| 1 | package tuffy.mln; |
| 2 | |
| 3 | import tuffy.util.ExceptionMan; |
| 4 | |
| 5 | /** |
| 6 | * A term in first-order logic; either a variable or a constant. |
| 7 | */ |
| 8 | public class Term { |
| 9 | |
| 10 | /** |
| 11 | * Whether this term is a variable. |
| 12 | */ |
| 13 | private boolean isVariable; |
| 14 | |
| 15 | public boolean isOriAConstant = false; |
| 16 | |
| 17 | public int oriConstantID = -1; |
| 18 | |
| 19 | /** |
| 20 | * The name of this term. $var$ is not null iff. |
| 21 | * this term is a variable. |
| 22 | */ |
| 23 | private String var = null; |
| 24 | |
| 25 | /** |
| 26 | * The ID of this term. $constantID$ is not null iff. |
| 27 | * this term is a constant. |
| 28 | */ |
| 29 | private Integer constantID = null; |
| 30 | |
| 31 | |
| 32 | /** |
| 33 | * Constructor of Term (variable version). |
| 34 | * |
| 35 | * @param var name of the variable |
| 36 | */ |
| 37 | public Term(String var){ |
| 38 | isVariable = true; |
| 39 | this.var = var; |
| 40 | } |
| 41 | |
| 42 | public void reSet(String var){ |
| 43 | if(isVariable == false){ |
| 44 | ExceptionMan.die("Cannot reset a constant term with a variable!"); |
| 45 | } |
| 46 | this.var = var; |
| 47 | } |
| 48 | |
| 49 | public void reSet(Integer cid){ |
| 50 | if(isVariable == true){ |
| 51 | ExceptionMan.die("Cannot reset a variable term with a constant!"); |
| 52 | } |
| 53 | this.constantID = cid; |
| 54 | } |
| 55 | |
| 56 | /** |
| 57 | * Constructor a Term (constant version). |
| 58 | * |
| 59 | * @param cid the constant in the form of its integer ID |
| 60 | */ |
| 61 | public Term(Integer cid){ |
| 62 | isVariable = false; |
| 63 | constantID = cid; |
| 64 | } |
| 65 | |
| 66 | /** |
| 67 | * Return whether this term is a variable. |
| 68 | */ |
| 69 | public boolean isVariable(){ |
| 70 | return isVariable; |
| 71 | } |
| 72 | |
| 73 | /** |
| 74 | * |
| 75 | * @return Whether this term is a constant. |
| 76 | */ |
| 77 | public boolean isConstant(){ |
| 78 | return !isVariable; |
| 79 | } |
| 80 | |
| 81 | /** |
| 82 | * @return The name of this term, which is null when it is |
| 83 | * a constant. |
| 84 | */ |
| 85 | public String var(){ |
| 86 | return var; |
| 87 | } |
| 88 | |
| 89 | /** |
| 90 | * |
| 91 | * @return The name of this term, which is null when it is |
| 92 | * a variable. |
| 93 | */ |
| 94 | public int constant(){ |
| 95 | return constantID; |
| 96 | } |
| 97 | |
| 98 | /** |
| 99 | * @return This term's human-friendly representation. |
| 100 | */ |
| 101 | public String toString() { |
| 102 | if(isVariable) { |
| 103 | return var; |
| 104 | }else { |
| 105 | return Integer.toString(constantID); |
| 106 | } |
| 107 | } |
| 108 | |
| 109 | } |