expr(cx.tcx, *to); + match range_covered_by_constructor(ctor_id, &from_value, &to_value) { + Some(true) => Some(vec!()), + Some(false) => None, + None => { + cx.tcx.sess.span_err(*pat_span, "mismatched types between arms"); + None + } + } } &PatVec(ref before, ref slice, ref after) => { match *ctor_id {