From 09a6d92c08d30e75eafd0f46027e1a583b44adfd Mon Sep 17 00:00:00 2001
From: Sameer Rahmani <lxsameer@gnu.org>
Date: Thu, 14 Jan 2021 18:17:38 +0000
Subject: [PATCH] Replace Tre/False types with a Bool type

---
 bootstrap/pkg/ast/ast.go                 |  3 +-
 bootstrap/pkg/core/{false.go => bool.go} | 38 +++++++++++++------
 bootstrap/pkg/core/eval.go               | 10 ++---
 bootstrap/pkg/core/true.go               | 48 ------------------------
 4 files changed, 33 insertions(+), 66 deletions(-)
 rename bootstrap/pkg/core/{false.go => bool.go} (59%)
 delete mode 100644 bootstrap/pkg/core/true.go

diff --git a/bootstrap/pkg/ast/ast.go b/bootstrap/pkg/ast/ast.go
index 189e73c..cacfda4 100644
--- a/bootstrap/pkg/ast/ast.go
+++ b/bootstrap/pkg/ast/ast.go
@@ -25,8 +25,7 @@ type NodeType int
 const (
 	Nil NodeType = iota
 	Nothing
-	True
-	False
+	Bool
 	Instruction
 	Symbol
 	Keyword
diff --git a/bootstrap/pkg/core/false.go b/bootstrap/pkg/core/bool.go
similarity index 59%
rename from bootstrap/pkg/core/false.go
rename to bootstrap/pkg/core/bool.go
index 1b3046b..670f0ed 100644
--- a/bootstrap/pkg/core/false.go
+++ b/bootstrap/pkg/core/bool.go
@@ -23,28 +23,44 @@ import (
 	"serene-lang.org/bootstrap/pkg/hash"
 )
 
-type False struct {
+type Bool struct {
 	Node
 	ExecutionScope
+	value bool
 }
 
-func (f *False) GetType() ast.NodeType {
-	return ast.False
+func (t *Bool) GetType() ast.NodeType {
+	return ast.Bool
 }
 
-func (f *False) String() string {
+func (t *Bool) String() string {
+	if t.value {
+		return "true"
+	}
 	return "false"
 }
 
-func (f *False) ToDebugStr() string {
-	return "false"
+func (t *Bool) ToDebugStr() string {
+	return t.String()
 }
 
-func (f *False) Hash() uint32 {
-	bytes := []byte("false")
-	return hash.Of(append([]byte{byte(ast.False)}, bytes...))
+func (t *Bool) Hash() uint32 {
+	bytes := []byte(t.String())
+	return hash.Of(append([]byte{byte(ast.Bool)}, bytes...))
 }
 
-func MakeFalse(n Node) *False {
-	return &False{Node: n}
+func (t *Bool) isTrue() bool {
+	return t.value
+}
+
+func (t *Bool) isFalse() bool {
+	return !t.value
+}
+
+func MakeTrue(n Node) *Bool {
+	return &Bool{Node: n, value: true}
+}
+
+func MakeFalse(n Node) *Bool {
+	return &Bool{Node: n, value: false}
 }
diff --git a/bootstrap/pkg/core/eval.go b/bootstrap/pkg/core/eval.go
index 4a94df7..a855348 100644
--- a/bootstrap/pkg/core/eval.go
+++ b/bootstrap/pkg/core/eval.go
@@ -451,13 +451,13 @@ tco:
 					return nil, err
 				}
 
-				if result != ast.False && result != ast.Nil {
-					// Truthy clause
-					exprs = append([]IExpr{args.Rest().First()}, restOfExprs(exprs, i)...)
-				} else {
-
+				if (result == ast.Bool && pred.(*Bool).isFalse()) || result == ast.Nil {
 					// Falsy clause
 					exprs = append([]IExpr{args.Rest().Rest().First()}, restOfExprs(exprs, i)...)
+				} else {
+					// Truthy clause
+					exprs = append([]IExpr{args.Rest().First()}, restOfExprs(exprs, i)...)
+
 				}
 				i = 0
 				goto body // rewrite
diff --git a/bootstrap/pkg/core/true.go b/bootstrap/pkg/core/true.go
deleted file mode 100644
index e05416d..0000000
--- a/bootstrap/pkg/core/true.go
+++ /dev/null
@@ -1,48 +0,0 @@
-/*
- Serene --- Yet an other Lisp
-
-Copyright (c) 2020  Sameer Rahmani <lxsameer@gnu.org>
-
-This program is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation, either version 2 of the License.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-package core
-
-import (
-	"serene-lang.org/bootstrap/pkg/ast"
-	"serene-lang.org/bootstrap/pkg/hash"
-)
-
-type True struct {
-	Node
-	ExecutionScope
-}
-
-func (t *True) GetType() ast.NodeType {
-	return ast.True
-}
-
-func (t *True) String() string {
-	return "true"
-}
-
-func (t *True) ToDebugStr() string {
-	return "true"
-}
-func (t *True) Hash() uint32 {
-	bytes := []byte("true")
-	return hash.Of(append([]byte{byte(ast.True)}, bytes...))
-}
-func MakeTrue(n Node) *True {
-	return &True{Node: n}
-}