diff --git a/lib/std/io.zig b/lib/std/io.zig
index 25106e24be..09844bf055 100644
--- a/lib/std/io.zig
+++ b/lib/std/io.zig
@@ -17,9 +17,15 @@ const File = std.fs.File;
 const testing = std.testing;
 
 pub const Mode = enum {
+    /// I/O operates normally, waiting for the operating system syscalls to complete.
     blocking,
+
+    /// I/O functions are generated async and rely on a global event loop. Event-based I/O.
     evented,
 };
+
+/// The application's chosen I/O mode. This defaults to `Mode.blocking` but can be overridden
+/// by `root.event_loop`.
 pub const mode: Mode = if (@hasDecl(root, "io_mode"))
     root.io_mode
 else if (@hasDecl(root, "event_loop"))
diff --git a/lib/std/special/docs/main.js b/lib/std/special/docs/main.js
index 5ecc2c0545..4c8fd389f7 100644
--- a/lib/std/special/docs/main.js
+++ b/lib/std/special/docs/main.js
@@ -790,12 +790,19 @@
 
             var containerNode = zigAnalysis.astNodes[container.src];
             for (var i = 0; i < container.fields.length; i += 1) {
-                var fieldTypeIndex = container.fields[i];
+                var field = container.fields[i];
                 var fieldNode = zigAnalysis.astNodes[containerNode.fields[i]];
                 var divDom = domListFields.children[i];
 
-                var html = '<pre>' + escapeHtml(fieldNode.name) + ": " +
-                    typeIndexName(fieldTypeIndex, true, true) + ',</pre>';
+                var html = '<pre>' + escapeHtml(fieldNode.name);
+
+                if (container.kind === typeKinds.Enum) {
+                    html += ' = <span class="tok-number">' + field + '</span>';
+                } else {
+                    html += ": " + typeIndexName(field, true, true);
+                }
+
+                html += ',</pre>';
 
                 var docs = fieldNode.docs;
                 if (docs != null) {
diff --git a/src/dump_analysis.cpp b/src/dump_analysis.cpp
index ddf59097d7..6a3593ed58 100644
--- a/src/dump_analysis.cpp
+++ b/src/dump_analysis.cpp
@@ -216,6 +216,21 @@ static void jw_int(JsonWriter *jw, int64_t x) {
     jw_pop_state(jw);
 }
 
+static void jw_bigint(JsonWriter *jw, const BigInt *x) {
+    assert(jw->state[jw->state_index] == JsonWriterStateValue);
+    Buf *str = buf_alloc();
+    bigint_append_buf(str, x, 10);
+
+    if (bigint_fits_in_bits(x, 52, true)) {
+        fprintf(jw->f, "%s", buf_ptr(str));
+    } else {
+        fprintf(jw->f, "\"%s\"", buf_ptr(str));
+    }
+    jw_pop_state(jw);
+
+    buf_destroy(str);
+}
+
 static void jw_string(JsonWriter *jw, const char *s) {
     assert(jw->state[jw->state_index] == JsonWriterStateValue);
     jw_write_escaped_string(jw, s);
@@ -754,6 +769,10 @@ static void anal_dump_type(AnalDumpCtx *ctx, ZigType *ty) {
 
             jw_object_field(jw, "name");
             jw_string(jw, buf_ptr(&ty->name));
+
+            jw_object_field(jw, "src");
+            anal_dump_node_ref(ctx, ty->data.structure.decl_node);
+
             {
                 jw_object_field(jw, "pubDecls");
                 jw_begin_array(jw);
@@ -794,9 +813,6 @@ static void anal_dump_type(AnalDumpCtx *ctx, ZigType *ty) {
                 jw_end_array(jw);
             }
 
-            jw_object_field(jw, "src");
-            anal_dump_node_ref(ctx, ty->data.structure.decl_node);
-
             if (ty->data.structure.src_field_count != 0) {
                 jw_object_field(jw, "fields");
                 jw_begin_array(jw);
@@ -816,6 +832,124 @@ static void anal_dump_type(AnalDumpCtx *ctx, ZigType *ty) {
             }
             break;
         }
+        case ZigTypeIdUnion: {
+            jw_object_field(jw, "name");
+            jw_string(jw, buf_ptr(&ty->name));
+
+            jw_object_field(jw, "src");
+            anal_dump_node_ref(ctx, ty->data.unionation.decl_node);
+
+            {
+                jw_object_field(jw, "pubDecls");
+                jw_begin_array(jw);
+
+                ScopeDecls *decls_scope = ty->data.unionation.decls_scope;
+                auto it = decls_scope->decl_table.entry_iterator();
+                for (;;) {
+                    auto *entry = it.next();
+                    if (!entry)
+                        break;
+
+                    Tld *tld = entry->value;
+                    if (tld->visib_mod == VisibModPub) {
+                        jw_array_elem(jw);
+                        anal_dump_decl_ref(ctx, tld);
+                    }
+                }
+                jw_end_array(jw);
+            }
+
+            {
+                jw_object_field(jw, "privDecls");
+                jw_begin_array(jw);
+
+                ScopeDecls *decls_scope = ty->data.unionation.decls_scope;
+                auto it = decls_scope->decl_table.entry_iterator();
+                for (;;) {
+                    auto *entry = it.next();
+                    if (!entry)
+                        break;
+
+                    Tld *tld = entry->value;
+                    if (tld->visib_mod == VisibModPrivate) {
+                        jw_array_elem(jw);
+                        anal_dump_decl_ref(ctx, tld);
+                    }
+                }
+                jw_end_array(jw);
+            }
+
+            if (ty->data.unionation.src_field_count != 0) {
+                jw_object_field(jw, "fields");
+                jw_begin_array(jw);
+
+                for(size_t i = 0; i < ty->data.unionation.src_field_count; i += 1) {
+                    jw_array_elem(jw);
+                    anal_dump_type_ref(ctx, ty->data.unionation.fields[i].type_entry);
+                }
+                jw_end_array(jw);
+            }
+            break;
+        }
+        case ZigTypeIdEnum: {
+            jw_object_field(jw, "name");
+            jw_string(jw, buf_ptr(&ty->name));
+
+            jw_object_field(jw, "src");
+            anal_dump_node_ref(ctx, ty->data.enumeration.decl_node);
+
+            {
+                jw_object_field(jw, "pubDecls");
+                jw_begin_array(jw);
+
+                ScopeDecls *decls_scope = ty->data.enumeration.decls_scope;
+                auto it = decls_scope->decl_table.entry_iterator();
+                for (;;) {
+                    auto *entry = it.next();
+                    if (!entry)
+                        break;
+
+                    Tld *tld = entry->value;
+                    if (tld->visib_mod == VisibModPub) {
+                        jw_array_elem(jw);
+                        anal_dump_decl_ref(ctx, tld);
+                    }
+                }
+                jw_end_array(jw);
+            }
+
+            {
+                jw_object_field(jw, "privDecls");
+                jw_begin_array(jw);
+
+                ScopeDecls *decls_scope = ty->data.enumeration.decls_scope;
+                auto it = decls_scope->decl_table.entry_iterator();
+                for (;;) {
+                    auto *entry = it.next();
+                    if (!entry)
+                        break;
+
+                    Tld *tld = entry->value;
+                    if (tld->visib_mod == VisibModPrivate) {
+                        jw_array_elem(jw);
+                        anal_dump_decl_ref(ctx, tld);
+                    }
+                }
+                jw_end_array(jw);
+            }
+
+            if (ty->data.enumeration.src_field_count != 0) {
+                jw_object_field(jw, "fields");
+                jw_begin_array(jw);
+
+                for(size_t i = 0; i < ty->data.enumeration.src_field_count; i += 1) {
+                    jw_array_elem(jw);
+                    jw_bigint(jw, &ty->data.enumeration.fields[i].value);
+                }
+                jw_end_array(jw);
+            }
+            break;
+        }
         case ZigTypeIdFloat: {
             jw_object_field(jw, "bits");
             jw_int(jw, ty->data.floating.bit_count);