---

yaml
---
r: 39599
b: refs/heads/incoming
c: 56227c4
h: refs/heads/master
i:
  39597: 594486d
  39595: cfe1154
  39591: fe5facd
  39583: 71216d2
v: v3

Author: catamorphism

[refs]

@@ -6,7 +6,7 @@ refs/heads/try: 3d5418789064fdb463e872a4e651af1c628a3650
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b
 refs/heads/try2: a810c03263670238bccd64cabb12a23a46e3a278
-refs/heads/incoming: 2cf2d6aa923a3d05f5bc9caae4cac757e1e27b57
+refs/heads/incoming: 56227c42b387d0463f8c72f1a37d5a3b61197912
 refs/heads/dist-snap: 22efa39382d41b084fde1719df7ae8ce5697d8c9
 refs/tags/release-0.2: c870d2dffb391e14efb05aa27898f1f6333a9596
 refs/tags/release-0.3: b5f0d0f648d9a6153664837026ba1be43d3e2503

branches/incoming/doc/rust.md

@@ -1107,6 +1107,19 @@ let mut a: Animal = Dog;
 a = Cat;
 ~~~~
 
+Enumeration constructors can have either named or unnamed fields:
+~~~~
+enum Animal {
+    Dog (~str, float),
+    Cat { name: ~str, weight: float }
+}
+
+let mut a: Animal = Dog(~"Cocoa", 37.2);
+a = Cat{ name: ~"Spotty", weight: 2.7 };
+~~~~
+
+In this example, `Cat` is a _struct-like enum variant_,
+whereas `Dog` is simply called an enum variant.
 ### Constants
 
 ~~~~~~~~ {.ebnf .gram}

branches/incoming/doc/tutorial.md

@@ -733,6 +733,24 @@ fn point_from_direction(dir: Direction) -> Point {
 }
 ~~~~
 
+A special kind of enum variant, called _struct-like enums_,
+can have its fields extracted with dot notation and not just destructuring.
+For example:
+
+~~~~
+# struct Point {x: float, y: float}
+# fn square(x: float) -> float { x * x }
+enum Shape {
+    Circle { center: Point, radius: float },
+    Rectangle { left: Point, right: Point }
+}
+fn area(sh: Shape) -> float {
+   match sh {
+      Circle(c) => float::consts::pi * square(c.radius),
+      Rectangle(r) => r.right.x - r.left.x * r.right.y - r.right.y
+   }
+}
+~~~~
 ## Tuples
 
 Tuples in Rust behave exactly like structs, except that their fields

branches/incoming/src/librustc/middle/trans/base.rs

@@ -545,7 +545,10 @@ fn iter_structural_ty(cx: block, av: ValueRef, t: ty::t,
                 j += 1u;
             }
           }
-          _ => cx.tcx().sess.bug(~"iter_variant: not a function type")
+          _ => cx.tcx().sess.bug(fmt!("iter_variant: not a function type: \
+                                       %s (variant name = %s)",
+                                      cx.ty_to_str(fn_ty),
+                                      cx.sess().str_of(variant.name)))
         }
         return cx;
     }

branches/incoming/src/librustc/middle/typeck/collect.rs

@@ -158,13 +158,26 @@ fn get_enum_variant_types(ccx: @crate_ctxt,
                 result_ty = Some(enum_ty);
             }
             ast::struct_variant_kind(struct_def) => {
-                result_ty = Some(enum_ty);
                 // XXX: Merge with computation of the the same value below?
                 let tpt = {bounds: ty_param_bounds(ccx, ty_params),
                            region_param: rp,
                            ty: enum_ty};
                 convert_struct(
                     ccx, rp, struct_def, ty_params, tpt, variant.node.id);
+                // Compute the ctor arg types from the struct fields
+                let struct_fields = do struct_def.fields.map |struct_field| {
+                    {mode: ast::expl(ast::by_val),
+                     ty: ty::node_id_to_type(ccx.tcx, (*struct_field).node.id)
+                    }
+                };
+                result_ty = Some(ty::mk_fn(tcx, FnTyBase {
+                    meta: FnMeta {purity: ast::pure_fn,
+                                  proto: ast::ProtoBare,
+                                  onceness: ast::Many,
+                                  bounds: @~[],
+                                  region: ty::re_static,
+                                  ret_style: ast::return_val},
+                    sig: FnSig {inputs: struct_fields, output: enum_ty }}));
             }
             ast::enum_variant_kind(ref enum_definition) => {
                 get_enum_variant_types(ccx,

branches/incoming/src/test/run-pass/enum-variants.rs

@@ -0,0 +1,11 @@
+enum Animal {
+    Dog (~str, float),
+    Cat { name: ~str, weight: float }
+}
+
+fn main() {
+    let mut a: Animal = Dog(~"Cocoa", 37.2);
+    a = Cat{ name: ~"Spotty", weight: 2.7 };
+    // permuting the fields should work too
+    let c = Cat { weight: 3.1, name: ~"Spreckles" };
+}