Language Reference

This section contains a reference to writing templates for Daml contracts. It includes:

• Overview: Template Structure
  • Template Outline Structure
  • Choice Structure
  • Choice Body Structure
• Reference: Templates
  • Template Name
  • Template Parameters
  • Implicit Record
  • this and self
  • Template-local Definitions (Deprecated)
    • Migration
    • Turning off the warning
  • Signatory Parties
  • Observers
  • Choices
  • Serializable Types
  • Agreements (Deprecated)
    • Migration
    • Turning off the warning
  • Preconditions
  • Contract Keys and Maintainers
  • Interface Instances
• Reference: Choices
  • Choice Name
  • Controllers
  • Choice Observers
    • Contract Consumption
  • Preconsuming Choices
  • Postconsuming Choices
  • Non-consuming Choices
    • Return Type
  • Choice Arguments
  • Choice Body
• Reference: Updates
  • Background
  • Binding Variables
  • do
  • archive
  • create
  • exercise
  • exerciseByKey
  • fetch
  • fetchByKey
  • visibleByKey
  • lookupByKey
  • abort
  • assert
  • getTime
  • return
  • let
  • this
• Reference: Data types
  • Built-in Types
    • Table of built-in primitive types
    • Escaping Characters
    • Time
  • Lists
    • Sum a List
  • Records and Record Types
    • Data Constructors
    • Access Record Fields
    • Update Record Fields
    • Parameterized Data Types
  • Type Synonyms
    • Function Types
  • Algebraic Data Types
    • Product Types
    • Sum Types
    • Pattern Matching
• Reference: Built-in functions
  • Work with Time
  • Work with Numbers
  • Work with Text
  • Work with Lists
    • Fold
• Reference: Expressions
  • Definitions
    • Values
    • Functions
  • Arithmetic Operators
  • Comparison Operators
  • Logical Operators
  • If-then-else
  • Let
• Reference: Functions
  • Defining Functions
  • Partial Application
  • Functions are Values
  • Generic Functions
• Reference: File structure
  • File Structure
  • Imports
  • Libraries
  • Comments
  • Contract Identifiers
• Reference: Packages
  • Building Daml Archives
  • Inspecting DARs
  • Import Daml Packages
    • Import a Daml package via Dependencies
    • Import a Daml Archive via data-dependencies
    • Transitive dependency management
    • Reference Daml Packages Already On the Ledger
  • Handling Module Name Collisions
• Reference: Contract keys
  • What Can Be a Contract Key
  • Specify Maintainers
  • Contract Lookups
    • fetchByKey
    • visibleByKey
    • lookupByKey
  • exerciseByKey
  • Example
• Reference: Exceptions
  • Builtin Errors
  • User-defined Exceptions
  • Throw Exceptions
  • Catch Exceptions
• Reference: Interfaces
  • Configuration
  • Interface Declaration
    • Interface Name
    • Implicit abstract type
    • Interface Methods
    • Interface View Type
    • Interface Choices
    • Empty Interfaces
  • Interface Instances
    • interface instance clause
    • interface instance clause in the interface
    • Empty interface instance clause
  • Interface Functions
    • interfaceTypeRep
    • toInterface
    • fromInterface
    • toInterfaceContractId
    • fromInterfaceContractId
    • coerceInterfaceContractId
    • fetchFromInterface
  • Required Interfaces
    • Interface Functions