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Find details on the SPL language, toolkits, APIs, commands, and more.
Streams Processing Language (SPL)
Streams Processing Language (SPL) is a distributed data flow composition language that is used in Teracloud® Streams. SPL has primitive types, program structures, and definitions that are tailored for streaming data.
Types
SPL has several primitive types that are tailored for streaming, and a few composite types that are inspired by scripting languages but statically checked. The following topics describe the types, how to define them, and how to convert values between different types.
Composite types
A composite type is the result of applying a type constructor to one or more type arguments.

Welcome
Learn about the core capabilities of Teracloud® Streams, its architecture, and key concepts.
Installing
Use this information to install, upgrade, and uninstall the Teracloud® Streams product.
Configuring
Create a basic or an enterprise domain which is a single point for configuring and managing common resources, security, and instances.
Administering
Administer the product by using the Teracloud® Streams graphical user interface, APIs, or the streamtool command-line interface.
Developing
Develop stream applications with the Streams Processing Language (SPL), Java, and Python.
Troubleshooting
Resolve problems with Teracloud® Streams using the troubleshooting tools provided with the product as well as the resources offered by Teracloud Support.
Reference
Find details on the SPL language, toolkits, APIs, commands, and more.
- APIs
  Application programming interfaces (APIs) provide functions that simplify applications development.
- Job configuration overlays
  You can specify or change configuration parameters when you use the submitjob or updateoperators operations. The settings control submission constraints, host constraints and locations, and operator status. Parameters are captured and updated in the configuration JSON file. When you change the values in the job configuration overlay file, the changes override any previously set values.
- Commands
  Teracloud® Streams provides a number of commands you use to perform tasks.
- Operator model
  An operator model is an XML document that describes the basic properties of a primitive operator.
- Streams Processing Language (SPL)
  Streams Processing Language (SPL) is a distributed data flow composition language that is used in Teracloud® Streams. SPL has primitive types, program structures, and definitions that are tailored for streaming data.
  - Language overview
    SPL contains types, expressions, statements, functions, clauses, and other elements of a programming language.
  - Grammar notation
    This language specification adopts a flavor of Backus-Naur Form (BNF) to describe the syntax of language features.
  - Lexical syntax
    SPL defines a set of rules to determine the syntax of a program.
  - Grammar overview
    Here is the SPL grammar syntax, with references to the sections that contain the semantics.
  - Expression language
    Though SPL is a streaming language, there are many places where it uses expressions that are found in traditional imperative or functional languages.
  - Annotations
    Operators can be annotated. Annotations influence the run time behavior of stream applications.
  - Types
    SPL has several primitive types that are tailored for streaming, and a few composite types that are inspired by scripting languages but statically checked. The following topics describe the types, how to define them, and how to convert values between different types.
    - Primitive types
      A primitive type, such as int32 or rstring, is one that is not composed of other types.
    - Composite types
      A composite type is the result of applying a type constructor to one or more type arguments.
      - Collections
        SPL has three built-in collections (list, set, and map).
      - Tuples
        A tuple is a sequence of attributes, and an attribute is a named value.
      - Optional types
        In SPL, an optional type is used when a variable or attribute might have no data value associated with it because the value is unavailable or unknown. When there is no data value for a variable or attribute, and an optional type is used, the value of that variable or attribute can be set to null.
    - Type definitions
      A type definition gives a name to a type,
    - Value semantics
      All primitive and composite SPL types have value semantics, not reference semantics.
    - Type conversions
      SPL is statically typed and strongly typed and has structural equivalence.
  - Operators
    Operators process tuples in an incoming stream and produce an output stream as a result. SPL supports two kinds of operators: primitive operators and composite operators. A primitive operator is written in C++ or Java™. A composite operator is written in SPL and contains a reusable stream subgraph.
  - Program structure
  - Operator config clause
    The config clause specifies hints and directives that influence how the compiler builds an operator invocation, or how the runtime system runs it.
- Toolkits
  A toolkit is a set of SPL artifacts, which are organized into a package. Toolkits make SPL or native functions and primitive or composite operators reusable across different applications.
- SPLDOC markup
  You can use SPLDOC markup in the descriptions associated with the SPL artifacts in a toolkit. The spl-make-doc command generates HTML documentation from the marked up artifacts.
Glossary
Use this glossary to find terms and definitions for Teracloud® Streams.

Composite types

A composite type is the result of applying a type constructor to one or more type arguments.

For example, the composite type list<int32> is the result of applying the type constructor list<T> to the type argument T=int32.