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Before discussing Triggers in detail it is important to consider Events, which might play a big role in Trigger execution.
Events can originate from 2 places:
- Triggers can decide to emit events
- Events will be automatically emitted for WSV changes
- The events are based on WSV diff after particular transaction execution.
- Examples: AccountCreated(_), AcccountMetadataFieldSet(_), etc.
Events emitted during execution of entities in the current block are added to the block. Though Triggers can react to them only in the next block.
Representation
As you can see in the quote from the whitepaper the Triggers were initially planned to be represented as ISI.
But with the recent decision to introduce WASM, it is suggested to use it for Triggers. So that Triggers can be written in Rust* and compiled into WASM.
This way Triggers will benefit from a high level language features of an already established language and will be able to solve all the listed use cases with ease.
As discussed previously, solving listed use cases with ISI was impossible or very difficult and needed significant work on the language design side.
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