github.com/m3db/m3@v1.5.0/src/m3ninx/search/query/util.go (about)

     1  // Copyright (c) 2018 Uber Technologies, Inc.
     2  //
     3  // Permission is hereby granted, free of charge, to any person obtaining a copy
     4  // of this software and associated documentation files (the "Software"), to deal
     5  // in the Software without restriction, including without limitation the rights
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     7  // copies of the Software, and to permit persons to whom the Software is
     8  // furnished to do so, subject to the following conditions:
     9  //
    10  // The above copyright notice and this permission notice shall be included in
    11  // all copies or substantial portions of the Software.
    12  //
    13  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    14  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    15  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    16  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    17  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    18  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    19  // THE SOFTWARE.
    20  
    21  package query
    22  
    23  import (
    24  	"strings"
    25  
    26  	"github.com/m3db/m3/src/m3ninx/search"
    27  )
    28  
    29  const (
    30  	separator         = ", "
    31  	negationPrefix    = "negation("
    32  	negationSeparator = "), negation("
    33  	negationPostfix   = ")"
    34  )
    35  
    36  // singular returns a bool indicating whether a given query is composed of a single
    37  // query and returns that query if so.
    38  func singular(q search.Query) (search.Query, bool) {
    39  	switch q := q.(type) {
    40  	case *ConjuctionQuery:
    41  		if len(q.queries) == 1 {
    42  			return q.queries[0], true
    43  		}
    44  		return nil, false
    45  	case *DisjuctionQuery:
    46  		if len(q.queries) == 1 {
    47  			return q.queries[0], true
    48  		}
    49  		return nil, false
    50  	}
    51  	return q, true
    52  }
    53  
    54  // join concatenates a slice of queries.
    55  func join(b *strings.Builder, qs []search.Query) {
    56  	switch len(qs) {
    57  	case 0:
    58  		return
    59  	case 1:
    60  		b.WriteString(qs[0].String())
    61  		return
    62  	}
    63  
    64  	b.WriteString(qs[0].String())
    65  	for _, q := range qs[1:] {
    66  		b.WriteString(separator)
    67  		b.WriteString(q.String())
    68  	}
    69  }
    70  
    71  // joinNegation concatenates a slice of negated queries.
    72  func joinNegation(b *strings.Builder, qs []search.Query) {
    73  	switch len(qs) {
    74  	case 0:
    75  		return
    76  	case 1:
    77  		b.WriteString(negationPrefix)
    78  		b.WriteString(qs[0].String())
    79  		b.WriteString(negationPostfix)
    80  		return
    81  	}
    82  
    83  	b.WriteString(negationPrefix)
    84  	b.WriteString(qs[0].String())
    85  	for _, q := range qs[1:] {
    86  		b.WriteString(negationSeparator)
    87  		b.WriteString(q.String())
    88  	}
    89  
    90  	b.WriteString(negationPostfix)
    91  }