basic HTTP api and uistate.

internal/color/color.go

@@ -1,6 +1,7 @@
 package color
 
 import (
+	"encoding/json"
 	"fmt"
 	"github.com/lucasb-eyer/go-colorful"
 	"math"
@@ -15,6 +16,21 @@ type Color struct {
 	XY  *XY     `json:"xy,omitempty"`
 }
 
+func (col *Color) MarshalJSON() ([]byte, error) {
+	return json.Marshal(col.String())
+}
+
+func (col *Color) UnmarshalJSON(bytes []byte) error {
+	var s string
+	err := json.Unmarshal(bytes, &s)
+	if err != nil {
+		return err
+	}
+
+	*col, err = Parse(s)
+	return err
+}
+
 func (col *Color) IsHueSat() bool {
 	return col.HS != nil
 }

internal/gentools/update.go

@@ -0,0 +1,66 @@
+package gentools
+
+func ApplyUpdate[T any](dst *T, value *T) {
+	if value != nil {
+		*dst = *value
+	}
+}
+
+func ApplyUpdatePtr[T any](dst **T, value *T) {
+	if value != nil {
+		*dst = ShallowCopy(value)
+	}
+}
+
+func ApplyUpdateSlice[T any](dst *[]T, value []T) {
+	if value != nil {
+		*dst = append([]T{}, value...)
+	}
+}
+
+func ApplyUpdateNonZero[T comparable](dst *T, value *T) {
+	var zero T
+	if value != nil && *value != zero {
+		*dst = *value
+	}
+}
+
+func ApplyUpdateNilZero[T comparable](dst **T, value *T) {
+	if value != nil {
+		var zero T
+
+		if *value == zero {
+			*dst = nil
+		} else {
+			valueCopy := *value
+			*dst = &valueCopy
+		}
+	}
+}
+
+func ApplyMapUpdate[K comparable, V any](dst *map[K]V, src map[K]*V) {
+	if *dst == nil {
+		dst = &map[K]V{}
+	}
+	for key, value := range src {
+		if value != nil {
+			(*dst)[key] = *value
+		} else {
+			delete(*dst, key)
+		}
+	}
+}
+
+func ApplyUpdateMapNilZero[K comparable, V comparable](dst *map[K]V, src map[K]V) {
+	var zero V
+	if *dst == nil {
+		dst = &map[K]V{}
+	}
+	for key, value := range src {
+		if value != zero {
+			(*dst)[key] = value
+		} else {
+			delete(*dst, key)
+		}
+	}
+}