Declarations¶

Branchline programs are composed of top-level declarations that introduce sources, outputs, transformations, and reusable definitions.

Source declarations¶

sourceDecl ::= SOURCE IDENTIFIER adapterSpec? ;

Each SOURCE names an input and optionally specifies an adapter that reads data【F:language/src/test/kotlin/v2/ebnf.txt†L22-L31】.

Output declarations¶

outputDecl ::= OUTPUT adapterSpec? templateBlock

An OUTPUT sends data through an optional adapter and a template block that describes the resulting structure【F:language/src/test/kotlin/v2/ebnf.txt†L26-L31】.

Transform declarations¶

transformDecl ::= annotation* TRANSFORM IDENTIFIER? transformMode? block

Transforms process data from sources to outputs, optionally annotated or modeled as a stream or buffer【F:language/src/test/kotlin/v2/ebnf.txt†L45-L49】.

Shared declarations¶

sharedDecl ::= SHARED IDENTIFIER ( SINGLE | MANY )? ;

Shared memory exposes mutable storage that can be SINGLE or MANY valued【F:language/src/test/kotlin/v2/ebnf.txt†L55-L55】.

Function declarations¶

funcDecl ::= FUNC IDENTIFIER "(" paramList? ")" funcBody

Functions define reusable computations, taking an optional parameter list and either an expression or block body【F:language/src/test/kotlin/v2/ebnf.txt†L61-L63】.

Type declarations¶

typeDecl ::= TYPE IDENTIFIER "=" typeExpr ;
typeExpr ::= enum "{" enumVal ("," enumVal)* "}" | simpleType ( "|" simpleType )*

Type definitions describe new enums or compositions of built-in types such as string, number, boolean, null, and generic arrays【F:language/src/test/kotlin/v2/ebnf.txt†L65-L70】.