Chapter 1: Elementary

Lesson 1: Contract Declaration

We begin with the basics. First of all, we will need to specify which Scilla version we are working with. At the moment of writing, Scilla is at version 0.2.0. We only need to be concerned with the first digit of the version, which is 0 here.

Now, we can start with the main part of the smart contract coding. The contract that you will be deploying to the blockchain has to have a name by which it could later be identified. We use contract and replace the ContractName with the actual name for the contract.

Please note that the contract name must start with a capital letter.

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scilla_version 0

We have a task for you!

Begin with the version declaration of Scilla as shown in the lesson.

Then, in next line, declare a contract which should be called SocialMediaPayment.

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Solution

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(* Start typing from the line below. *)
scilla_version 0
contract SocialMediaPayment

(* Start typing from the line below. *)

Chapter 1: Elementary

Lesson 2: Immutable variables

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Lesson 2: Immutable variables

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Cheat Sheet

Field Type	Field Type Keyword (Case Sensitive)	Mutable var declaration with Null value	Mutable var declaration with value	Declaration as a variable in transition	Declaration in the library
Signed Integer	`IntX` (Where X can be 32, 64, 128, or 256) `eg. Int32`	`field a: Option Int32 = None {Int32}`	`field a: Int32 = Int32 5`	`a = Int32 5`	`let a = Int32 5`
Unsigned Integer	`UintX` (Where X can be 32, 64, 128, or 256) `eg. Uint32`	`field a: Option Uint32 = None {Uint32}`	`field a: Uint32 = Uint32 5`	`a = Uint32 5`	`let a = Uint32 5`
String	`String`	`field a: String = ""`	`field a: String = "hello"`	`a = "hello"`	`let a = "xyz"`
Hash	`ByStr32`	`field a: Option ByStr32 = None {ByStr32}`	`field a: ByStr32 = 0x1234...0abff`	`a = 0x1234...0abff`	`let a = 0x1234...0abff`
Address	`ByStr20`	`field a: Option ByStr20 = None {ByStr20}`	`field a: ByStr20 = 0x1234...0abff`	`a = 0x1234...0abff`	`let a = 0x1234...0abff`
Block Number	`BNum`	`field a: Option BNum = None {BNum}`	`field a: BNum = BNum 5`	`a = BNum 5`	`let a = BNum 5`
Boolean	`Bool`	`field a: Option Bool = None {Bool}`	`field a: Bool = True`	`a = True`	`let a = True`
List	`List`	`field a: List(Int32) = Nil {Int32}`	`field a: List(Int32) = let b = Nil {Int32} in let c = Int32 5 in Cons {Int32} c b`	`a = Nil {Int32}`	`let a = Nil {Int32}`
Pair	`Pair (FieldType1) (Fieldtype2)`	`field a: Pair (String) (Option Uint32) = let b = "" in let c = None {Uint32} in Pair {(String) (Option Uint32)} b c`	`field a: Pair (String) (Uint32) = let b = "Hello" in let c = {Uint32} 5 in Pair {(String) (Uint32)} b c`	`a = let b = "Hello" in let c = {Uint32} 5 in Pair {(String) (Uint32)} b c`	`let a = let b= "Hello" in let c = {Uint32} 5 in Pair {(String) (Uint32)} b c`
Map	`Map FieldType1(Key) FieldType2(Value)` Keys can have the following types: `IntX` `UintX` `String` `ByStr32` `ByStr20` Values can be of any type.	`field a: Map FieldType1 FieldType2 = Emp FieldType1 FieldType2`	`field a: Map ByStr20 String = let b = Emp ByStr20 String in let c = 0x1234...0abff in let d = ""Hello"" in builtin put b c d "`	`a = let b = Emp ByStr20 String in let c = 0x1234...0abff in let d = ""Hello"" in builtin put b c d "`	`let a = let b = Emp ByStr20 String in let c = 0x1234...0abff in let d = ""Hello"" in builtin put b c d "`