inital commit

src/main/java/com/reliancy/rec/Slot.java

@@ -0,0 +1,60 @@
+package com.reliancy.rec;
+
+/**
+ * Slot is a definition of a value start with the name.
+ * We use it to define columns/fields of records. 
+ * It is also used as header of actual records.
+ */
+public class Slot extends Hdr {
+
+    public static interface Initializer{
+        Object getInitalValue(Slot s,Rec rec);
+    }
+    public static final Initializer DEFAULT_INITIALIZER=new Initializer(){
+        public Object getInitalValue(Slot s,Rec rec) {return s.getDefaultValue();}
+    };
+    int position;
+    Object defaultValue;
+    Initializer initValue;
+
+    public Slot(String name){
+        this(name,Object.class);
+    }
+    public Slot(String name,Class<?> type){
+        super(name,type);
+        this.position=-1;
+        this.initValue=DEFAULT_INITIALIZER;
+    }
+    public int getPosition() {
+        return position;
+    }
+    public void setPosition(int position) {
+        this.position = position;
+    }
+    public Object getDefaultValue() {
+        return defaultValue;
+    }
+    public void setDefaultValue(Object defaultValue) {
+        this.defaultValue = defaultValue;
+    }
+    public Initializer getInitValue() {
+        return initValue;
+    }
+    public void setInitValue(Initializer initValue) {
+        this.initValue = initValue;
+    }
+    public int toString(Object val, StringBuilder buf) {
+        int length0=buf.length();
+        if(val instanceof Obj) ((Obj)val).toString(buf);
+        else if(val!=null) buf.append(val.toString());
+        else buf.append("null");
+        return buf.length()-length0;
+    }
+    public Object get(Rec r,Object def){
+        return r.get(this, def);
+    }
+    public Slot set(Rec r,Object val){
+        r.set(this, val);
+        return this;
+    }
+}