From 2061394ad7d35ec1c8af32d1be58065ca9d3490c Mon Sep 17 00:00:00 2001
From: joe-conigliaro <joe-conigliaro@users.noreply.github.com>
Date: Sun, 5 Jan 2020 03:57:25 +1100
Subject: [PATCH] v: initial impl of new type sys w/ pointer & placeholder
 support (#3323)

---
 vlib/v/ast/ast.v          |  22 ++-
 vlib/v/gen/cgen.v         |  20 +--
 vlib/v/gen/jsgen.v        |  10 +-
 vlib/v/gen/x64/gen.v      |  12 +-
 vlib/v/parser/fn.v        |  40 ++---
 vlib/v/parser/parser.v    | 279 +++++++++++++++++++++++---------
 vlib/v/table/table.v      | 125 +++++++++++++--
 vlib/v/types/types.v      | 327 +++++++++++++++++++++++++++++++++-----
 vlib/v/types/types_test.v |   5 +
 9 files changed, 667 insertions(+), 173 deletions(-)
 create mode 100644 vlib/v/types/types_test.v

diff --git a/vlib/v/ast/ast.v b/vlib/v/ast/ast.v
index ed4e047cc3..8d94262f7a 100644
--- a/vlib/v/ast/ast.v
+++ b/vlib/v/ast/ast.v
@@ -17,7 +17,7 @@ ForStmt | StructDecl
 pub struct ExprStmt {
 pub:
 	expr Expr
-	typ  types.Type
+	ti   types.TypeIdent
 }
 
 pub struct IntegerLiteral {
@@ -59,7 +59,7 @@ pub:
 pub struct Field {
 pub:
 	name string
-	typ  types.Type
+	ti   types.TypeIdent
 }
 
 pub struct StructDecl {
@@ -71,7 +71,8 @@ pub:
 
 pub struct StructInit {
 pub:
-	typ    types.Type
+	ti   types.TypeIdent
+	// typ    types.Type
 	fields []string
 	exprs  []Expr
 }
@@ -86,7 +87,8 @@ pub:
 
 pub struct Arg {
 pub:
-	typ  types.Type
+	ti   types.TypeIdent
+	// typ  types.Type
 	name string
 }
 
@@ -94,7 +96,8 @@ pub struct FnDecl {
 pub:
 	name   string
 	stmts  []Stmt
-	typ    types.Type
+	ti   types.TypeIdent
+	// typ   types.Type
 	args   []Arg
 	is_pub bool
 	receiver Field
@@ -133,7 +136,8 @@ pub struct VarDecl {
 pub:
 	name string
 	expr Expr
-	typ  types.Type
+	ti   types.TypeIdent
+	// typ  types.Type
 }
 
 pub struct File {
@@ -174,7 +178,8 @@ pub:
 	cond       Expr
 	stmts      []Stmt
 	else_stmts []Stmt
-	typ        types.Type
+	ti         types.TypeIdent
+	// typ  types.Type
 	left       Expr // `a` in `a := if ...`
 }
 
@@ -200,7 +205,8 @@ pub:
 pub struct ArrayInit {
 pub:
 	exprs []Expr
-	typ   types.Type
+	ti    types.TypeIdent
+	// typ   types.Type
 }
 
 // string representaiton of expr
diff --git a/vlib/v/gen/cgen.v b/vlib/v/gen/cgen.v
index 924390474e..ea8c9c8e2d 100644
--- a/vlib/v/gen/cgen.v
+++ b/vlib/v/gen/cgen.v
@@ -53,12 +53,12 @@ fn (g mut Gen) stmt(node ast.Stmt) {
 				g.write('int ${it.name}(')
 			}
 			else {
-				g.write('$it.typ.name ${it.name}(')
-				g.definitions.write('$it.typ.name ${it.name}(')
+				g.write('$it.ti.type_name ${it.name}(')
+				g.definitions.write('$it.ti.type_name ${it.name}(')
 			}
 			for arg in it.args {
-				g.write(arg.typ.name + ' ' + arg.name)
-				g.definitions.write(arg.typ.name + ' ' + arg.name)
+				g.write(arg.ti.type_name + ' ' + arg.name)
+				g.definitions.write(arg.ti.type_name + ' ' + arg.name)
 			}
 			g.writeln(') { ')
 			if !is_main {
@@ -78,7 +78,7 @@ fn (g mut Gen) stmt(node ast.Stmt) {
 			g.writeln(';')
 		}
 		ast.VarDecl {
-			g.write('$it.typ.name $it.name = ')
+			g.write('$it.ti.type_name $it.name = ')
 			g.expr(it.expr)
 			g.writeln(';')
 		}
@@ -98,7 +98,7 @@ fn (g mut Gen) stmt(node ast.Stmt) {
 		ast.StructDecl {
 			g.writeln('typedef struct {')
 			for field in it.fields {
-				g.writeln('\t$field.typ.name $field.name;')
+				g.writeln('\t$field.ti.type_name $field.name;')
 			}
 			g.writeln('} $it.name;')
 		}
@@ -154,7 +154,7 @@ fn (g mut Gen) expr(node ast.Expr) {
 		}
 		// `user := User{name: 'Bob'}`
 		ast.StructInit {
-			g.writeln('($it.typ.name){')
+			g.writeln('($it.ti.type_name){')
 			for i, field in it.fields {
 				g.write('\t.$field = ')
 				g.expr(it.exprs[i])
@@ -173,7 +173,7 @@ fn (g mut Gen) expr(node ast.Expr) {
 			g.write(')')
 		}
 		ast.ArrayInit {
-			g.writeln('new_array_from_c_array($it.exprs.len, $it.exprs.len, sizeof($it.typ.name), {\t')
+			g.writeln('new_array_from_c_array($it.exprs.len, $it.exprs.len, sizeof($it.ti.type_name), {\t')
 			for expr in it.exprs {
 				g.expr(expr)
 				g.write(', ')
@@ -200,7 +200,7 @@ fn (g mut Gen) expr(node ast.Expr) {
 			// If expression? Assign the value to a temp var.
 			// Previously ?: was used, but it's too unreliable.
 			mut tmp := ''
-			if it.typ.idx != types.void_type.idx {
+			if it.ti.type_kind != ._void {
 				tmp = g.table.new_tmp_var()
 				// g.writeln('$it.typ.name $tmp;')
 			}
@@ -209,7 +209,7 @@ fn (g mut Gen) expr(node ast.Expr) {
 			g.writeln(') {')
 			for i, stmt in it.stmts {
 				// Assign ret value
-				if i == it.stmts.len - 1 && it.typ.idx != types.void_type.idx {
+				if i == it.stmts.len - 1 && it.ti.type_kind != ._void {
 					// g.writeln('$tmp =')
 					println(1)
 				}
diff --git a/vlib/v/gen/jsgen.v b/vlib/v/gen/jsgen.v
index dd816e290f..4873ac66cd 100644
--- a/vlib/v/gen/jsgen.v
+++ b/vlib/v/gen/jsgen.v
@@ -40,9 +40,9 @@ fn (g mut JsGen) stmt(node ast.Stmt) {
 			g.writeln(';')
 		}
 		ast.FnDecl {
-			g.write('/** @return { $it.typ.name } **/\nfunction ${it.name}(')
+			g.write('/** @return { $it.ti.type_name } **/\nfunction ${it.name}(')
 			for arg in it.args {
-				g.write(' /** @type { arg.typ.name } **/ $arg.name')
+				g.write(' /** @type { arg.ti.type_name } **/ $arg.name')
 			}
 			g.writeln(') { ')
 			for stmt in it.stmts {
@@ -56,7 +56,7 @@ fn (g mut JsGen) stmt(node ast.Stmt) {
 			g.writeln(';')
 		}
 		ast.VarDecl {
-			g.write('var /* $it.typ.name */ $it.name = ')
+			g.write('var /* $it.ti.type_name */ $it.name = ')
 			g.expr(it.expr)
 			g.writeln(';')
 		}
@@ -72,7 +72,7 @@ fn (g mut JsGen) stmt(node ast.Stmt) {
 		ast.StructDecl {
 			// g.writeln('typedef struct {')
 			// for field in it.fields {
-			// g.writeln('\t$field.typ.name $field.name;')
+			// g.writeln('\t$field.ti.type_name $field.name;')
 			// }
 			g.writeln('var $it.name = function() {};')
 		}
@@ -115,7 +115,7 @@ fn (g mut JsGen) expr(node ast.Expr) {
 		}
 		// `user := User{name: 'Bob'}`
 		ast.StructInit {
-			g.writeln('/*$it.typ.name*/{')
+			g.writeln('/*$it.ti.type_name*/{')
 			for i, field in it.fields {
 				g.write('\t$field : ')
 				g.expr(it.exprs[i])
diff --git a/vlib/v/gen/x64/gen.v b/vlib/v/gen/x64/gen.v
index fa4280c29e..569e741ff5 100644
--- a/vlib/v/gen/x64/gen.v
+++ b/vlib/v/gen/x64/gen.v
@@ -337,7 +337,7 @@ fn (g mut Gen) stmt(node ast.Stmt) {
 			g.writeln(';')
 		}
 		ast.VarDecl {
-			g.write('$it.typ.name $it.name = ')
+			g.write('$it.ti.type_name $it.name = ')
 			g.expr(it.expr)
 			g.writeln(';')
 		}
@@ -354,7 +354,7 @@ fn (g mut Gen) stmt(node ast.Stmt) {
 		ast.StructDecl {
 			g.writeln('typedef struct {')
 			for field in it.fields {
-				g.writeln('\t$field.typ.name $field.name;')
+				g.writeln('\t$field.ti.type_name $field.name;')
 			}
 			g.writeln('} $it.name;')
 		}
@@ -394,13 +394,13 @@ fn (g mut Gen) expr(node ast.Expr) {
 			g.expr(it.left)
 			g.write(' $it.op.str() ')
 			g.expr(it.right)
-			// if typ.name != typ2.name {
-			// verror('bad types $typ.name $typ2.name')
+			// if ti.type_name != typ2.name {
+			// verror('bad types $ti.type_name $typ2.name')
 			// }
 		}
 		// `user := User{name: 'Bob'}`
 		ast.StructInit {
-			g.writeln('($it.typ.name){')
+			g.writeln('($it.ti.type_name){')
 			for i, field in it.fields {
 				g.write('\t.$field = ')
 				g.expr(it.exprs[i])
@@ -426,7 +426,7 @@ fn (g mut Gen) expr(node ast.Expr) {
 
 		}
 		ast.ArrayInit {
-			g.writeln('new_array_from_c_array($it.exprs.len, $it.exprs.len, sizeof($it.typ.name), {\t')
+			g.writeln('new_array_from_c_array($it.exprs.len, $it.exprs.len, sizeof($it.ti.type_name), {\t')
 			for expr in it.exprs {
 				g.expr(expr)
 				g.write(', ')
diff --git a/vlib/v/parser/fn.v b/vlib/v/parser/fn.v
index f935c360b2..12da266008 100644
--- a/vlib/v/parser/fn.v
+++ b/vlib/v/parser/fn.v
@@ -13,20 +13,20 @@ import (
 	os
 )
 
-pub fn (p mut Parser) call_expr() (ast.CallExpr,types.Type) {
+pub fn (p mut Parser) call_expr() (ast.CallExpr,types.TypeIdent) {
 	// println('got fn call')
 	tok := p.tok
 	fn_name := p.check_name()
 	p.check(.lpar)
 	mut is_unknown := false
 	mut args := []ast.Expr
-	mut return_type := types.void_type
+	mut return_ti := types.new_base_ti(._void, 0)
 	if f := p.table.find_fn(fn_name) {
-		return_type = f.return_type
+		return_ti = f.return_ti
 		for i, arg in f.args {
-			e,typ := p.expr(0)
-			if !types.check(arg.typ, typ) {
-				p.error('cannot use type `$typ.name` as type `$arg.typ.name` in argument to `$fn_name`')
+			e,ti := p.expr(0)
+			if !types.check(arg.ti, ti) {
+				p.error('cannot use type `$ti.type_name` as type `$arg.ti.type_name` in argument to `$fn_name`')
 			}
 			args << e
 			if i < f.args.len - 1 {
@@ -59,7 +59,7 @@ pub fn (p mut Parser) call_expr() (ast.CallExpr,types.Type) {
 	if is_unknown {
 		p.table.unknown_calls << node
 	}
-	return node,return_type
+	return node,return_ti
 }
 
 fn (p mut Parser) fn_decl() ast.FnDecl {
@@ -71,17 +71,17 @@ fn (p mut Parser) fn_decl() ast.FnDecl {
 	p.check(.key_fn)
 	// Receiver?
 	mut rec_name := ''
-	mut rec_type := types.void_type
+	mut rec_ti := types.new_base_ti(._void, 0)
 	if p.tok.kind == .lpar {
 		p.next()
 		rec_name = p.check_name()
 		if p.tok.kind == .key_mut {
 			p.next()
 		}
-		rec_type = p.parse_type()
+		rec_ti = p.parse_ti()
 		p.table.register_var(table.Var{
 			name: rec_name
-			typ: rec_type
+			ti: rec_ti
 		})
 		p.check(.rpar)
 	}
@@ -98,16 +98,16 @@ fn (p mut Parser) fn_decl() ast.FnDecl {
 			p.check(.comma)
 			arg_names << p.check_name()
 		}
-		typ := p.parse_type()
+		ti := p.parse_ti()
 		for arg_name in arg_names {
 			arg := table.Var{
 				name: arg_name
-				typ: typ
+				ti: ti
 			}
 			args << arg
 			p.table.register_var(arg)
 			ast_args << ast.Arg{
-				typ: typ
+				ti: ti
 				name: arg_name
 			}
 		}
@@ -117,26 +117,26 @@ fn (p mut Parser) fn_decl() ast.FnDecl {
 	}
 	p.check(.rpar)
 	// Return type
-	mut typ := types.void_type
-	if p.tok.kind == .name {
-		typ = p.parse_type()
-		p.return_type = typ
+	mut ti := types.new_base_ti(._void, 0)
+	if p.tok.kind in [.amp, .name] {
+		ti = p.parse_ti()
+		p.return_ti = ti
 	}
 	p.table.register_fn(table.Fn{
 		name: name
 		args: args
-		return_type: typ
+		return_ti: ti
 	})
 	stmts := p.parse_block()
 	return ast.FnDecl{
 		name: name
 		stmts: stmts
-		typ: typ
+		ti: ti
 		args: ast_args
 		is_pub: is_pub
 		receiver: ast.Field{
 			name: rec_name
-			typ: rec_type
+			ti: rec_ti
 		}
 	}
 }
diff --git a/vlib/v/parser/parser.v b/vlib/v/parser/parser.v
index e06c2cd1eb..471ddec3d2 100644
--- a/vlib/v/parser/parser.v
+++ b/vlib/v/parser/parser.v
@@ -21,7 +21,7 @@ mut:
 	peek_tok    token.Token
 	// vars []string
 	table       &table.Table
-	return_type types.Type
+	return_ti   types.TypeIdent
 	is_c        bool
 }
 
@@ -35,6 +35,126 @@ pub fn parse_stmt(text string, table &table.Table) ast.Stmt {
 	return p.stmt()
 }
 
+pub fn (p mut Parser) parse_ti() types.TypeIdent {
+	defer {
+		p.next()
+	}
+	mut nr_muls := 0
+	if p.tok.kind == .amp {
+		p.check(.amp)
+		nr_muls = 1
+	}
+	name := p.tok.lit
+	if nr_muls > 0 {
+		println('## POINTER: $name')
+	}
+	match name {
+		'voidptr' {
+			return types.new_base_ti(._voidptr, nr_muls)
+		}
+		'byteptr' {
+			return types.new_base_ti(._byteptr, nr_muls)
+		}
+		'charptr' {
+			return types.new_base_ti(._charptr, nr_muls)
+		}
+		'164' {
+			return types.new_base_ti(._i16, nr_muls)
+		}
+		'int' {
+			return types.new_base_ti(._int, nr_muls)
+		}
+		'i64' {
+			return types.new_base_ti(._i64, nr_muls)
+		}
+		'byte' {
+			return types.new_base_ti(._byte, nr_muls)
+		}
+		'u16' {
+			return types.new_base_ti(._u16, nr_muls)
+		}
+		'u32' {
+			return types.new_base_ti(._u32, nr_muls)
+		}
+		'u64' {
+			return types.new_base_ti(._u64, nr_muls)
+		}
+		'f32' {
+			return types.new_base_ti(._f32, nr_muls)
+		}
+		'f64' {
+			return types.new_base_ti(._f64, nr_muls)
+		}
+		'string' {
+			return types.new_base_ti(._string, nr_muls)
+		}
+		'char' {
+			return types.new_base_ti(._char, nr_muls)
+		}
+		'bool' {
+			return types.new_base_ti(._bool, nr_muls)
+		}
+		else {
+			// array
+			if p.tok.kind == .lsbr {
+				p.check(.lsbr)
+				// fixed array
+				if p.tok.kind == .number {
+					fixed_size := p.tok.lit.int()
+					p.check(.rsbr)
+					elem_ti := p.parse_ti()
+					array_fixed_type := types.ArrayFixed{
+						name: 'array_fixed_$elem_ti.type_name'
+						size: fixed_size
+						elem_type_idx: elem_ti.type_idx
+					}
+					idx := p.table.find_or_register_array_fixed(array_fixed_type)
+					return types.new_ti(._array_fixed, array_fixed_type.name, idx, nr_muls)
+				}
+				p.check(.rsbr)
+				// array
+				elem_ti := p.parse_ti()
+				array_type := types.Array{
+					name: 'array_$elem_ti.type_name'
+					elem_type_idx: elem_ti.type_idx
+				}
+				idx := p.table.find_or_register_array(array_type)
+				return types.new_ti(._array, array_type.name, idx, nr_muls)
+			}
+			// map
+			else if name == 'map' {
+				p.next()
+				p.check(.lsbr)
+				key_ti := p.parse_ti()
+				p.check(.rsbr)
+				value_ti := p.parse_ti()
+				map_type := types.Map{
+					name: 'map_${key_ti.type_name}_${value_ti.type_name}'
+					key_type_idx: key_ti.type_idx,
+					value_type_idx: value_ti.type_idx
+				}
+				idx := p.table.find_or_register_map(map_type)
+				return types.new_ti(._map, map_type.name, idx, nr_muls)
+			} else {
+				// struct / enum
+				mut idx := p.table.find_type_idx(name)
+				// add placeholder
+				if idx == 0 {
+					idx = p.table.add_placeholder_type(name)
+				}
+				return types.new_ti(._placeholder, name, idx, nr_muls)
+			}
+
+			// typ := p.table.types[p.tok.lit]
+			// if isnil(typ.name.str) || typ.name == '' {
+			// 	p.error('undefined type `$p.tok.lit`')
+			// }
+			// println('RET Typ $typ.name')
+			// typ
+		}
+	}
+}
+
 pub fn parse_file(path string, table &table.Table) ast.File {
 	println('parse file "$path"')
 	text := os.read_file(path) or {
@@ -74,16 +194,16 @@ pub fn parse_files(paths []string, table &table.Table) []ast.File {
 }
 
 // former get_type()
-pub fn (p mut Parser) parse_type() types.Type {
-	typ := p.table.find_type(p.tok.lit) or {
-		// typ := p.table.types[p.tok.lit]
-		// if isnil(typ.name.str) || typ.name == '' {
-		p.error('undefined type `$p.tok.lit`')
-		exit(0)
-	}
-	p.next()
-	return typ
-}
+// pub fn (p mut Parser) parse_ti() types.Type {
+// 	typ := p.table.find_type(p.tok.lit) or {
+// 		// typ := p.table.types[p.tok.lit]
+// 		// if isnil(typ.name.str) || typ.name == '' {
+// 		p.error('undefined type `$p.tok.lit`')
+// 		exit(0)
+// 	}
+// 	p.next()
+// 	return typ
+// }
 
 pub fn (p mut Parser) read_first_token() {
 	// need to call next() twice to get peek token and current token
@@ -157,7 +277,7 @@ pub fn (p mut Parser) stmt() ast.Stmt {
 					p.error('wrong pub keyword usage')
 					return ast.Stmt{}
 				}
-	}
+			}
 			// .key_const {
 			// return p.const_decl()
 			// }
@@ -184,10 +304,10 @@ pub fn (p mut Parser) stmt() ast.Stmt {
 			return p.for_statement()
 		}
 		else {
-			expr,typ := p.expr(0)
+			expr,ti := p.expr(0)
 			return ast.ExprStmt{
 				expr: expr
-				typ: typ
+				ti: ti
 			}
 		}
 	}
@@ -233,11 +353,12 @@ pub fn (p &Parser) warn(s string) {
 }
 
 // Implementation of Pratt Precedence
-pub fn (p mut Parser) expr(rbp int) (ast.Expr,types.Type) {
+pub fn (p mut Parser) expr(rbp int) (ast.Expr,types.TypeIdent) {
 	// println('expr at ' + p.tok.str())
 	// null denotation (prefix)
 	mut node := ast.Expr{}
-	mut typ := types.void_type
+	// mut typ := types.void_type
+	mut ti := types.new_base_ti(._void, 0)
 	match p.tok.kind {
 		.name {
 			/*
@@ -254,13 +375,13 @@ pub fn (p mut Parser) expr(rbp int) (ast.Expr,types.Type) {
 			}
 			// fn call
 			if p.peek_tok.kind == .lpar {
-				x,typ2 := p.call_expr() // TODO `node,typ :=` should work
+				x,ti2 := p.call_expr() // TODO `node,typ :=` should work
 				node = x
-				typ = typ2
+				ti = ti2
 			}
 			// struct init
 			else if p.peek_tok.kind == .lcbr {
-				typ = p.parse_type()
+				ti = p.parse_ti()
 				// println('sturct init typ=$typ.name')
 				p.check(.lcbr)
 				mut field_names := []string
@@ -275,7 +396,7 @@ pub fn (p mut Parser) expr(rbp int) (ast.Expr,types.Type) {
 					exprs << expr
 				}
 				node = ast.StructInit{
-					typ: typ
+					ti: ti
 					exprs: exprs
 					fields: field_names
 				}
@@ -290,46 +411,46 @@ pub fn (p mut Parser) expr(rbp int) (ast.Expr,types.Type) {
 					p.error('unknown variable `$p.tok.lit`')
 					exit(0)
 				}
-				typ = var.typ
+				ti = var.ti
 				// ///typ = types.int_type
 				p.next()
 			}
 		}
 		.lsbr {
-			node,typ = p.array_init()
+			node,ti = p.array_init()
 		}
 		.key_true, .key_false {
 			node = ast.BoolLiteral{
 				val: p.tok.kind == .key_true
 			}
-			typ = types.bool_type
+			ti = types.new_base_ti(._bool, 0)
 			p.next()
 		}
 		.str {
-			node,typ = p.parse_string_literal()
+			node,ti = p.parse_string_literal()
 		}
 		.number {
-			node,typ = p.parse_number_literal()
+			node,ti = p.parse_number_literal()
 		}
 		.key_if {
-			node,typ = p.if_expr()
+			node,ti = p.if_expr()
 		}
 		.lpar {
 			p.check(.lpar)
 			p.next()
-			node,typ = p.expr(token.lowest_prec)
+			node,ti = p.expr(token.lowest_prec)
 			p.check(.rpar)
 		}
 		else {
 			if p.tok.is_unary() {
 				pt := p.tok
 				p.next()
-				expr,t2 := p.expr(token.lowest_prec)
+				expr,ti2 := p.expr(token.lowest_prec)
 				node = ast.UnaryExpr{
 					left: expr
 					op: pt.kind
 				}
-				typ = t2
+				ti = ti2
 			}
 			else {
 				p.error('expr(): unknown token ' + p.tok.str() + ' kind=$p.tok.kind')
@@ -340,30 +461,36 @@ pub fn (p mut Parser) expr(rbp int) (ast.Expr,types.Type) {
 	for rbp < p.tok.precedence() {
 		prev_tok := p.tok
 		p.next()
-		mut t2 := types.Type{}
+		// mut t2 := types.Type{}
+		mut ti2 := types.new_base_ti(._void, 0)
 		// left denotation (infix / postfix)
 		if prev_tok.is_right_assoc() && !p.tok.kind in [.plus, .minus] && // think of better way to handle this
 		!p.peek_tok.kind in [.number, .name] {
 			// supposed to be only unary, additive handled in left asssoc
 			mut expr := ast.Expr{}
-			expr,t2 = p.expr(prev_tok.precedence() - 1)
+			expr,ti2 = p.expr(prev_tok.precedence() - 1)
 			node = ast.BinaryExpr{
 				left: node
 				op: prev_tok.kind
 				right: expr
 			}
 			// println(t2.name + 'OOO')
-			if !types.check(&typ, &t2) {
+			if !types.check(&ti, &ti2) {
 				println('tok: $prev_tok.str()')
-				p.error('cannot convert `$t2.name` to `$typ.name`')
+				p.error('cannot convert `$ti2.type_name` to `$ti.type_name`')
 			}
 		}
 		else if prev_tok.is_left_assoc() {
 			// postfix `.`
 			if prev_tok.kind == .dot {
-				p.warn('dot prev_tok = $prev_tok.str() typ=$typ.name')
+				p.warn('dot prev_tok = $prev_tok.str() typ=$ti.type_name')
 				// p.next()
 				field := p.check_name()
+				if !ti.type_kind in  [._placeholder, ._struct] {
+					println('kind: $ti.str()')
+					p.error('cannot access field, `$ti.type_name` is not a struct')
+				}
+				typ := p.table.types[ti.type_idx] as types.Struct
 				mut ok := false
 				for f in typ.fields {
 					if f.name == field {
@@ -388,14 +515,15 @@ pub fn (p mut Parser) expr(rbp int) (ast.Expr,types.Type) {
 			}
 			else {
 				mut expr := ast.Expr{}
-				expr,t2 = p.expr(prev_tok.precedence() - 1)
+				expr,ti2 = p.expr(prev_tok.precedence() - 1)
 				if prev_tok.is_relational() {
-					typ = types.bool_type
+					// typ = types.bool_type
+					ti = types.new_base_ti(._bool, 0)
 				}
 				else {
-					typ = t2
+					ti = ti2
 				}
-				// println(t2.name + '222')
+				// println(ti2.type_name + '222')
 				node = ast.BinaryExpr{
 					left: node
 					op: prev_tok.kind
@@ -404,7 +532,7 @@ pub fn (p mut Parser) expr(rbp int) (ast.Expr,types.Type) {
 			}
 		}
 	}
-	return node,typ
+	return node,ti
 }
 
 [inline]
@@ -432,8 +560,9 @@ fn (p mut Parser) for_statement() ast.ForStmt {
 		}
 	}
 	// `for cond {`
-	cond,typ := p.expr(0)
-	if !types.check(types.bool_type, typ) {
+	cond,ti := p.expr(0)
+	// if !types.check(types.bool_type, ti) {
+	if ti.type_kind != ._bool {
 		p.error('non-bool used as for condition')
 	}
 	stmts := p.parse_block()
@@ -443,11 +572,12 @@ fn (p mut Parser) for_statement() ast.ForStmt {
 	}
 }
 
-fn (p mut Parser) if_expr() (ast.Expr,types.Type) {
+fn (p mut Parser) if_expr() (ast.Expr,types.TypeIdent) {
 	mut node := ast.Expr{}
 	p.check(.key_if)
 	cond,cond_type := p.expr(0)
-	if !types.check(types.bool_type, cond_type) {
+	// if !types.check(types.bool_type, cond_type) {
+	if cond_type.type_kind != ._bool {
 		p.error('non-bool used as if condition')
 	}
 	stmts := p.parse_block()
@@ -457,13 +587,14 @@ fn (p mut Parser) if_expr() (ast.Expr,types.Type) {
 		p.check(.key_else)
 		else_stmts = p.parse_block()
 	}
-	mut typ := types.void_type
+	// mut typ := types.void_type
+	mut ti := types.new_base_ti(._void, 0)
 	// mut left := ast.Expr{}
 	// If the last statement is an expression, return its type
 	match stmts[stmts.len - 1] {
 		ast.ExprStmt {
-			p.warn('if expr ret $it.typ.name')
-			typ = it.typ
+			p.warn('if expr ret $it.ti.type_name')
+			ti = it.ti
 			// return node,it.typ
 			// left =
 		}
@@ -473,35 +604,37 @@ fn (p mut Parser) if_expr() (ast.Expr,types.Type) {
 		cond: cond
 		stmts: stmts
 		else_stmts: else_stmts
-		typ: typ
+		ti: ti
 		// left: left
 		
 	}
-	return node,typ
+	return node,ti
 }
 
-fn (p mut Parser) parse_string_literal() (ast.Expr,types.Type) {
+fn (p mut Parser) parse_string_literal() (ast.Expr,types.TypeIdent) {
 	mut node := ast.Expr{}
 	node = ast.StringLiteral{
 		val: p.tok.lit
 	}
 	p.next()
-	return node,types.string_type
+	// return node,types.string_type
+	return node, types.new_base_ti(._string, 0)
 }
 
-fn (p mut Parser) array_init() (ast.Expr,types.Type) {
+fn (p mut Parser) array_init() (ast.Expr,types.TypeIdent) {
 	p.check(.lsbr)
-	mut val_type := types.void_type
+	// mut val_type := types.void_type
+	mut val_ti := types.new_base_ti(._void, 0)
 	mut exprs := []ast.Expr
 	mut i := 0
 	for p.tok.kind != .rsbr {
-		expr,typ := p.expr(0)
+		expr,ti := p.expr(0)
 		// The first element's type
 		if i == 0 {
-			val_type = typ
+			val_ti = ti
 		}
-		else if !types.check(val_type, typ) {
-			p.error('expected array element with type `$val_type.name`')
+		else if !types.check(val_ti, ti) {
+			p.error('expected array element with type `$val_ti.type_name`')
 		}
 		exprs << expr
 		i++
@@ -511,32 +644,32 @@ fn (p mut Parser) array_init() (ast.Expr,types.Type) {
 	}
 	mut node := ast.Expr{}
 	node = ast.ArrayInit{
-		typ: val_type
+		ti: val_ti
 		exprs: exprs
 	}
 	p.check(.rsbr)
-	return node,val_type
+	return node,val_ti
 }
 
-fn (p mut Parser) parse_number_literal() (ast.Expr,types.Type) {
+fn (p mut Parser) parse_number_literal() (ast.Expr,types.TypeIdent) {
 	lit := p.tok.lit
 	mut node := ast.Expr{}
-	mut typ := types.int_type
+	mut ti := types.new_base_ti(._int, 0)
 	if lit.contains('.') {
 		node = ast.FloatLiteral{
 			// val: lit.f64()
 			val: lit
 		}
-		typ = types.f64_type
+		ti = types.new_base_ti(._f64, 0)
 	}
 	else {
 		node = ast.IntegerLiteral{
 			val: lit.int()
 		}
-		typ = types.int_type
+		// ti = types.new_base_ti(._int, 0)
 	}
 	p.next()
-	return node,typ
+	return node,ti
 }
 
 fn (p mut Parser) module_decl() ast.Module {
@@ -569,18 +702,22 @@ fn (p mut Parser) struct_decl() ast.StructDecl {
 			p.check(.colon)
 		}
 		field_name := p.check_name()
-		typ := p.parse_type()
+		ti := p.parse_ti()
 		ast_fields << ast.Field{
 			name: field_name
-			typ: typ
+			ti: ti
 		}
 		fields << types.Field{
 			name: field_name
-			type_idx: typ.idx
+			type_idx: ti.type_idx
 		}
 	}
 	p.check(.rcbr)
-	p.table.register_type(types.Type{
+	if name in p.table.type_idxs {
+		println('placeholder exists: $name')
+	}
+	println('about to register: $name')
+	p.table.register_struct(types.Struct{
 		name: name
 		fields: fields
 	})
@@ -594,8 +731,8 @@ fn (p mut Parser) struct_decl() ast.StructDecl {
 fn (p mut Parser) return_stmt() ast.Return {
 	p.next()
 	expr,t := p.expr(0)
-	if !types.check(p.return_type, t) {
-		p.error('cannot use `$t.name` as type `$p.return_type.name` in return argument')
+	if !types.check(p.return_ti, t) {
+		p.error('cannot use `$t.type_name` as type `$p.return_ti.type_name` in return argument')
 	}
 	return ast.Return{
 		expr: expr
@@ -621,7 +758,7 @@ fn (p mut Parser) var_decl() ast.VarDecl {
 	}
 	p.table.register_var(table.Var{
 		name: name
-		typ: t
+		ti: t
 		is_mut: is_mut
 	})
 	// println(p.table.names)
@@ -630,7 +767,7 @@ fn (p mut Parser) var_decl() ast.VarDecl {
 		name: name
 		expr: expr // p.expr(token.lowest_prec)
 		
-		typ: t
+		ti: t
 	}
 }
 
diff --git a/vlib/v/table/table.v b/vlib/v/table/table.v
index fcdfd72e56..f901eae5b5 100644
--- a/vlib/v/table/table.v
+++ b/vlib/v/table/table.v
@@ -8,7 +8,9 @@ import (
 pub struct Table {
 	// struct_fields map[string][]string
 pub mut:
-	types         map[string]types.Type
+	// types         map[string]types.Type
+	types         []types.Type
+	type_idxs     map[string]int
 	local_vars    []Var
 	// fns Hashmap
 	fns           map[string]Fn
@@ -20,7 +22,7 @@ pub mut:
 pub struct Var {
 pub:
 	name   string
-	typ    types.Type
+	ti     types.TypeIdent
 	is_mut bool
 }
 
@@ -28,17 +30,23 @@ pub struct Fn {
 pub:
 	name        string
 	args        []Var
-	return_type types.Type
+	return_ti types.TypeIdent
 }
 
 pub fn new_table() &Table {
+	// mut t := &Table{}
+	// t.register_type(types.void_type)
+	// t.register_type(types.int_type)
+	// t.register_type(types.string_type)
+	// t.register_type(types.f64_type)
+	// t.register_type(types.bool_type)
+	// t.register_type(types.voidptr_type)
 	mut t := &Table{}
-	t.register_type(types.void_type)
-	t.register_type(types.int_type)
-	t.register_type(types.string_type)
-	t.register_type(types.f64_type)
-	t.register_type(types.bool_type)
-	t.register_type(types.voidptr_type)
+	// add dummy type at 0 so nothing can go there
+	// save index check, 0 will mean not found
+	t.types << types.Type{}
+	t.type_idxs['dymmy_type_at_idx_0'] = 0
+
 	return t
 }
 
@@ -109,19 +117,106 @@ pub fn (t mut Table) register_fn(new_fn Fn) {
 	t.fns[new_fn.name] = new_fn
 }
 
-pub fn (t mut Table) register_type(typ types.Type) {
-	t.types[typ.name] = typ
+pub fn (t mut Table) register_struct(typ types.Struct) int {
+	mut t2 := types.Type{}
+	// existing
+	existing_idx := t.type_idxs[typ.name]
+	if existing_idx > 0 {
+		ex_type := t.types[existing_idx]
+		match ex_type {
+			types.Placeholder {
+				// override placeholder
+				println('placeholder exists: $it.name overidding')
+				t2 = {typ| idx: existing_idx}
+				t.types[existing_idx] = t2
+				return existing_idx
+			}
+			else {}
+		}
+	}
+	// register
+	println('registering: $typ.name')
+	idx := t.types.len
+	t.type_idxs[typ.name] = idx
+	t2 = {typ| idx: idx}
+	t.types << t2
+
+	return idx
+}
+
+pub fn (t mut Table) find_or_register_map(typ types.Map) int {
+	// existing
+	existing_idx := t.type_idxs[typ.name]
+	if existing_idx > 0 {
+		return existing_idx
+	}
+	// register
+	idx := t.types.len
+	mut t2 := types.Type{}
+	t2 = {typ| idx: idx}
+	t.type_idxs[typ.name] = idx
+	t.types << t2
+	return idx
+}
+
+pub fn (t mut Table) find_or_register_array(typ types.Array) int {
+	// existing
+	existing_idx := t.type_idxs[typ.name]
+	if existing_idx > 0 {
+		return existing_idx
+	}
+	// register
+	idx := t.types.len
+	mut t2 := types.Type{}
+	t2 = {typ| idx: idx}
+	t.type_idxs[typ.name] = idx
+	t.types << t2
+	return idx
+}
+
+pub fn (t mut Table) find_or_register_array_fixed(typ types.ArrayFixed) int {
+	// existing
+	existing_idx := t.type_idxs[typ.name]
+	if existing_idx > 0 {
+		return existing_idx
+	}
+	// register
+	idx := t.types.len
+	mut t2 := types.Type{}
+	t2 = {typ| idx: idx}
+	t.type_idxs[typ.name] = idx
+	t.types << t2
+	return idx
+}
+
+[inline]
+pub fn (t &Table) find_type_idx(name string) int {
+	return t.type_idxs[name]
+}
+
+pub fn (t mut Table) add_placeholder_type(name string) int {
+	idx := t.types.len
+	t.type_idxs[name] = t.types.len
+	mut pt := types.Type{}
+	pt = types.Placeholder{
+		idx: idx
+		name: name
+	}
+	println('added placeholder: $name - $idx ')
+	t.types << pt
+	return idx
 }
 
 pub fn (t &Table) find_type(name string) ?types.Type {
-	typ := t.types[name]
-	if isnil(typ.name.str) || typ.name == '' {
-		return none
+	idx := t.type_idxs[name]
+	if idx > 0 {
+		return t.types[idx]
 	}
-	return typ
+	return none
 }
 
 pub fn (t mut Table) new_tmp_var() string {
 	t.tmp_cnt++
 	return 'tmp$t.tmp_cnt'
 }
+
diff --git a/vlib/v/types/types.v b/vlib/v/types/types.v
index 508179fb7f..29a0fef2c4 100644
--- a/vlib/v/types/types.v
+++ b/vlib/v/types/types.v
@@ -4,16 +4,208 @@
 module types
 
 pub enum Kind {
-	struct_
-	builtin
-	enum_
+	_placeholder,
+	_void,
+	_voidptr,
+	_charptr,
+	_byteptr,
+	_const,
+	_enum,
+	_struct,
+	_int,
+	_i8,
+	_i16,
+	_i64,
+	_byte,
+	_u16,
+	_u32,
+	_u64,
+	_f32,
+	_f64,
+	_string,
+	_char,
+	_bool,
+	_array,
+	_array_fixed,
+	_map,
+	_multi_return,
+	_variadic
 }
 
-pub struct Type {
+pub struct TypeIdent {
+pub:
+	type_idx  int
+	type_kind Kind
+	type_name string
+	nr_muls   int
+}
+
+[inline]
+pub fn new_ti(type_kind Kind, type_name string, type_idx int, nr_muls int) TypeIdent {
+    return TypeIdent{
+		type_idx: type_idx
+		type_kind: type_kind
+		type_name: type_name
+		nr_muls: nr_muls
+	}
+}
+
+[inline]
+pub fn new_base_ti(type_kind Kind, nr_muls int) TypeIdent {
+    return TypeIdent{
+		type_kind: type_kind
+		type_name: type_kind.str()
+		nr_muls: nr_muls
+	}
+}
+
+[inline]
+pub fn (ti &TypeIdent) is_ptr() bool {
+    return ti.nr_muls > 0
+}
+
+[inline]
+pub fn (ti &TypeIdent) is_int() bool {
+    return ti.type_kind in [._i8, ._i16, ._int, ._i64, ._byte, ._u16, ._u32, ._u64]
+}
+
+[inline]
+pub fn (ti &TypeIdent) is_float() bool {
+    return ti.type_kind in [._f32, ._f64]
+}
+
+[inline]
+pub fn (ti &TypeIdent) is_number() bool {
+    return ti.is_int() || ti.is_float()
+}
+
+pub fn (ti &TypeIdent) str() string {
+	return '$ti.type_kind.str() $ti.type_idx: $ti.type_name ($ti.nr_muls)'
+}
+
+pub fn check(got, expected &TypeIdent) bool {
+	if got.type_idx != expected.type_idx {
+		return false
+	}
+	return true
+}
+
+pub fn (t Kind) str() string {
+	t_str := match t {
+		._placeholder {
+			'placeholder'
+		}
+		._void  {
+			'void'
+		} 
+		._voidptr  {
+			'voidptr'
+		}
+		._charptr  {
+			'charptr'
+		}
+		._byteptr  {
+			'byteptr'
+		}
+		._const  {
+			'const'
+		}
+		._enum  {
+			'enum'
+		}
+		._struct  {
+			'struct'
+		}
+		._int  {
+			'int'
+		}
+		._i8  {
+			'i8'
+		}
+		._i16  {
+			'i16'
+		}
+		._i64  {
+			'i64'
+		}
+		._byte  {
+			'byte'
+		}
+		._u16  {
+			'u18'
+		}
+		._f32  {
+			'f32'
+		}
+		._f64  {
+			'f64'
+		}
+		._string  {
+			'string'
+		}
+		._char  {
+			'char'
+		}
+		._bool  {
+			'bool'
+		}
+		._array  {
+			'array'
+		}
+		._array_fixed  {
+			'array_fixed'
+		}
+		._map  {
+			'map'
+		}
+		._multi_return  {
+			'multi_return'
+		}
+		._variadic {
+			'variadic'
+		}
+		else {
+			'unknown'
+		}
+	}
+	return t_str
+}
+
+pub type Type = Placeholder | Void | Voidptr | Charptr | Byteptr | Const | Enum | Struct |
+	Int | Float | String | Char | Byte | Bool | Array | ArrayFixed | Map | MultiReturn | Variadic
+
+
+pub struct Placeholder {
+pub:
+	idx  int
+	name string
+	kind Kind
+}
+
+pub struct Void {}
+
+pub struct Voidptr {}
+
+pub struct Charptr {}
+
+pub struct Byteptr {}
+
+pub struct Const {
+pub:
+	idx  int
+	name string
+}
+
+pub struct Enum {
+pub:
+	idx  int
+	name string
+}
+
+pub struct Struct {
 pub:
-	name   string
 	idx    int
-	// kind Kind
+	name   string
 	fields []Field
 }
 
@@ -23,36 +215,95 @@ pub:
 	type_idx int
 }
 
-pub const (
-	void_type = Type{
-		name: 'void'
-		idx: 0
-	}
-	int_type = Type{
-		name: 'int'
-		idx: 1
-	}
-	string_type = Type{
-		name: 'string'
-		idx: 2
-	}
-	f64_type = Type{
-		name: 'f64'
-		idx: 3
-	}
-	bool_type = Type{
-		name: 'bool'
-		idx: 4
-	}
-	voidptr_type = Type{
-		name: 'voidptr'
-		idx: 5
-	}
-)
-
-pub fn check(got, expected &Type) bool {
-	if got.idx != expected.idx {
-		return false
-	}
-	return true
+pub struct Int {
+pub:
+	bit_size    u32
+	is_unsigned bool
 }
+
+pub struct Float {
+	bit_size u32
+}
+
+pub struct String {}
+
+pub struct Char {}
+
+pub struct Byte {}
+
+pub struct Bool {}
+
+pub struct Array {
+pub:
+	idx            int
+	name           string
+	elem_type_kind Kind
+	elem_type_idx  int
+	nr_dims        int
+}
+
+pub struct ArrayFixed {
+pub:
+	idx            int
+	name           string
+	elem_type_kind Kind
+	elem_type_idx  int
+	size           int
+}
+
+pub struct Map {
+pub:
+	idx             int
+	name            string
+	key_type_kind   Kind
+	key_type_idx    int 
+	value_type_kind Kind
+	value_type_idx  int
+}
+
+pub struct MultiReturn {
+pub:
+	elem_type_kinds []Kind
+	elem_type_idxs  []int
+}
+
+pub struct Variadic {
+pub:
+	elem_type_kind Kind
+	elem_type_idx  int
+}
+
+pub fn (t Void) str() string { return 'void' }
+pub fn (t Voidptr) str() string { return 'voidptr' }
+pub fn (t Charptr) str() string { return 'charptr' }
+pub fn (t Byteptr) str() string { return 'Byteptr' }
+pub fn (t Const) str() string { return t.name }
+pub fn (t Enum) str() string { return t.name }
+pub fn (t Struct) str() string { return t.name }
+pub fn (t Int) str() string { return if t.is_unsigned {'u$t.bit_size' } else { 'i$t.bit_size' } }
+pub fn (t Float) str() string { return 'f$t.bit_size' }
+pub fn (t String) str() string { return 'string' }
+pub fn (t Char) str() string { return 'char' }
+pub fn (t Byte) str() string { return 'byte' }
+pub fn (t Array) str() string { return t.name }
+pub fn (t ArrayFixed) str() string { return t.name }
+pub fn (t Map) str() string { return t.name }
+pub fn (t MultiReturn) str() string { return 'multi_return_$t.elem_type_kinds.str()' }
+pub fn (t Variadic) str() string { return 'variadic_$t.elem_type_kind.str()' }
+
+pub const (
+	void_type    = Void{}
+	voidptr_type = Voidptr{}
+	charptr_type = Charptr{}
+	byteptr_type = Byteptr{}
+	int_type     = Int{32, false}
+	i64_type     = Int{64, false}
+	byte_type    = Int{8, true}
+	u32_type     = Int{32, true}
+	u64_type     = Int{64, true}
+	f32_type     = Float{32}
+	f64_type     = Float{64}
+	string_type  = String{}
+	char_type    = Char{}
+	bool_type    = Bool{}
+)
diff --git a/vlib/v/types/types_test.v b/vlib/v/types/types_test.v
new file mode 100644
index 0000000000..93a62492b4
--- /dev/null
+++ b/vlib/v/types/types_test.v
@@ -0,0 +1,5 @@
+module types
+
+fn test_types() {
+
+}