kythe.io@v0.0.68-0.20240422202219-7225dbc01741/kythe/go/util/schema/edges/edges.go (about)

     1  /*
     2   * Copyright 2016 The Kythe Authors. All rights reserved.
     3   *
     4   * Licensed under the Apache License, Version 2.0 (the "License");
     5   * you may not use this file except in compliance with the License.
     6   * You may obtain a copy of the License at
     7   *
     8   *   http://www.apache.org/licenses/LICENSE-2.0
     9   *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.
    15   */
    16  
    17  // Package edges defines constants for Kythe edges.
    18  package edges // import "kythe.io/kythe/go/util/schema/edges"
    19  
    20  import (
    21  	"regexp"
    22  	"strconv"
    23  	"strings"
    24  
    25  	"kythe.io/kythe/go/util/schema"
    26  )
    27  
    28  // Prefix defines the common prefix for all Kythe edge kinds.
    29  const Prefix = schema.Prefix + "edge/"
    30  
    31  // Edge kind labels
    32  const (
    33  	ChildOf                 = Prefix + "childof"
    34  	Denotes                 = Prefix + "denotes"
    35  	Extends                 = Prefix + "extends"
    36  	ExtendsPrivate          = Prefix + "extends/private"
    37  	ExtendsPrivateVirtual   = Prefix + "extends/private/virtual"
    38  	ExtendsProtected        = Prefix + "extends/protected"
    39  	ExtendsProtectedVirtual = Prefix + "extends/protected/virtual"
    40  	ExtendsPublic           = Prefix + "extends/public"
    41  	ExtendsPublicVirtual    = Prefix + "extends/public/virtual"
    42  	ExtendsVirtual          = Prefix + "extends/virtual"
    43  	Generates               = Prefix + "generates"
    44  	Named                   = Prefix + "named"
    45  	Overrides               = Prefix + "overrides"
    46  	OverridesTransitive     = Prefix + "overrides/transitive"
    47  	Param                   = Prefix + "param"
    48  	Satisfies               = Prefix + "satisfies"
    49  	TParam                  = Prefix + "tparam"
    50  	Typed                   = Prefix + "typed"
    51  )
    52  
    53  // Edge kinds associated with anchors
    54  const (
    55  	Defines         = Prefix + "defines"
    56  	DefinesBinding  = Prefix + "defines/binding"
    57  	Documents       = Prefix + "documents"
    58  	Ref             = Prefix + "ref"
    59  	RefCall         = Prefix + "ref/call"
    60  	RefCallImplicit = Prefix + "ref/call/implicit"
    61  	RefDoc          = Prefix + "ref/doc"
    62  	RefImplicit     = Prefix + "ref/implicit"
    63  	RefImports      = Prefix + "ref/imports"
    64  	RefInit         = Prefix + "ref/init"
    65  	RefInitImplicit = Prefix + "ref/init/implicit"
    66  	RefWrites       = Prefix + "ref/writes"
    67  	Tagged          = Prefix + "tagged"
    68  )
    69  
    70  // ParamIndex returns an edge label of the form "param.i" for the i given.
    71  func ParamIndex(i int) string { return Param + "." + strconv.Itoa(i) }
    72  
    73  // TParamIndex returns an edge label of the form "tparam.i" for the i given.
    74  func TParamIndex(i int) string { return TParam + "." + strconv.Itoa(i) }
    75  
    76  // revPrefix is used to distinguish reverse kinds from forward ones.
    77  const revPrefix = "%"
    78  
    79  // Mirror returns the opposite-directional edge label for kind.
    80  func Mirror(kind string) string {
    81  	if rev := strings.TrimPrefix(kind, revPrefix); rev != kind {
    82  		return rev
    83  	}
    84  	return revPrefix + kind
    85  }
    86  
    87  // Canonical returns the canonical forward version of an edge kind.
    88  func Canonical(kind string) string { return strings.TrimPrefix(kind, revPrefix) }
    89  
    90  // IsForward reports whether kind is a forward edge kind.
    91  func IsForward(kind string) bool { return !IsReverse(kind) }
    92  
    93  // IsReverse reports whether kind is a reverse edge kind.
    94  func IsReverse(kind string) bool { return strings.HasPrefix(kind, revPrefix) }
    95  
    96  // IsVariant reports whether x is equal to or a subkind of y.
    97  // For example, each of the following returns true:
    98  //
    99  //	IsVariant("/kythe/edge/defines/binding", "/kythe/edge/defines")
   100  //	IsVariant("/kythe/edge/defines", "/kythe/edge/defines")
   101  //
   102  // Moreover IsVariant(x, y) == IsVariant(Mirror(x), Mirror(y)) for all x, y.
   103  func IsVariant(x, y string) bool { return x == y || strings.HasPrefix(x, y+"/") }
   104  
   105  // IsAnchorEdge reports whether kind is one associated with anchors.
   106  func IsAnchorEdge(kind string) bool {
   107  	canon := Canonical(kind)
   108  	return IsVariant(canon, Defines) || IsVariant(canon, DefinesBinding) ||
   109  		IsVariant(canon, Documents) ||
   110  		IsVariant(canon, Ref) || IsVariant(canon, RefCall)
   111  }
   112  
   113  var ordinalKind = regexp.MustCompile(`^(.+)\.(\d+)$`)
   114  
   115  // ParseOrdinal reports whether kind has an ordinal suffix (.nnn), and if so,
   116  // returns the value of the ordinal as an integer. If not, the original kind is
   117  // returned as written and ordinal == 0.
   118  func ParseOrdinal(kind string) (base string, ordinal int, hasOrdinal bool) {
   119  	m := ordinalKind.FindStringSubmatch(kind)
   120  	if m == nil {
   121  		return kind, 0, false
   122  	}
   123  	ordinal, _ = strconv.Atoi(m[2])
   124  	return m[1], ordinal, true
   125  }
   126  
   127  // OrdinalKind reports whether kind (which does not have an ordinal suffix)
   128  // generally has an associated ordinal (e.g. /kythe/edge/param edges).
   129  func OrdinalKind(kind string) bool {
   130  	switch Canonical(kind) {
   131  	case Param:
   132  		return true
   133  	default:
   134  		return false
   135  	}
   136  }