cuelang.org/go@v0.13.0/encoding/jsonschema/version.go (about)

     1  // Copyright 2024 CUE Authors
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package jsonschema
    16  
    17  import (
    18  	"fmt"
    19  	"strings"
    20  )
    21  
    22  //go:generate go run golang.org/x/tools/cmd/stringer -type=Version -linecomment
    23  
    24  type Version int
    25  
    26  const (
    27  	VersionUnknown Version = iota // unknown
    28  	VersionDraft4                 // http://json-schema.org/draft-04/schema#
    29  	// Note: draft 5 never existed and should not be used.
    30  	VersionDraft6       // http://json-schema.org/draft-06/schema#
    31  	VersionDraft7       // http://json-schema.org/draft-07/schema#
    32  	VersionDraft2019_09 // https://json-schema.org/draft/2019-09/schema
    33  	VersionDraft2020_12 // https://json-schema.org/draft/2020-12/schema
    34  
    35  	numJSONSchemaVersions // unknown
    36  
    37  	// Note: The following versions stand alone: they're not in the regular JSON Schema lineage.
    38  	VersionOpenAPI       // OpenAPI 3.0
    39  	VersionKubernetesAPI // Kubernetes API
    40  	VersionKubernetesCRD // Kubernetes CRD
    41  )
    42  
    43  const (
    44  	openAPI     = versionSet(1 << VersionOpenAPI)
    45  	k8sAPI      = versionSet(1 << VersionKubernetesAPI)
    46  	k8sCRD      = versionSet(1 << VersionKubernetesCRD)
    47  	k8s         = k8sAPI | k8sCRD
    48  	openAPILike = openAPI | k8s
    49  )
    50  
    51  // is reports whether v is in the set vs.
    52  func (v Version) is(vs versionSet) bool {
    53  	return vs.contains(v)
    54  }
    55  
    56  type versionSet int
    57  
    58  // allVersions includes all regular versions of JSON Schema.
    59  // It does not include OpenAPI v3.0
    60  const allVersions = versionSet(1<<numJSONSchemaVersions-1) &^ (1 << VersionUnknown)
    61  
    62  // contains reports whether m contains the version v.
    63  func (m versionSet) contains(v Version) bool {
    64  	return (m & vset(v)) != 0
    65  }
    66  
    67  // vset returns the version set containing exactly v.
    68  func vset(v Version) versionSet {
    69  	return 1 << v
    70  }
    71  
    72  // vfrom returns the set of all versions starting at v.
    73  func vfrom(v Version) versionSet {
    74  	return allVersions &^ (vset(v) - 1)
    75  }
    76  
    77  // vbetween returns the set of all versions between
    78  // v0 and v1 inclusive.
    79  func vbetween(v0, v1 Version) versionSet {
    80  	return vfrom(v0) & vto(v1)
    81  }
    82  
    83  // vto returns the set of all versions up to
    84  // and including v.
    85  func vto(v Version) versionSet {
    86  	return allVersions & (vset(v+1) - 1)
    87  }
    88  
    89  // ParseVersion parses a version URI that defines a JSON Schema version.
    90  func ParseVersion(sv string) (Version, error) {
    91  	// Ignore a trailing empty fragment: it's a common error
    92  	// to omit or supply such a fragment and it's not entirely
    93  	// clear whether comparison should or should not
    94  	// be sensitive to its presence or absence.
    95  	sv = strings.TrimSuffix(sv, "#")
    96  	// If this linear search is ever a performance issue, we could
    97  	// build a map, but it doesn't seem worthwhile for now.
    98  	for i := Version(1); i < numJSONSchemaVersions; i++ {
    99  		if sv == strings.TrimSuffix(i.String(), "#") {
   100  			return i, nil
   101  		}
   102  	}
   103  	return 0, fmt.Errorf("$schema URI not recognized")
   104  }