From 73da3c9e4c6d1246452d0d95a1ea37e9a7a90215 Mon Sep 17 00:00:00 2001
From: joe-conigliaro <joe@vlang.io>
Date: Tue, 30 Jun 2020 09:22:15 +1000
Subject: [PATCH] generic structs: better naming & comments

---
 vlib/v/builder/c.v         |  2 +-
 vlib/v/builder/generics.v  | 12 +++++++-----
 vlib/v/gen/js/js.v         |  2 +-
 vlib/v/parser/parse_type.v |  4 ++--
 vlib/v/table/atypes.v      |  9 +++++----
 5 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/vlib/v/builder/c.v b/vlib/v/builder/c.v
index 54c5e8c69f..34f57fddd2 100644
--- a/vlib/v/builder/c.v
+++ b/vlib/v/builder/c.v
@@ -14,7 +14,7 @@ pub fn (mut b Builder) gen_c(v_files []string) string {
 	parse_time := t1 - t0
 	b.info('PARSE: ${parse_time}ms')
 	//
-	b.instantiate_generic_structs()
+	b.generic_struct_insts_to_concrete()
 	b.checker.check_files(b.parsed_files)
 	t2 := time.ticks()
 	check_time := t2 - t1
diff --git a/vlib/v/builder/generics.v b/vlib/v/builder/generics.v
index 75533b4338..881164924b 100644
--- a/vlib/v/builder/generics.v
+++ b/vlib/v/builder/generics.v
@@ -2,15 +2,16 @@ module builder
 
 import v.table
 
-pub fn (b &Builder) instantiate_generic_structs() {
+// generic struct instantiations to concrete types
+pub fn (b &Builder) generic_struct_insts_to_concrete() {
 	for idx, _ in b.table.types {
 		mut typ := &b.table.types[idx]
-		if typ.kind == .generic_struct_instance {
-			info := typ.info as table.GenericStructInstance
+		if typ.kind == .generic_struct_inst {
+			info := typ.info as table.GenericStructInst
 			parent := b.table.types[info.parent_idx]
 			mut parent_info := *(parent.info as table.Struct)
 			mut fields := parent_info.fields.clone()
-			for i, _ in parent_info.fields {
+			for i, _ in fields {
 				mut field := fields[i]
 				if field.typ.has_flag(.generic) {
 					if parent_info.generic_types.len != info.generic_types.len {
@@ -27,9 +28,10 @@ pub fn (b &Builder) instantiate_generic_structs() {
 				fields[i] = field
 			}
 			parent_info.generic_types = []
+			parent_info.fields = fields
 			typ.is_public = true
 			typ.kind = .struct_
-			typ.info = {parent_info| fields: fields}
+			typ.info = parent_info
 		}
 	}
 }
\ No newline at end of file
diff --git a/vlib/v/gen/js/js.v b/vlib/v/gen/js/js.v
index 8dc1492112..16e3b125a2 100644
--- a/vlib/v/gen/js/js.v
+++ b/vlib/v/gen/js/js.v
@@ -238,7 +238,7 @@ pub fn (mut g JsGen) typ(t table.Type) string {
 		.struct_ {
 			styp = g.struct_typ(sym.name)
 		}
-		.generic_struct_instance {}
+		.generic_struct_inst {}
 		// 'multi_return_int_int' => '[number, number]'
 		.multi_return {
 			info := sym.info as table.MultiReturn
diff --git a/vlib/v/parser/parse_type.v b/vlib/v/parser/parse_type.v
index 9d3bd347b7..af7da87cc5 100644
--- a/vlib/v/parser/parse_type.v
+++ b/vlib/v/parser/parse_type.v
@@ -314,9 +314,9 @@ pub fn (mut p Parser) parse_generic_struct_inst_type(name string) table.Type {
 		}
 		gt_idx = p.table.add_placeholder_type(bs_name)
 		idx := p.table.register_type_symbol(table.TypeSymbol{
-			kind: .generic_struct_instance
+			kind: .generic_struct_inst
 			name: bs_name
-			info: table.GenericStructInstance{
+			info: table.GenericStructInst{
 				parent_idx: p.table.type_idxs[name]
 				generic_types: generic_types
 			}
diff --git a/vlib/v/table/atypes.v b/vlib/v/table/atypes.v
index f92be44b87..993afdc897 100644
--- a/vlib/v/table/atypes.v
+++ b/vlib/v/table/atypes.v
@@ -16,7 +16,7 @@ import strings
 pub type Type int
 
 pub type TypeInfo = Alias | Array | ArrayFixed | Enum | FnType | Interface | Map | MultiReturn |
-	Struct | GenericStructInstance | SumType
+	Struct | GenericStructInst | SumType
 
 pub enum Language {
 	v
@@ -321,7 +321,7 @@ pub enum Kind {
 	map
 	any
 	struct_
-	generic_struct_instance
+	generic_struct_inst
 	multi_return
 	sum_type
 	alias
@@ -623,9 +623,10 @@ pub mut:
 	generic_types []Type
 }
 
-pub struct GenericStructInstance {
+// instantiation of a generic struct
+pub struct GenericStructInst {
 pub mut:
-	parent_idx    int
+	parent_idx    int // idx of the base generic struct
 	generic_types []Type
 }