Syntax

Grammar

• annotate-expression → ( expression :: type )
  

  Annotate an expression with a type.

• apply-expression → ( expression . expression )
  

  Function application using the . operator.

• as-expression → ( expression as type )
  

  Convert a value of one type to a value of a different type.

• assignment → ( pattern : expression )
  

  Assign a value to a pattern.

• attribute → (attribute | ( ( name ) : attribute-value ))
  

  An attribute.

• attribute-value → (name | number | text)
  

  An attribute value.

• binary-operator-expression → (( expression to expression ) | ( expression by expression ) | ( expression ^ expression ) | ( expression * expression ) | ( expression / expression ) | ( expression % expression ) | ( expression + expression ) | ( expression - expression ) | ( expression < expression ) | ( expression <= expression ) | ( expression > expression ) | ( expression >= expression ) | ( expression = expression ) | ( expression /= expression ) | ( expression and expression ) | ( expression or expression ))
  

  An expression involving a binary operator.

• block-expression → { statement ... }
  

  A block expression.

• block-type → ({ type ... })
  

  A type whose value is computed from a block expression.

• call-expression → ( expression ... )
  

  Call a function with at least one input.

• collection-expression → ( expression , ... )
  

  A collection.

• constant-declaration → ( ( name ) :: (( type-function => type ) | type) )
  

  A constant declaration.

• declared-type → (name | ( name type ... ))
  

  A declared type, optionally with parameters.

• destructure-pattern → { ( ( name ) : pattern ) ... }
  

  A pattern that matches the fields of a structure.

• do-expression → ( do expression )
  

  Call an intrinsic function provided by the runtime.

• equal-type → ( type = type )
  

  Use two types in the place of one.

• expression → (annotate-expression | name-expression | number-expression | text-expression | apply-expression | binary-operator-expression | as-expression | is-expression | when-expression | intrinsic-expression | tuple-expression | collection-expression | structure-expression | block-expression | function-expression | do-expression | call-expression)
  

  An expression.

• function-expression → ( (( pattern ... ) | function-inputs) -> expression )
  

  A function expression.

• function-type → ( (( type ... ) | function-inputs) -> type )
  

  A function type.

• instance → ( name type ... )
  

  An instance.

• instance-declaration → (( (( type-function => ( default instance instance ) ) | ( default instance instance )) : expression ) | (( type-function => ( default instance instance ) ) | ( default instance instance )))
  

  A default instance declaration.

• instance-declaration → (( (( type-function => ( instance instance ) ) | ( instance instance )) : expression ) | (( type-function => ( instance instance ) ) | ( instance instance )))
  

  An instance declaration.

• intrinsic-expression → ( intrinsic text expression ... )
  

  Call an intrinsic function provided by the runtime.

• intrinsic-type → intrinsic
  

  An intrinsic type provided by the runtime.

• is-expression → ( expression is pattern )
  

  Check if a value matches a pattern.

• message-type → (text | ( text type ... ))
  

  A type-level piece of text used to generate compiler errors.

• mutate-pattern → ( name ! )
  

  A pattern that changes the value of an existing variable.

• name-expression → name
  

  A name.

• number-expression → number
  

  A number.

• number-pattern → number
  

  A pattern that matches a number.

• or-pattern → ( pattern or pattern )
  

  A pattern that matches either one of its subpatterns.

• pattern → (wildcard-pattern | number-pattern | text-pattern | destructure-pattern | tuple-pattern | or-pattern | mutate-pattern | variant-pattern | annotate-pattern)
  

  A pattern.

• placeholder-type → _
  

  An inferred type.

• statement → (syntax-declaration | type-declaration | trait-declaration | instance-declaration | instance-declaration | constant-declaration | assignment | statement)
  

  A statement.

• structure-expression → { ( ( name ) : expression ) ... }
  

  A structure.

• syntax-declaration → ( intrinsic text )
  

  A syntax declaration.

• text-expression → text
  

  A piece of text.

• text-pattern → text
  

  A pattern that matches a piece of text.

• top-level → ({} | { statement ... })
  

  A file or code box.

• trait-declaration → ( ( name ) : (( trait ) | ( trait type ) | ( type-function => (( trait ) | ( trait type )) )) )
  

  A trait declaration.

• tuple-expression → ( expression ; ... )
  

  A tuple.

• tuple-pattern → ( pattern ; ... )
  

  A pattern that matches a tuple.

• tuple-type → ( type ; ... )
  

  A tuple type.

• type → (placeholder-type | function-type | tuple-type | block-type | intrinsic-type | message-type | equal-type | declared-type)
  

  A type.

• type-declaration → ( ( name ) : (( type ) | ( type type-representation ) | ( type-function => ( type ) ) | ( type-function => ( type type-representation ) )) )
  

  A type declaration.

• type-function → (( type-parameter ... ) | ( (( _ ) | ( type-parameter ... )) where ( instance ... ) ))
  

  Provides generic type parameters and bounds to a declaration.

• type-parameter → (name | ( infer name ) | ( (( name ) | ( infer name )) : type ))
  

  A type parameter.

• type-representation → ({ (( ( name ) :: type ) | ( name type ... )) ... } | type)
  

  A set of fields or variants in a type.

• variant-pattern → (name | ( name pattern ... ))
  

  A pattern that matches a variant or binds to a variable.

• when-arm → ( pattern -> expression )
  

  An arm in a when expression.

• when-expression → ( when expression { when-arm ... } )
  

  Match a value against a set of patterns.

• wildcard-pattern → _
  

  A pattern that matches any value.