# சாலிடிட்டி

**சாலிடிட்டி** (*solidity*) என்பது எண்ணிம குத்தைகையை உருவாக்கு உதவும் ஒரு நிரல் மொழியாகும்.  

## பண்புகள்
- சாலிடிட்டி, பிளாக்செயின் தொழில்நுட்பத்தில் இயங்கும் திறன் குத்தகைகளை உருவாக்கப் பயன்படுகின்றது.
- இந்நிரல் மொழி காவின் வுட், கிரிஸ்டியன் ரெயட்வியஸ்னர், அலெக்ஸ் பீரக்சாசி, லியான ஹஸ்கியன், யோச்சி ஹிராய் உள்ளிட்ட பல்வேறு ஈத்தரீயம் உருவாக்குனர்களால், திறன் குத்தகைகள் உருவாக்க கட்டமைக்கப்பட்டது.
- இம்மொழியைனை **.sol* என்ற பெயரில் சேமிக்க வேண்டும்.
- இந்நிரல் மொழியினை இணையத்திலோ, கணினியிலோ நிரல்மொழிமாற்றி உதவியுடன் சரிபார்க்க இயலும்.

## திறன் குத்தகை எடுத்துக்காட்டு
சாலிடிட்டி நிரலில் எழுதப்பட்ட ஒரு திறன் குத்தகை எடுத்துக்காட்டு<syntaxhighlight lang="js">  
pragma solidity ^0.4.4;  

contract Token {  

/// @return total amount of tokens  
function totalSupply constant returns (uint256 supply) {}  

/// @param _owner The address from which the balance will be retrieved  
/// @return The balance  
function balanceOf(address _owner) constant returns (uint256 balance) {}  

/// @notice send `_value` token to `_to` from `msg.sender`  
/// @param _to The address of the recipient  
/// @param _value The amount of token to be transferred  
/// @return Whether the transfer was successful or not  
function transfer(address _to, uint256 _value) returns (bool success) {}  

/// @notice send `_value` token to `_to` from `_from` on the condition it is approved by `_from`  
/// @param _from The address of the sender  
/// @param _to The address of the recipient  
/// @param _value The amount of token to be transferred  
/// @return Whether the transfer was successful or not  
function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {}  

/// @notice `msg.sender` approves `_addr` to spend `_value` tokens  
/// @param _spender The address of the account able to transfer the tokens  
/// @param _value The amount of wei to be approved for transfer  
/// @return Whether the approval was successful or not  
function approve(address _spender, uint256 _value) returns (bool success) {}  

/// @param _owner The address of the account owning tokens  
/// @param _spender The address of the account able to transfer the tokens  
/// @return Amount of remaining tokens allowed to spent  
function allowance(address _owner, address _spender) constant returns (uint256 remaining) {}  

event Transfer(address indexed _from, address indexed _to, uint256 _value);  
event Approval(address indexed _owner, address indexed _spender, uint256 _value);  

}  

contract StandardToken is Token {  

function transfer(address _to, uint256 _value) returns (bool success) {  
//Default assumes totalSupply can't be over max (2^256 - 1).  
//If your token leaves out totalSupply and can issue more tokens as time goes on, you need to check if it doesn't wrap.  
//Replace the if with this one instead.  
//if (balances[msg.sender] >= _value && balances[_to] + _value > balances[_to]) {  
if (balances[msg.sender] >= _value && _value > 0) {  
balances[msg.sender] -= _value;  
balances[_to] += _value;  
Transfer(msg.sender, _to, _value);  
return true;  
} else { return false; }  
}  

function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {  
//same as above. Replace this line with the following if you want to protect against wrapping uints.  
//if (balances[_from] >= _value && allowed[_from][msg.sender] >= _value && balances[_to] + _value > balances[_to]) {  
if (balances[_from] >= _value && allowed[_from][msg.sender] >= _value && _value > 0) {  
balances[_to] += _value;  
balances[_from] -= _value;  
allowed[_from][msg.sender] -= _value;  
Transfer(_from, _to, _value);  
return true;  
} else { return false; }  
}  

function balanceOf(address _owner) constant returns (uint256 balance) {  
return balances[_owner];  
}  

function approve(address _spender, uint256 _value) returns (bool success) {  
allowed[msg.sender][_spender] = _value;  
Approval(msg.sender, _spender, _value);  
return true;  
}  

function allowance(address _owner, address _spender) constant returns (uint256 remaining) {  
return allowed[_owner][_spender];  
}  

mapping (address => uint256) balances;  
mapping (address => mapping (address => uint256)) allowed;  
uint256 public totalSupply;  
}  

//name this contract whatever you'd like  
contract LaxmiCoin is StandardToken {  

function {  
//if ether is sent to this address, send it back.  
throw;  
}  

/* Public variables of the token */  

/*  
NOTE:  
The following variables are OPTIONAL vanities. One does not have to include them.  
They allow one to customise the token contract & in no way influences the core functionality.  
Some wallets/interfaces might not even bother to look at this information.  
- /
string public name; //fancy name: eg Simon Bucks  
uint8 public decimals; //How many decimals to show. ie. There could 1000 base units with 3 decimals. Meaning 0.980 SBX = 980 base units. It's like comparing 1 wei to 1 ether.  
string public symbol; //An identifier: eg SBX  
string public version = 'H1.0'; //human 0.1 standard. Just an arbitrary versioning scheme.  

//  
// CHANGE THESE VALUES FOR YOUR TOKEN  
//  

//make sure this function name matches the contract name above. So if you're token is called TutorialToken, make sure the //contract name above is also TutorialToken instead of ERC20Token  

function LaxmiCoin {  
balances[msg.sender] = 21000000; // Give the creator all initial tokens (100000 for example)  
totalSupply = 21000000; // Update total supply (100000 for example)  
name = "Laxmi Coin"; // Set the name for display purposes  
decimals = 0; // Amount of decimals for display purposes  
symbol = "LAXMI"; // Set the symbol for display purposes  
}  

/* Approves and then calls the receiving contract */  
function approveAndCall(address _spender, uint256 _value, bytes _extraData) returns (bool success) {  
allowed[msg.sender][_spender] = _value;  
Approval(msg.sender, _spender, _value);  

//call the receiveApproval function on the contract you want to be notified. This crafts the function signature manually so one doesn't have to include a contract in here just for this.  
//receiveApproval(address _from, uint256 _value, address _tokenContract, bytes _extraData)  
//it is assumed that when does this that the call *should* succeed, otherwise one would use vanilla approve instead.  
if(!_spender.call(bytes4(bytes32(sha3("receiveApproval(address,uint256,address,bytes)"))), msg.sender, _value, this, _extraData)) { throw; }  
return true;  
}  
}  
</syntaxhighlight>