Add Provider interface

cmd/stepd/main.go

@@ -76,7 +76,7 @@ func main () {
 	
 	// set up the environment
 	environment := step.Environment { }
-	environment.FuncProviders = providers.All()
+	environment.Providers = providers.All()
 	err = environment.Init(context.Background())
 	if err != nil { log.Fatal(err) }
 

environment.go

@@ -19,9 +19,10 @@ type Environment struct {
 	// FS, if specified, is the filesystem that this environment will load
 	// documents from. Its methods must be safe for concurrent execution.
 	FS fs.FS
-	// FuncProviders is a slice of FuncMap providers whoose functions will
+	// Providers is a slice of objects which can provide various
-	// be available to any documents this environment processes.
+	// functionality to the environment. In order to be used, values in this
-	FuncProviders []FuncProvider
+	// slice must implement one or more of the interfaces in provider.go.
+	Providers []Provider
 
 	documents usync.Locker[map[string] *Document]
 	funcMap template.FuncMap
@@ -31,7 +32,9 @@ type Environment struct {
 func (this *Environment) Init (ctx context.Context) error {
 	this.documents = usync.NewLocker(make(map[string] *Document))
 	this.funcMap = make(template.FuncMap)
-	for _, provider := range this.FuncProviders {
+	for _, provider := range this.Providers {
+		provider, ok := provider.(FuncProvider)
+		if !ok { continue }
 		funcMap := provider.FuncMap()
 		if funcMap == nil { continue }
 		for name, function := range funcMap {
@@ -127,7 +130,7 @@ func (this *Environment) parse (name string, modTime time.Time, input io.Reader)
 	for name, function := range this.funcMap {
 		funcMap[name] = function
 	}
-	for _, provider := range this.FuncProviders {
+	for _, provider := range this.Providers {
 		provider, ok := provider.(FuncProviderFor)
 		if !ok { continue }
 		funcMapFor := provider.FuncMapFor(document)

provider.go

@@ -2,8 +2,12 @@ package step
 
 import "html/template"
 
+// Provider is an object which provides extra functionality to an environment.
+type Provider any
+
 // FuncProvider provides a template.FuncMap.
 type FuncProvider interface {
+	Provider
 	// FuncMap provides a template.FuncMap. It may return nil, in which case
 	// its result is simply not considered.
 	FuncMap () template.FuncMap
@@ -12,7 +16,7 @@ type FuncProvider interface {
 // FuncProviderFor is an object that provides a template.FuncMap for a specific
 // document.
 type FuncProviderFor interface {
-	FuncProvider
+	Provider
 	// FuncMap provides a template.FuncMap, given a particular document. It
 	// may return nil, in which case its result is simply not considered.
 	FuncMapFor (*Document) template.FuncMap
@@ -20,6 +24,7 @@ type FuncProviderFor interface {
 
 // Configurable is an object that can be configured according to metadata.
 type Configurable interface {
+	Provider
 	// Configure uses config to configure the object. It must not modify
 	// config. Keys are namespaced with a '.' and are written in kebab case.
 	Configure (config Meta) error

providers/all.go

@@ -11,8 +11,8 @@ import fpimport   "git.tebibyte.media/sashakoshka/step/providers/import"
 import fpmarkdown "git.tebibyte.media/sashakoshka/step/providers/markdown"
 
 // All returns a slice of all providers defined in sub-packages.
-func All () []step.FuncProvider {
+func All () []step.Provider {
-	return []step.FuncProvider {
+	return []step.Provider {
 		new(fpos.Provider),
 		new(fphttp.Provider),
 		new(fppath.Provider),