Contract currency
Contract Code
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balances = Hash(default_value=0, contract='currency', name='balances')
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def (vk: str):
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balances[vk] = 288090567
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@export('currency')
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def transfer(amount: float, to: str):
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assert amount > 0, 'Cannot send negative balances!'
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sender = ctx.caller
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assert balances[sender] >= amount, 'Not enough coins to send!'
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balances[sender] -= amount
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balances[to] += amount
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@export('currency')
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def balance_of(account: str):
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return balances[account]
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@export('currency')
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def allowance(owner: str, spender: str):
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return balances[owner, spender]
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@export('currency')
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def approve(amount: float, to: str):
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assert amount > 0, 'Cannot send negative balances!'
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sender = ctx.caller
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balances[sender, to] += amount
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return balances[sender, to]
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@export('currency')
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def transfer_from(amount: float, to: str, main_account: str):
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assert amount > 0, 'Cannot send negative balances!'
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sender = ctx.caller
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assert balances[main_account, sender
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] >= amount, 'Not enough coins approved to send! You have {} and are trying to spend {}'.format(
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balances[main_account, sender], amount)
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assert balances[main_account] >= amount, 'Not enough coins to send!'
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balances[main_account, sender] -= amount
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balances[main_account] -= amount
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balances[to] += amount
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