Canonicalizer

A pure and deterministic function that simplifies a JSON Schema definition to ease the static analysis process. More...

Modules
	Syntax Sugar
	Syntax sugar canonicalization rules aim to simplify the keywords of JSON Schema that JSON BinPack has to deal with. A canonicalization rule is considered to be part of this category if the semantics of the schema can be expressed using simpler keywords.
	Superfluous Keywords
	Superfluous keywords canonicalization rules aim to remove keywords that are not providing any value to the given schema. A canonicalization rule is considered to be part of this category if the semantics of the schema remain the same after removing a certain keyword.
	Heterogeneous Schemas
	Heterogeneous schemas canonicalization rules aim to simplify schemas by ensuring that any subschema only applies to one and only one JSON data type. A canonicalization rule is considered to be part of this category if it is about turning heterogeneous schemas into homogeneous schemas.
	Implicit Constraints
	Implicit constraints canonicalization rules aim to surface constraints that might apply without the schema reader realizing that this is the case. A canonicalization rule is considered to be part of this category if it is about making implicit constraints explicit.
	Schema Simplification
	Schema simplification canonicalization rules aim to reduce the complexity of schemas by representing the current constraints in a different, simpler manner. A canonicalization rule is considered to be part of this category if it is about applying complex transformations for simplification purposes.

Classes
class	sourcemeta::jsonbinpack::Canonicalizer

Detailed Description

A pure and deterministic function that simplifies a JSON Schema definition to ease the static analysis process.

JSON Schema is a particularly expressive and complex schema language. To mitigate such complexity in the context of static analysis, the Canonicalizer component is a total function that maps JSON Schema definitions to equivalent but simpler JSON Schema definitions according to a set formal transformations. The concept of simplifying JSON Schema definitions based on formal transformations for static analysis purposes was originally introduced by Type Safety with JSON Subschema. We extend their work by modernizing and extending their set of canonicalization rules.

The canonicalizer repeatedly applies the set of defined canonizalization transformations rules to every subschema of a given JSON Schema definition until no more transformations are possible. A JSON Schema definition that cannot be further modified by any canonizalization rule is considered to be a Canonical JSON Schema. In order to prevent an infinite loop in the canonizalization algorithm, canonizalization rules do not conflict with each other and the pre-condition of a given canonizalization rule does not hold after such canonizalization rule has been applied to the schema.

Inspired by the notation introduced by Type Safety with JSON Subschema, each canonizalization rule is defined using the form where corresponds to the JSON Schema in question.

See also

Mapper