rationalized context convertion to dict and string types

kern/dict-type.go

@@ -76,9 +76,11 @@ func (dict *DictType) toMultiLine(sb *strings.Builder, opt FmtOpt) {
 
 			sb.WriteString(nest)
 			if key, ok := name.(string); ok {
-				sb.WriteString(string('"') + key + string('"'))
+				sb.WriteByte('"')
+				sb.WriteString(key)
+				sb.WriteByte('"')
 			} else {
-				sb.WriteString(fmt.Sprintf("%v", name))
+				fmt.Fprintf(sb, "%v", name)
 			}
 			sb.WriteString(": ")
 			if f, ok := value.(Formatter); ok {
@@ -86,7 +88,7 @@ func (dict *DictType) toMultiLine(sb *strings.Builder, opt FmtOpt) {
 			} else if _, ok = value.(Functor); ok {
 				sb.WriteString("func(){}")
 			} else {
-				sb.WriteString(fmt.Sprintf("%v", value))
+				fmt.Fprintf(sb, "%v", value)
 			}
 		}
 		sb.WriteByte('\n')
@@ -110,9 +112,11 @@ func (dict *DictType) ToString(opt FmtOpt) string {
 				sb.WriteString(", ")
 			}
 			if s, ok := key.(string); ok {
-				sb.WriteString(string('"') + s + string('"'))
+				sb.WriteByte('"')
+				sb.WriteString(s)
+				sb.WriteByte('"')
 			} else {
-				sb.WriteString(fmt.Sprintf("%v", key))
+				fmt.Fprintf(&sb, "%v", key)
 			}
 			sb.WriteString(": ")
 			if formatter, ok := value.(Formatter); ok {
@@ -120,7 +124,7 @@ func (dict *DictType) ToString(opt FmtOpt) string {
 			} else if t, ok := value.(Term); ok {
 				sb.WriteString(t.String())
 			} else {
-				sb.WriteString(fmt.Sprintf("%#v", value))
+				fmt.Fprintf(&sb, "%#v", value)
 			}
 		}
 		sb.WriteByte('}')

kern/expr-context.go

@@ -28,4 +28,36 @@ type ExprContext interface {
 	Call(name string, args map[string]any) (result any, err error)
 	RegisterFuncInfo(info ExprFunc)
 	RegisterFunc(name string, f Functor, returnType string, param []ExprFuncParam) (funcInfo ExprFunc, err error)
+
+	ToDict() (dict *DictType)
+	ToString(opt FmtOpt) string
+}
+
+func ContextToDict(ctx ExprContext) (dict *DictType) {
+	var keys []string
+	// Variables
+	keys = ctx.EnumVars(nil)
+	vars := MakeDict()
+	for _, key := range keys {
+		value, _ := ctx.GetVar(key)
+		vars.SetItem(key, value)
+	}
+
+	// Functions
+	keys = ctx.EnumFuncs(func(name string) bool { return true })
+	funcs := MakeDict()
+	for _, key := range keys {
+		funcInfo, _ := ctx.GetFuncInfo(key)
+		funcs.SetItem(key, funcInfo)
+	}
+
+	dict = MakeDict()
+	dict.SetItem("vars", vars)
+	dict.SetItem("funcs", funcs)
+	return
+}
+
+func ContextToString(ctx ExprContext, opt FmtOpt) string {
+	dict := ctx.ToDict()
+	return dict.ToString(opt)
 }