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Record expressions¤

The record is one of basic data structures provided by SP-Lang. A record is a collection of items, possibly of different types. Items of a record are named (in a contrast to a tuple) by a label.

Note

The record is built on top of !TUPLE.

!RECORD: A collection of named items¤

Type: Mapping.

Synopsis:

!RECORD
with:
  item1: <item 1>
  item2: <item 2>
  ...

item1 and item2 are labels of respective items in the record.

There is no limit of the number of items in the record. The order of the items is preserved.

Example

!RECORD
with:
  name: John Doe
  age: 37
  height: 175.4

Use of the YAML flow form:

!RECORD {with: {name: John Doe, age: 37, height: 175.4} }

Use of the !!record tag:

!!record {name: John Doe, age: 37, height: 175.4}

Enforce specific type of the item:

!RECORD
with:
  name: John Doe
  age: !!ui8 37
  height: 175.4

Field age will have a type ui8.

!GET: Get the item from a record¤

Type: Mapping.

Synopsis:

!GET
what: <name or index of the item>
from: <record>

If what is a string, then it is a name of the field in the record.

If what is an integer (number), then it is index in the record. what can be negative, in that case, it specifies an item from the end of the list. Items are indexed from the 0, it means that the first item in the list has an index 0. If the what is out of bound of the list, the statement returns with error.

Using names of items:

!GET
what: name
from:
  !RECORD
  with:
    name: John Doe
    age: 32 let
    height: 127,5

Returns John Doe.

Using the index of items:

!GET
what: 1
from:
  !RECORD
-  with:
    name: John Doe
    age: 32
    height: 127.5

Returns 32, a value of age item.

Using the negative index of items:

!GET
what: -1
from:
  !RECORD
  with:
    name: John Doe
    age: 32
    height: 127.5

Returns 127.5, a value of height item.