[pkg/ottl] Add new FloatLikeGetter and FloatGetter (#21896)

* add new getters

* changelog

* Add support for converting bool

* Add to function parser

* Add to floatgetter tests

* Add to floatgetter slice support

.chloggen/ottl-floatlikegetter.yaml

@@ -0,0 +1,16 @@
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: pkg/ottl
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Add `FloatLikeGetter` and `FloatGetter` to facilitate float retrival for functions.
+
+# One or more tracking issues related to the change
+issues: [21896]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:

pkg/ottl/expression.go

@@ -18,6 +18,7 @@ import (
 	"context"
 	"encoding/hex"
 	"fmt"
+	"strconv"
 
 	jsoniter "github.com/json-iterator/go"
 	"go.opentelemetry.io/collector/pdata/pcommon"
@@ -153,6 +154,10 @@ type IntGetter[K any] interface {
 	Get(ctx context.Context, tCtx K) (int64, error)
 }
 
+type FloatGetter[K any] interface {
+	Get(ctx context.Context, tCtx K) (float64, error)
+}
+
 type PMapGetter[K any] interface {
 	Get(ctx context.Context, tCtx K) (pcommon.Map, error)
 }
@@ -225,6 +230,70 @@ func (g StandardStringLikeGetter[K]) Get(ctx context.Context, tCtx K) (*string,
 	return &result, nil
 }
 
+// FloatLikeGetter is a Getter that returns a float64 by converting the underlying value to a float64 if necessary.
+type FloatLikeGetter[K any] interface {
+	// Get retrieves a float64 value.
+	// Unlike `FloatGetter`, the expectation is that the underlying value is converted to a float64 if possible.
+	// If the value cannot be converted to a float64, nil and an error are returned.
+	// If the value is nil, nil is returned without an error.
+	Get(ctx context.Context, tCtx K) (*float64, error)
+}
+
+type StandardFloatLikeGetter[K any] struct {
+	Getter func(ctx context.Context, tCtx K) (interface{}, error)
+}
+
+func (g StandardFloatLikeGetter[K]) Get(ctx context.Context, tCtx K) (*float64, error) {
+	val, err := g.Getter(ctx, tCtx)
+	if err != nil {
+		return nil, err
+	}
+	if val == nil {
+		return nil, nil
+	}
+	var result float64
+	switch v := val.(type) {
+	case float64:
+		result = v
+	case int64:
+		result = float64(v)
+	case string:
+		result, err = strconv.ParseFloat(v, 64)
+		if err != nil {
+			return nil, err
+		}
+	case bool:
+		if v {
+			result = float64(1)
+		} else {
+			result = float64(0)
+		}
+	case pcommon.Value:
+		switch v.Type() {
+		case pcommon.ValueTypeDouble:
+			result = v.Double()
+		case pcommon.ValueTypeInt:
+			result = float64(v.Int())
+		case pcommon.ValueTypeStr:
+			result, err = strconv.ParseFloat(v.Str(), 64)
+			if err != nil {
+				return nil, err
+			}
+		case pcommon.ValueTypeBool:
+			if v.Bool() {
+				result = float64(1)
+			} else {
+				result = float64(0)
+			}
+		default:
+			return nil, fmt.Errorf("unsupported value type: %v", v.Type())
+		}
+	default:
+		return nil, fmt.Errorf("unsupported type: %T", v)
+	}
+	return &result, nil
+}
+
 func (p *Parser[K]) newGetter(val value) (Getter[K], error) {
 	if val.IsNil != nil && *val.IsNil {
 		return &literal[K]{value: nil}, nil

pkg/ottl/expression_test.go

@@ -808,3 +808,166 @@ func Test_StandardStringLikeGetter(t *testing.T) {
 		})
 	}
 }
+
+func Test_StandardFloatLikeGetter(t *testing.T) {
+	tests := []struct {
+		name             string
+		getter           FloatLikeGetter[interface{}]
+		want             interface{}
+		valid            bool
+		expectedErrorMsg string
+	}{
+		{
+			name: "string type",
+			getter: StandardFloatLikeGetter[interface{}]{
+				Getter: func(ctx context.Context, tCtx interface{}) (interface{}, error) {
+					return "1.0", nil
+				},
+			},
+			want:  1.0,
+			valid: true,
+		},
+		{
+			name: "int64 type",
+			getter: StandardFloatLikeGetter[interface{}]{
+				Getter: func(ctx context.Context, tCtx interface{}) (interface{}, error) {
+					return int64(1), nil
+				},
+			},
+			want:  float64(1),
+			valid: true,
+		},
+		{
+			name: "float64 type",
+			getter: StandardFloatLikeGetter[interface{}]{
+				Getter: func(ctx context.Context, tCtx interface{}) (interface{}, error) {
+					return 1.1, nil
+				},
+			},
+			want:  1.1,
+			valid: true,
+		},
+		{
+			name: "float64 bool true",
+			getter: StandardFloatLikeGetter[interface{}]{
+				Getter: func(ctx context.Context, tCtx interface{}) (interface{}, error) {
+					return true, nil
+				},
+			},
+			want:  float64(1),
+			valid: true,
+		},
+		{
+			name: "float64 bool false",
+			getter: StandardFloatLikeGetter[interface{}]{
+				Getter: func(ctx context.Context, tCtx interface{}) (interface{}, error) {
+					return false, nil
+				},
+			},
+			want:  float64(0),
+			valid: true,
+		},
+		{
+			name: "pcommon.value type int",
+			getter: StandardFloatLikeGetter[interface{}]{
+				Getter: func(ctx context.Context, tCtx interface{}) (interface{}, error) {
+					v := pcommon.NewValueInt(int64(100))
+					return v, nil
+				},
+			},
+			want:  float64(100),
+			valid: true,
+		},
+		{
+			name: "pcommon.value type float",
+			getter: StandardFloatLikeGetter[interface{}]{
+				Getter: func(ctx context.Context, tCtx interface{}) (interface{}, error) {
+					v := pcommon.NewValueDouble(float64(1.1))
+					return v, nil
+				},
+			},
+			want:  1.1,
+			valid: true,
+		},
+		{
+			name: "pcommon.value type string",
+			getter: StandardFloatLikeGetter[interface{}]{
+				Getter: func(ctx context.Context, tCtx interface{}) (interface{}, error) {
+					v := pcommon.NewValueStr("1.1")
+					return v, nil
+				},
+			},
+			want:  1.1,
+			valid: true,
+		},
+		{
+			name: "pcommon.value type bool true",
+			getter: StandardFloatLikeGetter[interface{}]{
+				Getter: func(ctx context.Context, tCtx interface{}) (interface{}, error) {
+					v := pcommon.NewValueBool(true)
+					return v, nil
+				},
+			},
+			want:  float64(1),
+			valid: true,
+		},
+		{
+			name: "pcommon.value type bool false",
+			getter: StandardFloatLikeGetter[interface{}]{
+				Getter: func(ctx context.Context, tCtx interface{}) (interface{}, error) {
+					v := pcommon.NewValueBool(false)
+					return v, nil
+				},
+			},
+			want:  float64(0),
+			valid: true,
+		},
+		{
+			name: "nil",
+			getter: StandardFloatLikeGetter[interface{}]{
+				Getter: func(ctx context.Context, tCtx interface{}) (interface{}, error) {
+					return nil, nil
+				},
+			},
+			want:  nil,
+			valid: true,
+		},
+		{
+			name: "invalid type",
+			getter: StandardFloatLikeGetter[interface{}]{
+				Getter: func(ctx context.Context, tCtx interface{}) (interface{}, error) {
+					return []byte{}, nil
+				},
+			},
+			valid:            false,
+			expectedErrorMsg: "unsupported type: []uint8",
+		},
+		{
+			name: "invalid pcommon.Value type",
+			getter: StandardFloatLikeGetter[interface{}]{
+				Getter: func(ctx context.Context, tCtx interface{}) (interface{}, error) {
+					v := pcommon.NewValueMap()
+					return v, nil
+				},
+			},
+			valid:            false,
+			expectedErrorMsg: "unsupported value type: Map",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			val, err := tt.getter.Get(context.Background(), nil)
+			if tt.valid {
+				assert.NoError(t, err)
+				if tt.want == nil {
+					assert.Nil(t, val)
+				} else {
+					assert.Equal(t, tt.want, *val)
+				}
+			} else {
+				assert.EqualError(t, err, tt.expectedErrorMsg)
+			}
+		})
+	}
+}

pkg/ottl/functions.go

@@ -155,6 +155,18 @@ func (p *Parser[K]) buildSliceArg(argVal value, argType reflect.Type) (any, erro
 			return nil, err
 		}
 		return arg, nil
+	case strings.HasPrefix(name, "FloatGetter"):
+		arg, err := buildSlice[FloatGetter[K]](argVal, argType, p.buildArg, name)
+		if err != nil {
+			return nil, err
+		}
+		return arg, nil
+	case strings.HasPrefix(name, "FloatLikeGetter"):
+		arg, err := buildSlice[FloatLikeGetter[K]](argVal, argType, p.buildArg, name)
+		if err != nil {
+			return nil, err
+		}
+		return arg, nil
 	default:
 		return nil, fmt.Errorf("unsupported slice type '%s' for function", argType.Elem().Name())
 	}
@@ -193,6 +205,18 @@ func (p *Parser[K]) buildArg(argVal value, argType reflect.Type) (any, error) {
 			return nil, err
 		}
 		return StandardStringLikeGetter[K]{Getter: arg.Get}, nil
+	case strings.HasPrefix(name, "FloatGetter"):
+		arg, err := p.newGetter(argVal)
+		if err != nil {
+			return nil, err
+		}
+		return StandardTypeGetter[K, float64]{Getter: arg.Get}, nil
+	case strings.HasPrefix(name, "FloatLikeGetter"):
+		arg, err := p.newGetter(argVal)
+		if err != nil {
+			return nil, err
+		}
+		return StandardFloatLikeGetter[K]{Getter: arg.Get}, nil
 	case strings.HasPrefix(name, "IntGetter"):
 		arg, err := p.newGetter(argVal)
 		if err != nil {