Reworks how various types print to provide better output/feedback from the system

lib.go

@@ -26,9 +26,9 @@ import (
 )
 
 var stdLibrary = vars{
-	"stdin": &IOHandle{os.Stdin, true},
-	"stdout": &IOHandle{os.Stdout, true},
-	"stderr": &IOHandle{os.Stderr, true},
+	"stdin": &IOHandle{os.Stdin, true, "file (read-only)"},
+	"stdout": &IOHandle{os.Stdout, true, "file (write-only)"},
+	"stderr": &IOHandle{os.Stderr, true, "file (write-only)"},
 	"PI": number(math.Pi),
 	"E":  number(math.E),
 	"sys-args": func(a ...expression) expression {
@@ -508,7 +508,7 @@ var stdLibrary = vars{
 		if len(a) > 0 {
       b.WriteString(String(a[0], false))
 		}
-		obj := &IOHandle{&b, true}
+		obj := &IOHandle{&b, true, "string-buf"}
 		openFiles = append(openFiles, obj)
 		return obj
 	},
@@ -1399,7 +1399,7 @@ var stdLibrary = vars{
 		if err != nil {
 			return exception("'file-create-temp' was unable to create the requested temporary file: " + err.Error())
 		}
-		obj := &IOHandle{f, true}
+		obj := &IOHandle{f, true, "file (write-only)"}
 		openFiles = append(openFiles, obj)
 		return obj
 	},
@@ -1468,7 +1468,7 @@ var stdLibrary = vars{
 		if err != nil {
 			return exception("'file-create' encountered an error: " + err.Error())
 		}
-		obj := &IOHandle{f, true}
+		obj := &IOHandle{f, true, "file (write-only)"}
 		openFiles = append(openFiles, obj)
 		return obj
 	},
@@ -1481,7 +1481,7 @@ var stdLibrary = vars{
 			if err != nil {
 				return false
 			}
-			obj := &IOHandle{f, true}
+			obj := &IOHandle{f, true, "file (read-only)"}
 			openFiles = append(openFiles, obj)
 			return obj
 		}
@@ -1503,7 +1503,7 @@ var stdLibrary = vars{
 			if err != nil {
 				return exception("'file-write' could not open the given filepath")
 			}
-			obj := &IOHandle{f, true}
+			obj := &IOHandle{f, true, "file (write-only)"}
 			openFiles = append(openFiles, obj)
 			return obj
 		}
@@ -1768,9 +1768,9 @@ var stdLibrary = vars{
 		// based on the tls value use tls or not, same with the timeout value for adding a timeout
 		var handle *IOHandle
 		if usetls {
-			handle = &IOHandle{tlsconn, true}
+			handle = &IOHandle{tlsconn, true, "net-conn (tls)"}
 		} else {
-			handle = &IOHandle{&conn, true}
+			handle = &IOHandle{&conn, true, "net-conn"}
 		}
 		openFiles = append(openFiles, handle)
 		return handle

main.go

@@ -59,6 +59,21 @@ func String(v expression, quoteString bool) string {
 		return "#f"
 	case number:
 		return strconv.FormatFloat(float64(v), 'f', -1, 64)
+	case proc:
+		var b strings.Builder
+		b.WriteString("(lambda ")
+		b.WriteString(String(v.params, true))
+		b.WriteRune(' ')
+		body := String(v.body, true)
+		if strings.HasPrefix(body, "(begin ") {
+			body = body[7:]
+		}
+		b.WriteString(body)
+		return b.String()
+	case func(...expression) expression:
+		return fmt.Sprint("Built-in: ", &v)
+	case *IOHandle:
+		return fmt.Sprintf("%+v", v)
 	default:
 		return fmt.Sprint(v)
 	}

parser.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"fmt"
 	"strconv"
 	"strings"
 )
@@ -10,6 +11,16 @@ type expression interface{}
 type IOHandle struct {
 	Obj  expression
 	Open bool
+	Kind string
+}
+
+func (i IOHandle) String() string {
+	state := "closed"
+	if i.Open {
+		state = "open"
+	}
+
+	return fmt.Sprintf("%s %s io-handle", state, i.Kind)
 }
 
 type number float64