Lists and Comprehensions

Lists

A list is a collection of values of the same type. A list literal is written as [...]

The type of a list is List(type).

Comprehensions

A list comprehension is of the form

[ expression | clause, clause, ... ]

where each clause is

• a generator var <- expression or (var, ..., var) <- expression

• a filter expression

• or an assignment var := expression

Each var can also be a list of variables surrounded by parenthesis to destructure a tuple.

Examples

[]                                      # The empty list
["foo"]                                 # A singleton list containing string "foo"
[1*|metre|, 2*|metre|, 3*|metre|]       # A list with three numbers of unit metre
[[1,2], [3,4]]                          # A list of lists of dimensionless numbers

The types of above examples are

for_type t: List(t)
List(String)
List(metre)
List(List(1))