Add FindByAttrs

find_attrs.go

@@ -0,0 +1,75 @@
+package structural
+
+import (
+	"cuelang.org/go/cue"
+)
+
+var xx struct{}
+
+// FindByAttrs finds values in s if
+// 1) attrs : it has @attr(...)
+// 2) attrsK : it has @attr(key,...) [it must have all keys in the passed list, not just one]
+// 3) attrsKV : it has @attr(key=value,...) [it must have all key=value in the passed map, not just one of them]
+func FindByAttrs(s cue.Value, attrs []string, attrsK map[string][]string, attrsKV map[string]map[string]string) ([]cue.Value, error) {
+	out := make([]cue.Value, 0)
+
+	siter, err := s.Fields()
+	if err != nil {
+		return nil, err
+	}
+
+	attrsSet := make(map[string]struct{})
+	for _, a := range attrs {
+		attrsSet[a] = xx
+	}
+
+	for siter.Next() {
+		// label := siter.Label()
+		value := siter.Value()
+		attrs := value.Attributes()
+		for k, attr := range attrs {
+			if _, ok := attrsSet[k]; ok {
+				out = append(out, value)
+				break
+			}
+			if ks, ok := attrsK[k]; ok {
+				include := true
+				for _, checkKey := range ks {
+					// TODO API is lacking here, assume we have less than 20 attribute val positions...
+					found := false
+					for i := 0; i < 20; i++ {
+						key, err := attr.String(i)
+						if err == nil && key == checkKey {
+							found = true
+							break
+						}
+					}
+					if !found {
+						include = false
+						break
+					}
+				}
+				if include {
+					out = append(out, value)
+					break
+				}
+			}
+			if kvs, ok := attrsKV[k]; ok {
+				include := true
+				for checkKey, checkVal := range kvs {
+					val, found, err := attr.Lookup(0, checkKey)
+					if !found || err != nil || val != checkVal {
+						include = false
+						break
+					}
+				}
+				if include {
+					out = append(out, value)
+					break
+				}
+			}
+		}
+	}
+
+	return out, nil
+}

find_attrs_test.go

@@ -0,0 +1,52 @@
+package structural_test
+
+import (
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/suite"
+
+	"github.com/hofstadter-io/structural"
+
+	"cuelang.org/go/cue"
+)
+
+type FindAttrsTestSuite struct {
+	suite.Suite
+
+	findAttrsRT *structural.CueRuntime
+}
+
+func (suit *FindAttrsTestSuite) TestFindAttrs() {
+	var r cue.Runtime
+	input := `
+a: 2
+b: _ @findme(hide=true)        // 1
+b: 2
+c: 2
+d: _ @findme(hide=false)       // 2
+d: 3
+x: _ @andme()                  // 3
+xx: _ @check(this=isthis)      // 4
+xx1: _ @check(a,this=isthis)   // 5
+xxy: _ @check(this=notthat)
+xxz: _ @check(this)
+abc: _ @hasthis(needs,these)   // 6
+abd: _ @hasthis(a,needs,these) // 7
+abb: _ @hasthis(eeds,hese)
+`
+	i, err := r.Compile("", input)
+	assert.Nil(suit.T(), err)
+	v := i.Value()
+	assert.Nil(suit.T(), v.Err())
+	vs, err := structural.FindByAttrs(v,
+		[]string{"findme", "andme"},
+		map[string][]string{
+			"hasthis": []string{"needs", "these"},
+		},
+		map[string]map[string]string{
+			"check": map[string]string{
+				"this": "isthis",
+			},
+		})
+	assert.Nil(suit.T(), err)
+	assert.Len(suit.T(), vs, 7)
+}

structural_test.go

@@ -19,6 +19,7 @@ func TestStructuralTestSuite(t *testing.T) {
 	suite.Run(t, new(MaskTestSuite))
 	suite.Run(t, new(PickTestSuite))
 	suite.Run(t, new(QueryTestSuite))
+	suite.Run(t, new(FindAttrsTestSuite))
 
 }