diff --git a/src/eval/eval_core.c b/src/eval/eval_core.c
index c9d9ddb6..b1759155 100644
--- a/src/eval/eval_core.c
+++ b/src/eval/eval_core.c
@@ -160,6 +160,17 @@ e_msg_list_concat_in_place(E_MsgList *dst, E_MsgList *to_push)
   MemoryZeroStruct(to_push);
 }
 
+internal E_MsgList
+e_msg_list_copy(Arena *arena, E_MsgList *src)
+{
+  E_MsgList dst = {0};
+  for(E_Msg *msg = src->first; msg != 0; msg = msg->next)
+  {
+    e_msg(arena, &dst, msg->kind, msg->location, msg->text);
+  }
+  return dst;
+}
+
 ////////////////////////////////
 //~ rjf: Space Functions
 
@@ -796,6 +807,8 @@ e_parse_from_bundle(E_CacheBundle *bundle)
   {
     bundle->flags |= E_CacheBundleFlag_Parse;
     bundle->parse = e_push_parse_from_string(e_cache->arena, bundle->string);
+    E_MsgList msgs_copy = e_msg_list_copy(e_cache->arena, &bundle->parse.msgs);
+    e_msg_list_concat_in_place(&bundle->msgs, &msgs_copy);
   }
   E_Parse parse = bundle->parse;
   return parse;
@@ -810,6 +823,8 @@ e_irtree_from_bundle(E_CacheBundle *bundle)
     E_IRTreeAndType overridden = e_irtree_from_key(bundle->parent_key);
     E_Parse parse = e_parse_from_bundle(bundle);
     bundle->irtree = e_push_irtree_and_type_from_expr(e_cache->arena, &overridden, 0, 0, parse.expr);
+    E_MsgList msgs_copy = e_msg_list_copy(e_cache->arena, &bundle->irtree.msgs);
+    e_msg_list_concat_in_place(&bundle->msgs, &msgs_copy);
   }
   E_IRTreeAndType result = bundle->irtree;
   return result;
@@ -839,6 +854,10 @@ e_interpretation_from_bundle(E_CacheBundle *bundle)
     bundle->flags |= E_CacheBundleFlag_Interpret;
     String8 bytecode = e_bytecode_from_bundle(bundle);
     E_Interpretation interpret = e_interpret(bytecode);
+    if(E_InterpretationCode_Good < interpret.code && interpret.code < E_InterpretationCode_COUNT)
+    {
+      e_msg(e_cache->arena, &bundle->msgs, E_MsgKind_InterpretationError, 0, e_interpretation_code_display_strings[interpret.code]);
+    }
     bundle->interpretation = interpret;
   }
   E_Interpretation interpret = bundle->interpretation;
@@ -857,6 +876,7 @@ e_eval_from_bundle(E_CacheBundle *bundle)
     .expr      = e_parse_from_bundle(bundle).expr,
     .irtree    = e_irtree_from_bundle(bundle),
     .bytecode  = e_bytecode_from_bundle(bundle),
+    .msgs      = bundle->msgs,
   };
   E_Interpretation interpretation = e_interpretation_from_bundle(bundle);
   eval.code = interpretation.code;
diff --git a/src/eval/eval_core.h b/src/eval/eval_core.h
index b56d64be..5159b1c6 100644
--- a/src/eval/eval_core.h
+++ b/src/eval/eval_core.h
@@ -887,6 +887,7 @@ struct E_CacheBundle
   E_IRTreeAndType irtree;
   String8 bytecode;
   E_Interpretation interpretation;
+  E_MsgList msgs;
 };
 
 typedef struct E_CacheNode E_CacheNode;
@@ -1026,6 +1027,7 @@ internal E_TypeKeyList e_type_key_list_copy(Arena *arena, E_TypeKeyList *src);
 internal void e_msg(Arena *arena, E_MsgList *msgs, E_MsgKind kind, void *location, String8 text);
 internal void e_msgf(Arena *arena, E_MsgList *msgs, E_MsgKind kind, void *location, char *fmt, ...);
 internal void e_msg_list_concat_in_place(E_MsgList *dst, E_MsgList *to_push);
+internal E_MsgList e_msg_list_copy(Arena *arena, E_MsgList *src);
 
 ////////////////////////////////
 //~ rjf: Space Functions
diff --git a/src/eval/eval_ir.c b/src/eval/eval_ir.c
index ce077dc8..52eda47a 100644
--- a/src/eval/eval_ir.c
+++ b/src/eval/eval_ir.c
@@ -493,14 +493,13 @@ E_TYPE_ACCESS_FUNCTION_DEF(default)
       E_Expr *exprr = exprl->next;
       E_IRTreeAndType l = *lhs_irtree;
       E_IRTreeAndType r = e_push_irtree_and_type_from_expr(arena, overridden, 0, 0, exprr);
+      e_msg_list_concat_in_place(&result.msgs, &r.msgs);
       E_TypeKey l_restype = e_type_key_unwrap(l.type_key, E_TypeUnwrapFlag_AllDecorative);
       E_TypeKey r_restype = e_type_key_unwrap(r.type_key, E_TypeUnwrapFlag_AllDecorative);
       E_TypeKind l_restype_kind = e_type_kind_from_key(l_restype);
       E_TypeKind r_restype_kind = e_type_kind_from_key(r_restype);
       E_TypeKey direct_type = e_type_key_unwrap(l_restype, E_TypeUnwrapFlag_All);
       U64 direct_type_size = e_type_byte_size_from_key(direct_type);
-      e_msg_list_concat_in_place(&result.msgs, &l.msgs);
-      e_msg_list_concat_in_place(&result.msgs, &r.msgs);
       
       // rjf: bad conditions? -> error if applicable, exit
       if(r.root->op == 0)
@@ -586,7 +585,7 @@ E_TYPE_ACCESS_FUNCTION_DEF(default)
 //- rjf: top-level irtree/type extraction
 
 internal E_IRTreeAndType
-e_push_irtree_and_type_from_expr(Arena *arena, E_IRTreeAndType *overridden, B32 disallow_autohooks, B32 disallow_chained_fastpaths, E_Expr *root_expr)
+e_push_irtree_and_type_from_expr(Arena *arena, E_IRTreeAndType *root_overridden, B32 disallow_autohooks, B32 disallow_chained_fastpaths, E_Expr *root_expr)
 {
   ProfBeginFunction();
   Temp scratch = scratch_begin(&arena, 1);
@@ -603,7 +602,7 @@ e_push_irtree_and_type_from_expr(Arena *arena, E_IRTreeAndType *overridden, B32
     E_Expr *expr;
     E_IRTreeAndType *prev;
   };
-  Task start_task = {0, root_expr, overridden};
+  Task start_task = {0, root_expr, root_overridden};
   Task *first_task = &start_task;
   Task *last_task = first_task;
   for(Task *t = first_task; t != 0; t = t->next)
@@ -614,9 +613,11 @@ e_push_irtree_and_type_from_expr(Arena *arena, E_IRTreeAndType *overridden, B32
     e_expr_poison(expr);
     
     //- rjf: select the task's previous ir-tree-and-type as the overridden tree
+    E_IRTreeAndType *overridden = 0;
     if(t->prev != 0)
     {
-      overridden = t->prev;
+      overridden = push_array(arena, E_IRTreeAndType, 1);
+      MemoryCopyStruct(overridden, t->prev);
     }
     
     //- rjf: do expr -> irtree generation for this expression
@@ -636,6 +637,7 @@ e_push_irtree_and_type_from_expr(Arena *arena, E_IRTreeAndType *overridden, B32
         // rjf: unpack left-hand-side
         E_Expr *lhs = expr->first;
         E_IRTreeAndType lhs_irtree = e_push_irtree_and_type_from_expr(arena, overridden, disallow_autohooks, disallow_chained_fastpaths, lhs);
+        e_msg_list_concat_in_place(&result.msgs, &lhs_irtree.msgs);
         
         // rjf: try all IR trees in chain
         for(E_IRTreeAndType *lhs_irtree_try = &lhs_irtree; lhs_irtree_try != 0; lhs_irtree_try = lhs_irtree_try->prev)
@@ -692,11 +694,11 @@ e_push_irtree_and_type_from_expr(Arena *arena, E_IRTreeAndType *overridden, B32
         // rjf: unpack operand
         E_Expr *r_expr = expr->first;
         E_IRTreeAndType r_tree = e_push_irtree_and_type_from_expr(arena, overridden, disallow_autohooks, disallow_chained_fastpaths, r_expr);
+        e_msg_list_concat_in_place(&result.msgs, &r_tree.msgs);
         E_TypeKey r_type = e_type_key_unwrap(r_tree.type_key, E_TypeUnwrapFlag_AllDecorative);
         E_TypeKind r_type_kind = e_type_kind_from_key(r_type);
         E_TypeKey r_type_direct = e_type_key_unwrap(r_type, E_TypeUnwrapFlag_All);
         U64 r_type_direct_size = e_type_byte_size_from_key(r_type_direct);
-        e_msg_list_concat_in_place(&result.msgs, &r_tree.msgs);
         
         // rjf: bad conditions? -> error if applicable, exit
         if(r_tree.root->op == 0)
@@ -751,10 +753,10 @@ e_push_irtree_and_type_from_expr(Arena *arena, E_IRTreeAndType *overridden, B32
         // rjf: unpack operand
         E_Expr *r_expr = expr->first;
         E_IRTreeAndType r_tree = e_push_irtree_and_type_from_expr(arena, overridden, disallow_autohooks, disallow_chained_fastpaths, r_expr);
+        e_msg_list_concat_in_place(&result.msgs, &r_tree.msgs);
         E_TypeKey r_type = r_tree.type_key;
         E_TypeKey r_type_unwrapped = e_type_key_unwrap(r_type, E_TypeUnwrapFlag_AllDecorative);
         E_TypeKind r_type_unwrapped_kind = e_type_kind_from_key(r_type_unwrapped);
-        e_msg_list_concat_in_place(&result.msgs, &r_tree.msgs);
         
         // rjf: bad conditions? -> error if applicable, exit
         if(r_tree.root->op == 0)
@@ -779,6 +781,7 @@ e_push_irtree_and_type_from_expr(Arena *arena, E_IRTreeAndType *overridden, B32
         E_Expr *cast_type_expr = expr->first;
         E_Expr *casted_expr = cast_type_expr->next;
         E_IRTreeAndType cast_irtree = e_push_irtree_and_type_from_expr(arena, overridden, disallow_autohooks, disallow_chained_fastpaths, cast_type_expr);
+        e_msg_list_concat_in_place(&result.msgs, &cast_irtree.msgs);
         E_TypeKey cast_type = cast_irtree.type_key;
         E_TypeKind cast_type_kind = e_type_kind_from_key(cast_type);
         U64 cast_type_byte_size = e_type_byte_size_from_key(cast_type);
@@ -915,12 +918,12 @@ e_push_irtree_and_type_from_expr(Arena *arena, E_IRTreeAndType *overridden, B32
         // rjf: unpack operand
         E_Expr *r_expr = expr->first;
         E_IRTreeAndType r_tree = e_push_irtree_and_type_from_expr(arena, overridden, disallow_autohooks, disallow_chained_fastpaths, r_expr);
+        e_msg_list_concat_in_place(&result.msgs, &r_tree.msgs);
         E_TypeKey r_type = e_type_key_unwrap(r_tree.type_key, E_TypeUnwrapFlag_AllDecorative);
         E_TypeKind r_type_kind = e_type_kind_from_key(r_type);
         RDI_EvalTypeGroup r_type_group = e_type_group_from_kind(r_type_kind);
         E_TypeKey r_type_promoted = e_type_key_promote(r_type);
         RDI_EvalOp op = e_opcode_from_expr_kind(kind);
-        e_msg_list_concat_in_place(&result.msgs, &r_tree.msgs);
         
         // rjf: bad conditions? -> error if applicable, exit
         if(r_tree.root->op == 0)
@@ -948,12 +951,12 @@ e_push_irtree_and_type_from_expr(Arena *arena, E_IRTreeAndType *overridden, B32
         // rjf: unpack operand
         E_Expr *r_expr = expr->first;
         E_IRTreeAndType r_tree = e_push_irtree_and_type_from_expr(arena, overridden, disallow_autohooks, disallow_chained_fastpaths, r_expr);
+        e_msg_list_concat_in_place(&result.msgs, &r_tree.msgs);
         E_TypeKey r_type = e_type_key_unwrap(r_tree.type_key, E_TypeUnwrapFlag_AllDecorative);
         E_TypeKind r_type_kind = e_type_kind_from_key(r_type);
         RDI_EvalTypeGroup r_type_group = e_type_group_from_kind(r_type_kind);
         E_TypeKey r_type_promoted = e_type_key_basic(E_TypeKind_Bool);
         RDI_EvalOp op = e_opcode_from_expr_kind(kind);
-        e_msg_list_concat_in_place(&result.msgs, &r_tree.msgs);
         
         // rjf: bad conditions? -> error if applicable, exit
         if(r_tree.root->op == 0)
@@ -1273,6 +1276,7 @@ e_push_irtree_and_type_from_expr(Arena *arena, E_IRTreeAndType *overridden, B32
       {
         E_Expr *lhs = expr->first;
         E_IRTreeAndType lhs_irtree = e_push_irtree_and_type_from_expr(arena, overridden, disallow_autohooks, 1, lhs);
+        e_msg_list_concat_in_place(&result.msgs, &lhs_irtree.msgs);
         E_TypeKey lhs_type_key = lhs_irtree.type_key;
         E_Type *lhs_type = e_type_from_key__cached(lhs_type_key);
         
@@ -1294,19 +1298,30 @@ e_push_irtree_and_type_from_expr(Arena *arena, E_IRTreeAndType *overridden, B32
             e_expr_push_child(call, e_expr_ref(arena, arg));
           }
           result = e_push_irtree_and_type_from_expr(arena, overridden, disallow_autohooks, disallow_chained_fastpaths, call);
+          E_MsgList new_msgs = {0};
+          e_msg_list_concat_in_place(&new_msgs, &lhs_irtree.msgs);
+          e_msg_list_concat_in_place(&new_msgs, &result.msgs);
+          result.msgs = new_msgs;
           
           // rjf: is "raw"? -> try to return overridden tree, otherwise strip all
           // lens types from result; disallow auto-hooks
           if(str8_match(callee->string, str8_lit("raw"), 0))
           {
             disallow_autohooks = 1;
-            if(overridden != 0)
+            if(overridden->root != &e_irnode_nil)
             {
-              result = *overridden;
-              for(E_IRTreeAndType *prev = overridden->prev; prev != 0; prev = prev->prev)
+              E_MsgList existing_msgs = result.msgs;
+              for(E_IRTreeAndType *prev = overridden; prev->root != &e_irnode_nil; prev = prev->prev)
               {
                 result = *prev;
+                if(e_type_kind_from_key(prev->type_key) != E_TypeKind_Lens)
+                {
+                  break;
+                }
               }
+              E_MsgList overridden_msgs = e_msg_list_copy(arena, &result.msgs);
+              result.msgs = existing_msgs;
+              e_msg_list_concat_in_place(&result.msgs, &overridden_msgs);
             }
             else
             {
@@ -1322,7 +1337,7 @@ e_push_irtree_and_type_from_expr(Arena *arena, E_IRTreeAndType *overridden, B32
           Temp scratch = scratch_begin(&arena, 1);
           
           // rjf: generate result via first argument to lens
-          result = e_push_irtree_and_type_from_expr(arena, overridden, disallow_autohooks, disallow_chained_fastpaths, lhs->next);
+          result = e_push_irtree_and_type_from_expr(arena, overridden, disallow_autohooks, 1, lhs->next);
           
           // rjf: count extra arguments
           U64 arg_count = 0;
@@ -1346,17 +1361,25 @@ e_push_irtree_and_type_from_expr(Arena *arena, E_IRTreeAndType *overridden, B32
           if(str8_match(lhs_type->name, str8_lit("raw"), 0))
           {
             disallow_autohooks = 1;
-            if(overridden != 0)
+            if(overridden->root != &e_irnode_nil)
             {
+              E_MsgList existing_msgs = result.msgs;
               result = *overridden;
-              for(E_IRTreeAndType *prev = overridden->prev; prev != 0; prev = prev->prev)
+              for(E_IRTreeAndType *prev = overridden; prev->root != &e_irnode_nil; prev = prev->prev)
               {
                 result = *prev;
+                if(e_type_kind_from_key(prev->type_key) != E_TypeKind_Lens)
+                {
+                  break;
+                }
               }
+              E_MsgList overridden_msgs = e_msg_list_copy(arena, &result.msgs);
+              result.msgs = existing_msgs;
+              e_msg_list_concat_in_place(&result.msgs, &overridden_msgs);
             }
             else
             {
-              result = e_push_irtree_and_type_from_expr(arena, overridden, disallow_autohooks, disallow_chained_fastpaths, lhs->next);
+              result = e_push_irtree_and_type_from_expr(arena, overridden, disallow_autohooks, 1, lhs->next);
               result.type_key = e_type_key_unwrap(result.type_key, E_TypeUnwrapFlag_Lenses);
             }
           }
@@ -1484,7 +1507,7 @@ e_push_irtree_and_type_from_expr(Arena *arena, E_IRTreeAndType *overridden, B32
         }
         
         //- rjf: try to map name as overridden expression signifier ('$')
-        if(!string_mapped && str8_match(string, str8_lit("$"), 0) && overridden != 0)
+        if(!string_mapped && str8_match(string, str8_lit("$"), 0) && (overridden->root != &e_irnode_nil || overridden->msgs.first != 0))
         {
           E_OpList oplist = e_oplist_from_irtree(arena, overridden->root);
           string_mapped = 1;
@@ -1492,11 +1515,14 @@ e_push_irtree_and_type_from_expr(Arena *arena, E_IRTreeAndType *overridden, B32
           mapped_bytecode_mode = overridden->mode;
           mapped_type_key = overridden->type_key;
           disallow_autohooks = 1;
+          E_MsgList msgs = e_msg_list_copy(arena, &overridden->msgs);
+          e_msg_list_concat_in_place(&result.msgs, &msgs);
         }
         
         //- rjf: try to map name as implicit access of overridden expression ('$.member_name', where the $. prefix is omitted)
-        if(!string_mapped && overridden != 0)
+        if(!string_mapped && overridden->root != &e_irnode_nil)
         {
+          // TODO(rjf): @eval
           E_Expr *access = e_expr_irext_member_access(scratch.arena, &e_expr_nil, overridden, string);
           E_IRTreeAndType access_irtree = e_push_irtree_and_type_from_expr(scratch.arena, overridden, disallow_autohooks, disallow_chained_fastpaths, access);
           if(access_irtree.root != &e_irnode_nil)
@@ -1506,6 +1532,7 @@ e_push_irtree_and_type_from_expr(Arena *arena, E_IRTreeAndType *overridden, B32
             mapped_type_key = access_irtree.type_key;
             mapped_bytecode = e_bytecode_from_oplist(arena, &oplist);
             mapped_bytecode_mode = access_irtree.mode;
+            e_msg_list_concat_in_place(&result.msgs, &access_irtree.msgs);
           }
         }
         
@@ -1884,7 +1911,7 @@ e_push_irtree_and_type_from_expr(Arena *arena, E_IRTreeAndType *overridden, B32
         }
         
         //- rjf: error on failure-to-generate
-        if(!generated)
+        if(!generated && !str8_match(string, str8_lit("$"), 0))
         {
           e_msgf(arena, &result.msgs, E_MsgKind_ResolutionFailure, expr->location, "`%S` could not be found.", string);
         }
@@ -2066,8 +2093,7 @@ e_push_irtree_and_type_from_expr(Arena *arena, E_IRTreeAndType *overridden, B32
     //- rjf: equip previous task's irtree
     if(t->prev != 0)
     {
-      result.prev = push_array(arena, E_IRTreeAndType, 1);
-      result.prev[0] = *t->prev;
+      result.prev = overridden;
     }
     
     //- rjf: find any auto hooks according to this generation's type
@@ -2084,8 +2110,7 @@ e_push_irtree_and_type_from_expr(Arena *arena, E_IRTreeAndType *overridden, B32
             Task *task = push_array(scratch.arena, Task, 1);
             SLLQueuePush(first_task, last_task, task);
             task->expr = e;
-            task->prev = push_array(scratch.arena, E_IRTreeAndType, 1);
-            task->prev[0] = result;
+            task->prev = &result;
             break;
           }
         }
diff --git a/src/eval/eval_ir.h b/src/eval/eval_ir.h
index 2bc467dd..c98a70fa 100644
--- a/src/eval/eval_ir.h
+++ b/src/eval/eval_ir.h
@@ -88,7 +88,7 @@ internal void e_expr_unpoison(E_Expr *expr);
 
 //- rjf: top-level irtree/type extraction
 E_TYPE_ACCESS_FUNCTION_DEF(default);
-internal E_IRTreeAndType e_push_irtree_and_type_from_expr(Arena *arena, E_IRTreeAndType *overridden, B32 disallow_autohooks, B32 disallow_chained_fastpaths, E_Expr *root_expr);
+internal E_IRTreeAndType e_push_irtree_and_type_from_expr(Arena *arena, E_IRTreeAndType *root_overridden, B32 disallow_autohooks, B32 disallow_chained_fastpaths, E_Expr *root_expr);
 
 //- rjf: irtree -> linear ops/bytecode
 internal void e_append_oplist_from_irtree(Arena *arena, E_IRNode *root, E_Space *current_space, E_OpList *out);
diff --git a/src/eval/eval_types.c b/src/eval/eval_types.c
index 5b4d4d97..8f4fe480 100644
--- a/src/eval/eval_types.c
+++ b/src/eval/eval_types.c
@@ -1367,7 +1367,7 @@ e_type_data_members_from_key(Arena *arena, E_TypeKey key)
       padding_member->kind = E_MemberKind_Padding;
       padding_member->type_key = e_type_key_cons_array(e_type_key_basic(E_TypeKind_U8), n->size, E_TypeFlag_IsNotText);
       padding_member->off = n->off;
-      padding_member->name = push_str8f(arena, "[padding %I64u]", padding_idx);
+      padding_member->name = push_str8f(arena, "$padding_%I64u", padding_idx);
       padding_idx += 1;
     }
     members = new_members;
@@ -2355,13 +2355,21 @@ E_TYPE_EXPAND_RANGE_FUNCTION_DEF(array)
   U64 read_range_count = dim_1u64(idx_range);
   for(U64 idx = 0; idx < read_range_count; idx += 1)
   {
-    evals_out[idx] = e_eval_wrapf(eval, "$[I64u]", idx_range.min + idx);
+    evals_out[idx] = e_eval_wrapf(eval, "$[%I64u]", idx_range.min + idx);
   }
 }
 
 ////////////////////////////////
 //~ rjf: (Built-In Type Hooks) `slice` lens
 
+typedef struct E_SliceIRExt E_SliceIRExt;
+struct E_SliceIRExt
+{
+  E_Member *base_ptr_member;
+  E_Member *opl_ptr_member;
+  E_Member *count_member;
+};
+
 typedef struct E_SliceAccel E_SliceAccel;
 struct E_SliceAccel
 {
@@ -2373,7 +2381,7 @@ struct E_SliceAccel
 
 E_TYPE_IREXT_FUNCTION_DEF(slice)
 {
-  E_SliceAccel *accel = push_array(arena, E_SliceAccel, 1);
+  E_SliceIRExt *ext = push_array(arena, E_SliceIRExt, 1);
   {
     Temp scratch = scratch_begin(&arena, 1);
     
@@ -2416,77 +2424,21 @@ E_TYPE_IREXT_FUNCTION_DEF(slice)
         }
       }
       
-      // rjf: determine architecture
-      Arch arch = e_base_ctx->primary_module->arch;
-      if(base_ptr_member != 0)
-      {
-        E_Type *type = e_type_from_key__cached(base_ptr_member->type_key);
-        arch = type->arch;
-      }
-      
-      // rjf: evaluate count member, determine count
-      U64 count = 0;
-      if(count_member != 0)
-      {
-        E_Expr *count_member_expr = e_expr_irext_member_access(arena, expr, irtree, count_member->name);
-        E_Value count_member_value = e_value_from_expr(count_member_expr);
-        count = count_member_value.u64;
-      }
-      
-      // rjf: evaluate base ptr member, determine base address
-      U64 base_ptr_vaddr = 0;
-      if(base_ptr_member != 0)
-      {
-        E_Expr *base_ptr_member_expr = e_expr_irext_member_access(arena, expr, irtree, base_ptr_member->name);
-        E_Value base_ptr_member_value = e_value_from_expr(base_ptr_member_expr);
-        base_ptr_vaddr = base_ptr_member_value.u64;
-      }
-      
-      // rjf: evaluate opl ptr member, determine opl address
-      U64 opl_ptr_vaddr = 0;
-      if(count_member == 0 && opl_ptr_member != 0)
-      {
-        E_Expr *opl_ptr_member_expr = e_expr_irext_member_access(arena, expr, irtree, opl_ptr_member->name);
-        E_Value opl_ptr_member_value = e_value_from_expr(opl_ptr_member_expr);
-        opl_ptr_vaddr = opl_ptr_member_value.u64;
-      }
-      
-      // rjf: determine element type
-      E_TypeKey element_type_key = zero_struct;
-      if(base_ptr_member != 0)
-      {
-        element_type_key = e_type_key_direct(base_ptr_member->type_key);
-      }
-      
-      // rjf: if no count, but base/opl, swap base/opl if needed, and measure count
-      if(count_member == 0 && opl_ptr_member != 0 && base_ptr_member != 0)
-      {
-        U64 min_vaddr = Min(base_ptr_vaddr, opl_ptr_vaddr);
-        U64 max_vaddr = Max(base_ptr_vaddr, opl_ptr_vaddr);
-        base_ptr_vaddr = min_vaddr;
-        opl_ptr_vaddr = max_vaddr;
-        count = (opl_ptr_vaddr - base_ptr_vaddr) / e_type_byte_size_from_key(element_type_key);
-      }
-      
-      // rjf: fill
-      if((count_member || opl_ptr_member) && base_ptr_member)
-      {
-        accel->arch = arch;
-        accel->count = count;
-        accel->base_ptr_vaddr = base_ptr_vaddr;
-        accel->element_type_key = element_type_key;
-      }
+      // rjf: fill extension
+      ext->base_ptr_member = base_ptr_member;
+      ext->opl_ptr_member = opl_ptr_member;
+      ext->count_member = count_member;
     }
     scratch_end(scratch);
   }
-  E_IRExt result = {accel};
+  E_IRExt result = {ext};
   return result;
 }
 
 E_TYPE_ACCESS_FUNCTION_DEF(slice)
 {
   E_IRTreeAndType result = {&e_irnode_nil};
-  E_SliceAccel *accel = (E_SliceAccel *)lhs_irtree->user_data;
+  E_SliceIRExt *ext = (E_SliceIRExt *)lhs_irtree->user_data;
   switch(expr->kind)
   {
     default:
@@ -2495,18 +2447,37 @@ E_TYPE_ACCESS_FUNCTION_DEF(slice)
       result = E_TYPE_ACCESS_FUNCTION_NAME(default)(arena, overridden, expr, lhs_irtree);
     }break;
     case E_ExprKind_ArrayIndex:
+    if(ext->base_ptr_member != 0)
     {
-      E_Value rhs_value = e_value_from_expr(expr->first->next);
-      U64 rhs_idx = rhs_value.u64;
-      if(0 <= rhs_idx && rhs_idx < accel->count)
+      Temp scratch = scratch_begin(&arena, 1);
+      
+      // rjf: compute bytecode of struct
+      E_OpList lhs_oplist = e_oplist_from_irtree(scratch.arena, lhs_irtree->root);
+      String8 lhs_bytecode = e_bytecode_from_oplist(arena, &lhs_oplist);
+      
+      // rjf: build expression tree to access base pointer's member, then do an index
+      E_Expr *idx_expr = e_push_expr(scratch.arena, E_ExprKind_ArrayIndex, 0);
+      E_Expr *dot_expr = e_push_expr(scratch.arena, E_ExprKind_MemberAccess, 0);
+      E_Expr *lhs_expr = e_push_expr(scratch.arena, E_ExprKind_LeafBytecode, 0);
+      E_Expr *base_ptr_expr = e_push_expr(scratch.arena, E_ExprKind_LeafIdentifier, 0);
+      e_expr_push_child(dot_expr, lhs_expr);
+      e_expr_push_child(dot_expr, base_ptr_expr);
+      e_expr_push_child(idx_expr, dot_expr);
+      e_expr_push_child(idx_expr, e_expr_ref(scratch.arena, expr->first->next));
       {
-        E_Type *element_type = e_type_from_key__cached(accel->element_type_key);
-        U64 offset = element_type->byte_size*rhs_idx;
-        U64 vaddr = accel->base_ptr_vaddr + offset;
-        result.root = e_irtree_const_u(arena, vaddr);
-        result.type_key = accel->element_type_key;
-        result.mode = E_Mode_Offset;
+        lhs_expr->mode = lhs_irtree->mode;
+        lhs_expr->bytecode = lhs_bytecode;
+        lhs_expr->type_key = e_type_key_unwrap(lhs_irtree->type_key, E_TypeUnwrapFlag_Lenses);
       }
+      {
+        base_ptr_expr->string = ext->base_ptr_member->name;
+      }
+      
+      // rjf: compute struct.base_ptr IR tree
+      E_IRTreeAndType override = {&e_irnode_nil};
+      result = e_push_irtree_and_type_from_expr(arena, &override, 0, 0, idx_expr);
+      
+      scratch_end(scratch);
     }break;
   }
   return result;
@@ -2514,8 +2485,19 @@ E_TYPE_ACCESS_FUNCTION_DEF(slice)
 
 E_TYPE_EXPAND_INFO_FUNCTION_DEF(slice)
 {
-  E_SliceAccel *accel = (E_SliceAccel *)eval.irtree.user_data;
-  E_TypeExpandInfo info = {accel, accel->count};
+  E_SliceIRExt *accel = (E_SliceIRExt *)eval.irtree.user_data;
+  U64 count = 0;
+  {
+    if(accel->count_member != 0)
+    {
+      count = e_value_eval_from_eval(e_eval_wrapf(eval, "$.%S", accel->count_member->name)).value.u64;
+    }
+    else if(accel->opl_ptr_member != 0 && accel->base_ptr_member != 0)
+    {
+      count = e_value_eval_from_eval(e_eval_wrapf(eval, "$.%S - $.%S", accel->opl_ptr_member->name, accel->base_ptr_member->name)).value.u64;
+    }
+  }
+  E_TypeExpandInfo info = {0, count};
   return info;
 }
 
@@ -2611,7 +2593,7 @@ E_TYPE_EXPAND_RANGE_FUNCTION_DEF(folder)
     {
       String8 folder_name = accel->folders.v[idx - 0];
       String8 folder_path = push_str8f(scratch.arena, "%S%s%S", accel->folder_path, accel->folder_path.size != 0 ? "/" : "", folder_name);
-      path_expr_string = push_str8f(arena, "file:\"%S\"", escaped_from_raw_str8(scratch.arena, folder_path));
+      path_expr_string = push_str8f(arena, "folder:\"%S/\"", escaped_from_raw_str8(scratch.arena, folder_path));
     }
     else if(accel->folders.count <= idx && idx < accel->folders.count + accel->files.count)
     {
diff --git a/src/eval_visualization/eval_visualization_core.c b/src/eval_visualization/eval_visualization_core.c
index 422ff1ec..086b1605 100644
--- a/src/eval_visualization/eval_visualization_core.c
+++ b/src/eval_visualization/eval_visualization_core.c
@@ -542,12 +542,13 @@ ev_block_tree_from_eval(Arena *arena, EV_View *view, String8 filter, E_Eval eval
       Task *next;
       EV_Block *parent_block;
       E_Eval eval;
+      E_Expr *next_expr;
       U64 child_id;
       U64 split_relative_idx;
       B32 default_expanded;
       B32 force_expanded;
     };
-    Task start_task = {0, tree.root, tree.root->eval, 1, 0};
+    Task start_task = {0, tree.root, tree.root->eval, tree.root->eval.expr->next, 1, 0};
     Task *first_task = &start_task;
     Task *last_task = first_task;
     
@@ -708,6 +709,7 @@ ev_block_tree_from_eval(Arena *arena, EV_View *view, String8 filter, E_Eval eval
           SLLQueuePush(first_task, last_task, task);
           task->parent_block       = expansion_block;
           task->eval               = child_eval;
+          task->next_expr          = &e_expr_nil;
           task->child_id           = child_key.child_id;
           task->split_relative_idx = split_relative_idx;
           task->default_expanded   = viz_expand_info.rows_default_expanded;
@@ -715,13 +717,14 @@ ev_block_tree_from_eval(Arena *arena, EV_View *view, String8 filter, E_Eval eval
       }
       
       // rjf: if this expr has a sibling, push another task to continue the chain
-      if(t->eval.expr->next != &e_expr_nil)
+      if(t->next_expr != &e_expr_nil)
       {
         Task *task = push_array(scratch.arena, Task, 1);
         task->next = t->next;
         t->next = task;
         task->parent_block       = t->parent_block;
-        task->eval               = e_eval_from_expr(t->eval.expr->next);
+        task->eval               = e_eval_from_expr(t->next_expr);
+        task->next_expr          = t->next_expr->next;
         task->child_id           = t->child_id + 1;
         task->split_relative_idx = 0;
         task->default_expanded   = t->default_expanded;
@@ -2048,8 +2051,7 @@ ev_string_iter_next(Arena *arena, EV_StringIter *it, String8 *out_string)
               // rjf: single-length pointers -> just gen new task for deref'd expr
               if(ptr_data->type->count == 1)
               {
-                E_Expr *deref_expr = e_expr_irext_deref(arena, eval.expr, &eval.irtree);
-                E_Eval deref_eval = e_eval_from_expr(deref_expr);
+                E_Eval deref_eval = e_eval_wrapf(eval, "*$");
                 need_new_task = 1;
                 need_pop = 0;
                 new_task.params = *params;
@@ -2121,9 +2123,9 @@ ev_string_iter_next(Arena *arena, EV_StringIter *it, String8 *out_string)
           //- rjf: middle step -> generate new task for next thing in expansion
           else
           {
-            E_Eval next_eval = {0};
+            E_Eval next_eval = e_eval_nil;
             expand_data->expand_rule->range(arena, expand_data->expand_info.user_data, eval, params->filter, r1u64(task_idx-1, task_idx), &next_eval);
-            if(next_eval.expr != 0 && next_eval.expr != &e_expr_nil)
+            if(next_eval.expr != &e_expr_nil)
             {
               need_new_task = 1;
               need_pop = 0;
diff --git a/src/raddbg/raddbg_eval.c b/src/raddbg/raddbg_eval.c
index d8eeea5f..b122e5e1 100644
--- a/src/raddbg/raddbg_eval.c
+++ b/src/raddbg/raddbg_eval.c
@@ -683,9 +683,9 @@ E_TYPE_ACCESS_FUNCTION_DEF(cfgs)
     {
       String8 rhs_name = expr->first->next->string;
       RD_CfgID id = 0;
-      if(str8_match(str8_prefix(rhs_name, 1), str8_lit("$"), 0) &&
-         try_u64_from_str8_c_rules(str8_skip(rhs_name, 1), &id))
+      if(str8_match(str8_prefix(rhs_name, 1), str8_lit("$"), 0))
       {
+        id = u64_from_str8(str8_skip(rhs_name, 1), 16);
         cfg = rd_cfg_from_id(id);
       }
     }break;
@@ -777,7 +777,7 @@ E_TYPE_EXPAND_RANGE_FUNCTION_DEF(cfgs)
     for(U64 idx = 0; idx < read_count; idx += 1, dst_idx += 1)
     {
       RD_Cfg *cfg = accel->cfgs.v[idx + read_range.min - cfgs_idx_range.min];
-      evals_out[dst_idx] = e_eval_wrapf(eval, "$.$%I64d", cfg->id);
+      evals_out[dst_idx] = e_eval_from_stringf("$%I64x", cfg->id);
     }
   }
 }
diff --git a/src/raddbg/raddbg_views.c b/src/raddbg/raddbg_views.c
index fdd40619..7327ed07 100644
--- a/src/raddbg/raddbg_views.c
+++ b/src/raddbg/raddbg_views.c
@@ -1509,6 +1509,35 @@ rd_info_from_watch_row_cell(Arena *arena, EV_Row *row, EV_StringFlags string_fla
     {
       if(0){}
       
+      //- rjf: errors
+      else if(cell->eval.msgs.max_kind > E_MsgKind_Null && !(cell->flags & RD_WatchCellFlag_NoEval))
+      {
+        RD_Font(RD_FontSlot_Main)
+        {
+          DR_FStrParams params = {rd_font_from_slot(RD_FontSlot_Main), rd_raster_flags_from_slot(RD_FontSlot_Main), ui_color_from_name(str8_lit("text")), ui_top_font_size()};
+          DR_FStrList fstrs = {0};
+          UI_TagF("weak")
+          {
+            dr_fstrs_push_new(arena, &fstrs, &params,
+                              rd_icon_kind_text_table[RD_IconKind_WarningBig],
+                              .font = rd_font_from_slot(RD_FontSlot_Icons),
+                              .raster_flags = rd_raster_flags_from_slot(RD_FontSlot_Icons),
+                              .color = ui_color_from_name(str8_lit("text")));
+            dr_fstrs_push_new(arena, &fstrs, &params, str8_lit("  "));
+            for(E_Msg *msg = cell->eval.msgs.first; msg != 0; msg = msg->next)
+            {
+              DR_FStrList msg_fstrs = rd_fstrs_from_rich_string(arena, msg->text);
+              dr_fstrs_concat_in_place(&fstrs, &msg_fstrs);
+              if(msg->next)
+              {
+                dr_fstrs_push_new(arena, &fstrs, &params, str8_lit(" "));
+              }
+            }
+          }
+          result.expr_fstrs = fstrs;
+        }
+      }
+      
       //- rjf: cfg evaluation -> button for cfg
       else if(result.cfg != &rd_nil_cfg)
       {
diff --git a/src/raddbg/raddbg_widgets.c b/src/raddbg/raddbg_widgets.c
index 3fd8a761..2503a391 100644
--- a/src/raddbg/raddbg_widgets.c
+++ b/src/raddbg/raddbg_widgets.c
@@ -2595,12 +2595,12 @@ rd_code_slice(RD_CodeSliceParams *params, TxtPt *cursor, TxtPt *mark, S64 *prefe
           S64 column = cursor->column;
           Vec2F32 advance = fnt_dim_from_tag_size_string(line_box->font, line_box->font_size, 0, params->tab_size, str8_prefix(line_string, column-1));
           F32 cursor_off_pixels = advance.x;
-          F32 cursor_thickness = ClampBot(4.f, line_box->font_size/6.f);
+          F32 cursor_thickness = ClampBot(1.f, floor_f32(line_box->font_size/10.f));
           Rng2F32 cursor_rect =
           {
-            ui_box_text_position(line_box).x+cursor_off_pixels-cursor_thickness/2.f,
+            ui_box_text_position(line_box).x+cursor_off_pixels,
             line_box->rect.y0-params->font_size*0.125f,
-            ui_box_text_position(line_box).x+cursor_off_pixels+cursor_thickness/2.f,
+            ui_box_text_position(line_box).x+cursor_off_pixels+cursor_thickness,
             line_box->rect.y1+params->font_size*0.125f,
           };
           Vec4F32 cursor_color = ui_color_from_name(str8_lit("cursor"));
@@ -2608,7 +2608,7 @@ rd_code_slice(RD_CodeSliceParams *params, TxtPt *cursor, TxtPt *mark, S64 *prefe
           {
             cursor_color.w *= 0.5f;
           }
-          dr_rect(cursor_rect, cursor_color, 1.f, 0, 1.f);
+          dr_rect(cursor_rect, cursor_color, 1.f, 0, 0.f);
         }
         
         // rjf: extra rendering for lines with line-info that match the hovered
@@ -2849,10 +2849,10 @@ rd_do_txt_controls(TXT_TextInfo *info, String8 data, U64 line_count_per_page, Tx
 ////////////////////////////////
 //~ rjf: UI Widgets: Fancy Labels
 
-internal UI_Signal
-rd_label(String8 string)
+internal DR_FStrList
+rd_fstrs_from_rich_string(Arena *arena, String8 string)
 {
-  Temp scratch = scratch_begin(0, 0);
+  Temp scratch = scratch_begin(&arena, 1);
   typedef U32 StringPartFlags;
   enum
   {
@@ -2907,8 +2907,17 @@ rd_label(String8 string)
         fstr.params.color = rd_rgba_from_theme_color(RD_ThemeColor_CodeDefault);
       }
     }
-    dr_fstrs_push(scratch.arena, &fstrs, &fstr);
+    dr_fstrs_push(arena, &fstrs, &fstr);
   }
+  scratch_end(scratch);
+  return fstrs;
+}
+
+internal UI_Signal
+rd_label(String8 string)
+{
+  Temp scratch = scratch_begin(0, 0);
+  DR_FStrList fstrs = rd_fstrs_from_rich_string(scratch.arena, string);
   UI_Box *box = ui_build_box_from_key(UI_BoxFlag_DrawText, ui_key_zero());
   ui_box_equip_display_fstrs(box, &fstrs);
   UI_Signal sig = ui_signal_from_box(box);
diff --git a/src/raddbg/raddbg_widgets.h b/src/raddbg/raddbg_widgets.h
index d0622470..f801fc1a 100644
--- a/src/raddbg/raddbg_widgets.h
+++ b/src/raddbg/raddbg_widgets.h
@@ -160,6 +160,7 @@ internal B32 rd_do_txt_controls(TXT_TextInfo *info, String8 data, U64 line_count
 ////////////////////////////////
 //~ rjf: UI Widgets: Fancy Labels
 
+internal DR_FStrList rd_fstrs_from_rich_string(Arena *arena, String8 string);
 internal UI_Signal rd_label(String8 string);
 internal UI_Signal rd_error_label(String8 string);
 internal B32 rd_help_label(String8 string);
diff --git a/src/ui/ui_basic_widgets.c b/src/ui/ui_basic_widgets.c
index c2e8c2e7..acf08194 100644
--- a/src/ui/ui_basic_widgets.c
+++ b/src/ui/ui_basic_widgets.c
@@ -143,24 +143,24 @@ internal UI_BOX_CUSTOM_DRAW(ui_line_edit_draw)
   TxtPt mark = draw_data->mark;
   F32 cursor_pixel_off = fnt_dim_from_tag_size_string(font, font_size, 0, tab_size, str8_prefix(edited_string, cursor.column-1)).x;
   F32 mark_pixel_off   = fnt_dim_from_tag_size_string(font, font_size, 0, tab_size, str8_prefix(edited_string, mark.column-1)).x;
-  F32 cursor_thickness = ClampBot(4.f, font_size/6.f);
+  F32 cursor_thickness = ClampBot(1.f, floor_f32(font_size/10.f));
   Rng2F32 cursor_rect =
   {
-    text_position.x + cursor_pixel_off - cursor_thickness*0.50f,
+    text_position.x + cursor_pixel_off,
     box->parent->parent->rect.y0+ui_top_font_size()*0.5f,
-    text_position.x + cursor_pixel_off + cursor_thickness*0.50f,
+    text_position.x + cursor_pixel_off + cursor_thickness,
     box->parent->parent->rect.y1-ui_top_font_size()*0.5f,
   };
   Rng2F32 mark_rect =
   {
-    text_position.x + mark_pixel_off - cursor_thickness*0.50f,
+    text_position.x + mark_pixel_off - cursor_thickness,
     box->parent->parent->rect.y0+ui_top_font_size()*0.5f,
-    text_position.x + mark_pixel_off + cursor_thickness*0.50f,
+    text_position.x + mark_pixel_off + cursor_thickness,
     box->parent->parent->rect.y1-ui_top_font_size()*0.5f,
   };
   Rng2F32 select_rect = union_2f32(cursor_rect, mark_rect);
   dr_rect(select_rect, select_color, font_size/2.f, 0, 1.f);
-  dr_rect(cursor_rect, cursor_color, 0.f, 0, 1.f);
+  dr_rect(cursor_rect, cursor_color, 0.f, 0, 0.f);
 }
 
 internal UI_Signal