Add parsing postprocessing functions and better doc comments

cfger.go

@@ -59,8 +59,6 @@ var indexedPartRegexp = regexp.MustCompile(`(?m)([a-zA-Z]+)(?:\[(\d+)\])?`)
 //	 - beta: "hello"
 func (cl *ConfigLoader) Get(key string) OptionalItem {
 	// httpcore[2].bananas
-	cl.lastKey = key
-
 	parts := strings.Split(key, ".")
 	var cursor any = cl.rawConfigFileContents
 	for _, part := range parts {
@@ -87,9 +85,8 @@ func (cl *ConfigLoader) Get(key string) OptionalItem {
 	return OptionalItem{key, cursor, true}
 }
 
+// GetEnv gets a given key from the environment variables.
 func (cl *ConfigLoader) GetEnv(envKey string) OptionalItem {
-	cl.lastKey = envKey
-
 	ev := os.Getenv(envKey)
 
 	if ev == "" {
@@ -98,28 +95,3 @@ func (cl *ConfigLoader) GetEnv(envKey string) OptionalItem {
 
 	return OptionalItem{envKey, ev, true}
 }
-
-// Required gets a given key from the currently loaded configuration and raises
-// a fatal error if it cannot be found.
-//
-// See documentation for Get for key format.
-func (cl *ConfigLoader) Required(key string) OptionalItem {
-	opt := cl.Get(key)
-	if !opt.found {
-		FatalErrorHandler(fmt.Errorf("required key %s not found in config file", key))
-		os.Exit(1)
-	}
-	return opt
-}
-
-// WithDefault gets a given key from the currently loaded configuration and
-// returns a default value if it cannot be found.
-//
-// See documentation for Get for key format.
-func (cl *ConfigLoader) WithDefault(key string, defaultValue any) OptionalItem {
-	opt := cl.Get(key)
-	if !opt.found {
-		return OptionalItem{item: defaultValue, found: true}
-	}
-	return opt
-}

types.go

@@ -1,11 +1,36 @@
 package cfger
 
+import (
+	"fmt"
+	"os"
+	"strconv"
+)
+
 type OptionalItem struct {
 	key   string
 	item  any
 	found bool
 }
 
+// Required raises a fatal error if the item is not present
+func (x OptionalItem) Required() OptionalItem {
+	if !x.found {
+		FatalErrorHandler(fmt.Errorf("required key %s not found in config", x.key))
+		os.Exit(1)
+	}
+	return x
+}
+
+// WithDefault returns the value if it is present, otherwise it returns the provided default value.
+func (x OptionalItem) WithDefault(val any) OptionalItem {
+	if !x.found {
+		x.item = val
+		x.found = true
+	}
+	return x
+}
+
+// AsInt returns the value of x as an integer, or 0 if no value is present.
 func (x OptionalItem) AsInt() int {
 	if !x.found {
 		return 0
@@ -13,6 +38,28 @@ func (x OptionalItem) AsInt() int {
 	return x.item.(int)
 }
 
+// ToInt parses x as an integer from a string and returns its value. If no value is present, 0 is returned, and if x is
+// unparseable, a fatal error is raised.
+func (x OptionalItem) ToInt() int {
+	if !x.found {
+		return 0
+	}
+
+	v, ok := x.item.(string)
+	if !ok {
+		FatalErrorHandler(fmt.Errorf("cfger: expected %s to be a string, got %T", x.key, x.item))
+		os.Exit(1)
+	}
+
+	iv, err := strconv.Atoi(v)
+	if err != nil {
+		FatalErrorHandler(fmt.Errorf("cfger: unable to parse %s as an integer: %w", x.key, err))
+	}
+
+	return iv
+}
+
+// AsString returns the value of x as a string, or an empty string if no value is present.
 func (x OptionalItem) AsString() string {
 	if !x.found {
 		return ""
@@ -20,9 +67,31 @@ func (x OptionalItem) AsString() string {
 	return x.item.(string)
 }
 
+// AsBool returns the value of x as a boolean, or an empty string if no value is present.
 func (x OptionalItem) AsBool() bool {
 	if !x.found {
 		return false
 	}
 	return x.item.(bool)
 }
+
+// ToBool parses x as a boolean from a string and returns its value. If no value is present, false is returned, and if x
+// is unparseable, a fatal error is raised.
+func (x OptionalItem) ToBool() bool {
+	if !x.found {
+		return false
+	}
+
+	v, ok := x.item.(string)
+	if !ok {
+		FatalErrorHandler(fmt.Errorf("cfger: expected %s to be a string, got %T", x.key, x.item))
+		os.Exit(1)
+	}
+
+	iv, err := strconv.ParseBool(v)
+	if err != nil {
+		FatalErrorHandler(fmt.Errorf("cfger: unable to parse %s as an boolean: %w", x.key, err))
+	}
+
+	return iv
+}