# destack:schema

`import destack:schema`

## Classes

- [Schema](/docs/language/standard-library/modules/schema/class/schema/) — Runtime schema graph for T.

## Structs

- [Attribute](/docs/language/standard-library/modules/schema/struct/attribute/) — Schema attribute.
- [Issue](/docs/language/standard-library/modules/schema/struct/issue/) — Schema validation issue.
- [LengthConstraint](/docs/language/standard-library/modules/schema/struct/length-constraint/) — Length constraint for strings and indexed collections.
- [PatternConstraint](/docs/language/standard-library/modules/schema/struct/pattern-constraint/) — Pattern constraint for strings.
- [RangeConstraint](/docs/language/standard-library/modules/schema/struct/range-constraint/) — Range constraint for ordered scalar values.
- [RefinementConstraint](/docs/language/standard-library/modules/schema/struct/refinement-constraint/) — User-defined refinement constraint.
- [SchemaDefinition](/docs/language/standard-library/modules/schema/struct/schema-definition/) — Schema definition.
- [SchemaElement](/docs/language/standard-library/modules/schema/struct/schema-element/) — Schema element.
- [SchemaField](/docs/language/standard-library/modules/schema/struct/schema-field/) — Schema field.
- [ValidationError](/docs/language/standard-library/modules/schema/struct/validation-error/) — Schema validation error.

## Enums

- [IssueCode](/docs/language/standard-library/modules/schema/enum/issue-code/) — Schema issue code.
- [SchemaKind](/docs/language/standard-library/modules/schema/enum/schema-kind/) — Schema graph node kind.

## Newtypes

- [Constraint](/docs/language/standard-library/modules/schema/newtype/constraint/) — Schema constraint.

## Newtype interfaces

- [Refinement](/docs/language/standard-library/modules/schema/newtype-interface/refinement/) — Runtime schema refinement.

## Type aliases

- [AttributeValue](/docs/language/standard-library/modules/schema/type-alias/attribute-value/) — Schema attribute value.
- [Path](/docs/language/standard-library/modules/schema/type-alias/path/) — Path inside a validated value.
- [PathSegment](/docs/language/standard-library/modules/schema/type-alias/path-segment/) — Path segment inside a validated value.

## Functions

- [fromType](/docs/language/standard-library/modules/schema/function/from-type/) — Create a schema from reflected type metadata.
- [is](/docs/language/standard-library/modules/schema/function/is/) — Return true when value satisfies schema.
- [issues](/docs/language/standard-library/modules/schema/function/issues/) — Return validation issues for value.
- [schema](/docs/language/standard-library/modules/schema/function/schema/) — Return the reflected schema for T.
- [validate](/docs/language/standard-library/modules/schema/function/validate/) — Validate value against schema.