moved scanner sources to package 'scan'

scan/term-constructor-registry.go

@@ -0,0 +1,27 @@
+// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
+// All rights reserved.
+
+// term-constructor-registry.go
+package scan
+
+const initialRegistryCapacity = 10
+
+type termContructor func(tk *Token) *Term
+
+var constructorRegistry map[Symbol]termContructor = nil
+
+func RegisterTermConstructor(sym Symbol, constructor termContructor) {
+	if constructorRegistry == nil {
+		constructorRegistry = make(map[Symbol]termContructor, initialRegistryCapacity)
+	}
+	constructorRegistry[sym] = constructor
+}
+
+func NewTerm(tk *Token) (inst *Term) {
+	if constructorRegistry != nil {
+		if construct, exists := constructorRegistry[tk.Sym]; exists {
+			inst = construct(tk)
+		}
+	}
+	return
+}