Reworks string storage... again. Back to unescaping on parse. But now we escape on raw print.

helpers.go

@@ -11,6 +11,7 @@ import (
 	"strconv"
 	"strings"
 	"syscall"
+	"unicode"
 )
 
 func AnythingToBool(e expression) expression {
@@ -137,7 +138,11 @@ func escapeString(s string) string {
 		case '\\':
 			out.WriteString("\\\\")
 		default:
-			out.WriteRune(c)
+			if !unicode.IsPrint(c) {
+				out.WriteString(fmt.Sprintf("\\0%o", c))
+			} else {
+				out.WriteRune(c)
+			}
 		}
 	}
 	return out.String()

interpreter.go

@@ -16,7 +16,9 @@ func eval(exp expression, en *env) (value expression) {
 	switch e := exp.(type) {
 	case symbol:
 		value = en.Find(e).vars[e]
-	case bool, number, string:
+	case string:
+		value = unescapeString(e)
+	case bool, number:
 		value = e
 	case exception:
 		if panicOnException {

main.go

@@ -47,7 +47,7 @@ func String(v expression, rawString bool) string {
 		return "(" + strings.Join(l, " ") + ")"
 	case string:
 		if rawString {
-			return fmt.Sprintf("\"%s\"", v)
+			return fmt.Sprintf("\"%s\"", escapeString(v))
 		}
 		return unescapeString(v)
 	case exception: