Liquidity is a high-level typed smart-contract language for Tezos that strictly complies to Michelson security restrictions. A formal verification framework for it is under development.

Try Online Learn More Documentation Github Repo

About Liquidity


Liquidity is a high-level language to program Smart Contracts for Tezos. It is a fully typed functional language, it uses the syntax of OCaml, and strictly complies to Michelson security restrictions.

A formal-method framework for Liquidity is under development, to prove the correctness of smart-contracts written in Liquidity.

The Liquidity language provides the following features:

  • full coverage of the Michelson language: Anything that can be written in Michelson can be written in Liquidity,
  • local variables instead of stack manipulations: values can be stored in local variables. The only restriction is that local variables do not survive to Contract.call, following the philosophy of Michelson to force explicite storage of values to limit reentrancy bugs,
  • high-level types: types like sum-types and record-types can be defined and used in Liquidity programs.

Liquidity already covers 100% of the Michelson features, and contracts generated with Liquidity can be submitted on the current alphanet.

Liquidity Online


Liquidity editors will soon be available to program online and submit contracts on Tezos testnet. For now, you can use our Try Liquidity Site to get a taste of the upcoming environment.

Documentation & Examples


Liquidity Documentation is available in the Github project documentation. Examples are also available in the Github project, or in the online editor.

A typical example is:

 [%%version 0.13]

 type storage = (string, int) map
 
 let%entry main
   (parameter : string)
   (storage : storage)
   : unit * storage =

   let amount = Current.amount() in

   if amount < 5.00tz then
     Current.fail ()
   else
     match Map.find parameter storage with
     | None ->
       Current.fail ()
     | Some x ->
       let storage = Map.add parameter (x+1) storage in
       ( (), storage ) 

Liquidity Team


Alain Mebsout
Çağdaş Bozman
Fabrice Le Fessant
Michael Laporte
Mohamed Iguernlala

Liquidity Roadmap


The current roadmap is:

  • Development of an online editor for Liquidity
  • Development of a verification framework for Liquidity contracts

Changelog


0.13  2017-11-30
    NEW FEATURES
    * match%nat construct for int -> nat coercion
    * abs is now int -> int
    * Command line options --parse-only, --type-only
    * Command line options --single-line, --compact to output
      Michelson on a single line
    * Support &&, || Boolean connectors
    * Support Map.add, Map.remove, Set.add, Set.remove
    * Lambda types are now written as t1 -> t2 instead of
      (t1, t2) lambda
    * Constant amounts written as litterals: 1.00tz
    * Constant keys and key_hashes as litterals: edpk... tz1...
    * Timestamps as litterals in ISO-8601 format

    IMPROVEMENTS
    * Split typechecking and encoding phases
    * Allow transfers in conditions (for if-then-else and match)
    * Encode to constants when possible
    * Better error messages
    * Accept any name for result of Contract.call
    * Recover variable names when decompiling

    BUG FIXES
    * Fix bug in encoding of closures
    * Fix bug in compilation of branches with transfers

0.11  2017-10-16
    NEW FEATURES
    * Compilation of Liquidity contracts to OCaml bytecode
    * Deconstruct tuples in let, fun and pattern matching
    * Support _ for pattern
    * OCaml syntax for return type of contract's entry point
    * Support for type key_hash

    IMPROVEMENTS
    * Allow compilation without Tezos
    * Better error messages
    * Error location in Michelson source when decompiling
    * Declare type storage when decompiling
    * More efficient encoding of closures

0.1   2017-10-05
    Initial release 
This website uses the creative template of startbootstrap.com
The background image is licensed under CC0
© 2017 OCamlPro SAS, All rights reserved.
Get it touch with us
Legal