Ledger contract

The Marmalade token standard provides interfaces that enable you to define, mint, and secure tokens. As discussed in Contract architecture, the Marmalade ledger contract provides the core functionality to create, manage, and transfer tokens minted using the Marmalade token standard. The ledger contract records and manages all token-related activity to ensure every transaction is accurate, every policy is enforced, and every account is up-to-date.

This part of the documentation describes the functions and capabilities defined in the Marmalade ledger contract.

Source code: ledger.pact

Use create-token-id to generate a unique token identifier with the specified token identifier.

Use the following arguments to create the token identifier.

Before creating a token, you must choose a temporary guard. The guard can be

This guard becomes part of the hashed data in the token-id string prefixed with t:. Including the guard in the hashed token identifier protects anyone else from creating the token. With this mechanism, only you—as the owner of the creation key—can create the token specified by the token-id string.

Generate a unique token-id by calling the following function:

(ledger.create-token-id details creation-guard)

Use create-token to create a token with the specified token identifier.

Use the following arguments to create a token.

To create a token with this function:

Use mint to mint the specified token amount to the specified account.

Use the following arguments to mint a token.

When you submit the mint transaction, the policy-manager.enforce-mint function calls the policy:enforce-mint function in the stored token policies and the function is executed at ledger.mint.

Use burn to destroy the specified token amount from the specified account.

Use the following arguments to burn a token.

When you submit the burn transaction, the policy-manager.enforce-burn function calls the policy:enforce-burn function in the stored token policies and the function is executed at ledger.burn.

Use transfer to transfer the specified token amount from the specified sender to the specified receiver.

Use the following arguments to transfer a token.

When you submit the transfer transaction, the policy-manager.enforce-transfer function calls the policy:enforce-transfer function in the stored token policies and the function is executed at ledger.transfer.

Use sale to execute a two-step transaction using the offer and buy steps with an escrow account as described in Token sales and trustless-escrow.

Because a sale requires two steps that must be completed in a specific order, the transaction is defined using a pact. For information about the syntax used to define a pact, see defpact.

Use the following arguments to initiate the sale of a token.

The first step of a sale pact (step 0) executes the offer function. The offer function transfers the token from the seller's account to the escrow account.

The policy-manager.enforce-offer function calls the policy:enforce-offer function in the stored token policies and the function is executed at step 0 of the sale.

The sale pact includes a rollback step (step 0-rollback). The rollback step executes the withdraw function. The withdraw function transfers the tokens held in the escrow account for the sale back to the seller. If a timeout is specified, the withdraw function can only be executed after the timeout period has passed. You can execute the withdraw function by sending a continuation (cont) command with the following information:

For more information about formatting continuation commands, see YAML Continuation command request

The policy-manager.enforce-withdraw function calls the policy:enforce-withdraw function in the stored token policies and the function is executed at step 0-rollback of sale.

The second step of a sale pact (step 1) executes the buy function. The buy function transfers the tokens held in the escrow account to the buyer. The buy function can be executed before timeout. The buyer and buyer-guard information is read from the env-data of the command instead of passing in arguments. Like the withdraw function, the buy function is executed using a continuation (cont) command:

The policy-manager.enforce-buy function calls the policy:enforce-buy function in the stored token policies and the function is executed at step 1 of sale.