From b9d2afce749539b646e9e3f668f751da4e0e39a3 Mon Sep 17 00:00:00 2001
From: Jordan Orelli <jordanorelli@gmail.com>
Date: Tue, 30 Oct 2012 19:00:01 -0400
Subject: [PATCH] fixed quoting behavior

previously it was impossible to do the following:

    (define dave (quote (x y z)))
    dave

the interpreter would incorrectly try to evaluate the (x y z), because
there was no quote level being recorded, and it was seen as being the
same as a regular sexp.
---
 proc.go    |  2 +-
 skeam.go   | 18 ++++++++++++++++--
 special.go | 12 +++++++++++-
 3 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/proc.go b/proc.go
index abef4cd..bd25e8e 100644
--- a/proc.go
+++ b/proc.go
@@ -107,7 +107,7 @@ func length(vals []interface{}) (interface{}, error) {
 	return len(x), nil
 }
 
-func list(vals []interface{}) (interface{}, error) {
+func lst(vals []interface{}) (interface{}, error) {
 	return sexp(vals), nil
 }
 
diff --git a/skeam.go b/skeam.go
index 0d9267f..3126713 100644
--- a/skeam.go
+++ b/skeam.go
@@ -8,6 +8,7 @@ import (
 	"os"
 	"reflect"
 	"strconv"
+	"strings"
 )
 
 var DEBUG = false
@@ -15,7 +16,20 @@ var DEBUG = false
 type sexp []interface{}
 
 func (s sexp) String() string {
-	return "(" + fmt.Sprint(s...) + ")"
+	parts := make([]string, len(s))
+	for i, _ := range s {
+		parts[i] = fmt.Sprint(s[i])
+	}
+	return "(" + strings.Join(parts, " ") + ")"
+}
+
+type list struct {
+	sexp
+	quotelevel int
+}
+
+func (l list) String() string {
+	return l.sexp.String()
 }
 
 type symbol string
@@ -39,7 +53,7 @@ var universe = &environment{map[symbol]interface{}{
 	"car":     builtin(car),
 	"cdr":     builtin(cdr),
 	"length":  builtin(length),
-	"list":    builtin(list),
+	"list":    builtin(lst),
 	"list?":   builtin(islist),
 	"not":     builtin(not),
 	"null?":   builtin(isnull),
diff --git a/special.go b/special.go
index f88a2a7..eac1898 100644
--- a/special.go
+++ b/special.go
@@ -75,7 +75,17 @@ func quote(_ *environment, args ...interface{}) (interface{}, error) {
 		return nil, err
 	}
 
-	return args[0], nil
+	switch t := args[0].(type) {
+	case list:
+		fmt.Println("got a list...")
+		t.quotelevel++
+		return t, nil
+	case sexp:
+		return list{t, 1}, nil
+	default:
+		return t, nil
+	}
+	panic("not reached")
 }
 
 // turns an arbitrary lisp value into a boolean.  Apparently the sematics of