From b6c1bf304627e6a32d8899e7fd14b046e507322e Mon Sep 17 00:00:00 2001
From: Alex Birkett <alex@birkett.co.uk>
Date: Mon, 1 Feb 2016 23:10:18 +0100
Subject: [PATCH] Remove symbol ids

Also absent from haxe port:
https://github.com/Tw1ddle/haxe-kiwi/commit/300617e5c0b041ca20842056c764d728b646f801
---
 src/main/java/no/birkett/kiwi/Solver.java | 16 +++++------
 src/main/java/no/birkett/kiwi/Symbol.java | 35 ++---------------------
 2 files changed, 9 insertions(+), 42 deletions(-)

diff --git a/src/main/java/no/birkett/kiwi/Solver.java b/src/main/java/no/birkett/kiwi/Solver.java
index 7cfc098..c256834 100644
--- a/src/main/java/no/birkett/kiwi/Solver.java
+++ b/src/main/java/no/birkett/kiwi/Solver.java
@@ -37,7 +37,6 @@ public class Solver {
     private List<Symbol> infeasibleRows = new ArrayList<Symbol>();
     private Row objective = new Row();
     private Row artificial;
-    private long idTick = 1;
 
 
     /**
@@ -327,11 +326,11 @@ public class Solver {
             case OP_LE:
             case OP_GE: {
                 double coeff = constraint.getOp() == RelationalOperator.OP_LE ? 1.0 : -1.0;
-                Symbol slack = new Symbol(Symbol.Type.SLACK, idTick++);
+                Symbol slack = new Symbol(Symbol.Type.SLACK);
                 tag.marker = slack;
                 row.insert(slack, coeff);
                 if (constraint.getStrength() < Strength.REQUIRED) {
-                    Symbol error = new Symbol(Symbol.Type.ERROR, idTick++);
+                    Symbol error = new Symbol(Symbol.Type.ERROR);
                     tag.other = error;
                     row.insert(error, -coeff);
                     this.objective.insert(error, constraint.getStrength());
@@ -340,8 +339,8 @@ public class Solver {
             }
             case OP_EQ: {
                 if (constraint.getStrength() < Strength.REQUIRED) {
-                    Symbol errplus = new Symbol(Symbol.Type.ERROR, idTick++);
-                    Symbol errminus = new Symbol(Symbol.Type.ERROR, idTick++);
+                    Symbol errplus = new Symbol(Symbol.Type.ERROR);
+                    Symbol errminus = new Symbol(Symbol.Type.ERROR);
                     tag.marker = errplus;
                     tag.other = errminus;
                     row.insert(errplus, -1.0); // v = eplus - eminus
@@ -349,7 +348,7 @@ public class Solver {
                     this.objective.insert(errplus, constraint.getStrength());
                     this.objective.insert(errminus, constraint.getStrength());
                 } else {
-                    Symbol dummy = new Symbol(Symbol.Type.DUMMY, idTick++);
+                    Symbol dummy = new Symbol(Symbol.Type.DUMMY);
                     tag.marker = dummy;
                     row.insert(dummy);
                 }
@@ -404,7 +403,7 @@ public class Solver {
 
         // Create and add the artificial variable to the tableau
 
-        Symbol art = new Symbol(Symbol.Type.SLACK, idTick++);
+        Symbol art = new Symbol(Symbol.Type.SLACK);
         rows.put(art, new Row(row));
 
         this.artificial = new Row(row);
@@ -638,8 +637,7 @@ public class Solver {
         if (vars.containsKey(variable)) {
             symbol = vars.get(variable);
         } else {
-            symbol = new Symbol(Symbol.Type.EXTERNAL, idTick++);
-            symbol.setVariableName(variable.getName());
+            symbol = new Symbol(Symbol.Type.EXTERNAL);
             vars.put(variable, symbol);
         }
         return symbol;
diff --git a/src/main/java/no/birkett/kiwi/Symbol.java b/src/main/java/no/birkett/kiwi/Symbol.java
index a851d8b..26e9892 100644
--- a/src/main/java/no/birkett/kiwi/Symbol.java
+++ b/src/main/java/no/birkett/kiwi/Symbol.java
@@ -14,48 +14,17 @@ public class Symbol {
     }
 
     private Type type;
-    private long id;
-    private String variableName;
 
     public Symbol() {
-        this(Type.INVALID, 0);
+        this(Type.INVALID);
     }
 
-    public Symbol(Type type, long id) {
+    public Symbol(Type type) {
         this.type = type;
-        this.id = id;
     }
 
     public Type getType() {
         return type;
     }
 
-    public void setType(Type type) {
-        this.type = type;
-    }
-
-    public long getId() {
-        return id;
-    }
-
-    public void setId(long id) {
-        this.id = id;
-    }
-
-    public String getVariableName() {
-        return variableName;
-    }
-
-    public void setVariableName(String variableName) {
-        this.variableName = variableName;
-    }
-
-    boolean lessThan(Symbol other) {
-        return this.id < other.getId();
-    }
-
-    boolean equals(Symbol other) {
-        return this.id == other.getId();
-    }
-
 }