$//$CAB$301-$ Assignment $2$

$//$Tool ADT specification

using System;

using System.Text;

$//$Invariants: Name$=!$null and Number $>=1$

public interface ITool

$\{$

$//$ get the name of this tool

string Name $//$ get the name of this tool

$\{$

get;

$\}$

$//$get the number of this tool currently available in the tool library

int Number

$\{$

get;

$\}$

$//$check if a person is in the borrower list of this tool $($is holding this tool$)$

$//$Pre$-$condition: nil

$//$Post$-$condition: return true if the person is in the borrower list; return false otherwise. The information about this tool remains unchanged.

bool IsInBorrowerList$($string personName$)$;

$//$add a person to the borrower list

$//$Pre$-$condition: the borrower is not in the borrower list and Number $>0$

$//$Post$-$condition: the borrower is added to the borrower list and New Number $=$ Old Number $-1$

bool AddBorrower$($string personName$)$;

$//$remove a borrower from the borrower list

$//$Pre$-$condition: the borrower is in the borrower list

$//$Post$-$condition: the borrower is removed from the borrower list and and new Number $=$ old Number $+1$

bool RemoveBorrower$($string personName$)$;

$//$Compare this tool's name to another tool's name

$//$Pre$-$condition: anotherTool $=!$ null

$//$Post$-$condition: return $-1,$ if this tool's name is less than another tool's name by alphabetical order

$//$ return $0,$ if this tool's name equals to another tool's name by alphabetical order

$//$ return $+1,$ if this tool's name is greater than another tool's name by alphabetical order

int CompareTo$($ITool$?$ anotherTool$)$;

$//$Return a string containing the name and the number of this tool currently in the tool library

$//$Pre$-$condition: nil

$//$Post$-$condition: A string containing the name and number of this tool is returned

string ToString$()$;

$\}$