Made variables not copy on usage and cleaned up merge

models/cacao/variables.go

@@ -10,34 +10,36 @@ import (
 // Allows passing in multiple variables at once
 func NewVariables(new ...Variable) Variables {
 	variables := make(Variables)
-	variables.InsertRange(new...)
+	for _, variable := range new {
+		variables.Insert(variable)
+	}
 	return variables
 }
 
 // Insert a variable
 //
 // Returns true if the variable was inserted
-func (variables Variables) Insert(new Variable) bool {
-	if _, found := variables[new.Name]; found {
+func (variables *Variables) Insert(new Variable) bool {
+	if _, found := (*variables)[new.Name]; found {
 		return false
 	}
-	variables[new.Name] = new
+	(*variables)[new.Name] = new
 	return true
 }
 
 // Insert or replace a variable
 //
 // Returns true if the variable was replaced
-func (variables Variables) InsertOrReplace(new Variable) bool {
-	_, found := variables[new.Name]
-	variables[new.Name] = new
+func (variables *Variables) InsertOrReplace(new Variable) bool {
+	_, found := (*variables)[new.Name]
+	(*variables)[new.Name] = new
 	return found
 }
 
-// Insert multiple variables at once
-func (variables Variables) InsertRange(new ...Variable) {
-	for _, newVar := range new {
-		variables.Insert(newVar)
+// Insert variables map at once into the base and keep base variables in favor of source duplicates
+func (variables *Variables) InsertRange(source Variables) {
+	for _, variable := range source {
+		variables.Insert(variable)
 	}
 }
 
@@ -49,29 +51,22 @@ func (variables Variables) Find(key string) (Variable, bool) {
 	return val, ok
 }
 
-// Construct a Replacer for string interpolation
+// Interpolate variable references into a target string
 //
-// Variable substitution is performed according to the CACAO spec,
-// which states `__var__:value` is replaced with the value of `__var__`.
-func (variables Variables) Replacer() *strings.Replacer {
+// Returns the Interpolated string with variables values available in the map
+func (variables *Variables) Interpolate(input string) string {
 	replacements := make([]string, 0)
-	for key, value := range variables {
-		replacementKey := fmt.Sprintf("%s:value", key)
+	for key, value := range *variables {
+		replacementKey := fmt.Sprint(key, ":value")
 		replacements = append(replacements, replacementKey, value.Value)
 	}
-	return strings.NewReplacer(replacements...)
-}
-
-// Interpolate variable references in a string
-func (variables Variables) Interpolate(s string) string {
-	replacer := variables.Replacer()
-	return replacer.Replace(s)
+	return strings.NewReplacer(replacements...).Replace(input)
 }
 
 // Select a subset of variables from the map
 //
 // Unknown keys are ignored.
-func (variables Variables) Select(keys []string) Variables {
+func (variables *Variables) Select(keys []string) Variables {
 	newVariables := NewVariables()
 
 	for _, key := range keys {
@@ -83,16 +78,9 @@ func (variables Variables) Select(keys []string) Variables {
 	return newVariables
 }
 
-// Merge two maps of Cacao variables
-func (variables Variables) Merge(new Variables) Variables {
-	combined := NewVariables()
-	for _, value := range variables {
-		combined.Insert(value)
+// Merge two maps of Cacao variables and replace the base with the source if exists
+func (variables *Variables) Merge(source Variables) {
+	for _, variable := range source {
+		variables.InsertOrReplace(variable)
 	}
-
-	for _, newValue := range new {
-		combined.InsertOrReplace(newValue)
-	}
-
-	return combined
 }