Types — Marreta Lang

Marreta uses one set of types everywhere. The same types describe schema contracts, request payloads, responses, and the values your code works with at runtime. A field declared amount: decimal is validated on the way in, shaped on the way out, and is a real decimal in between.

Scalar types

Type	Meaning	Page
`string`	Text.	string
`integer`	A whole number.	integer
`float`	A floating-point number.	float
`decimal`	An exact decimal, safe for money.	decimal
`boolean`	`true` or `false`.	boolean

Collection types

Type	Meaning	Page
`list`	An ordered list of values.	list
`map`	A key-value object.	map

Temporal types

Type	Meaning
`instant`	A point in time.
`date`	A calendar date.
`time`	A wall-clock time.
`duration`	A length of time.
`interval`	A span between two instants.

These are constructed and read through the time namespace. See Temporal types for construction, properties, and the on method.

Schema constructs

These appear in schema definitions to compose other types:

Form	Meaning
`enum ["a", "b"]`	One of a fixed set of strings.
`<Schema>`	A reference to another schema, a foreign-key relation when the target is persistent.
`list of <Schema>`	A typed list of another schema.