melrōse musical expression player

package dsl import ( "fmt" "reflect" "sort" "strings" "sync" "github.com/emicklei/melrose/core" "github.com/emicklei/melrose/notify" ) // VariableStore is an in-memory storage of values by name. // Access to this store is go-routine safe. type VariableStore struct { mutex sync.RWMutex variables map[string]any } // NewVariableStore returns a new func NewVariableStore() *VariableStore { return &VariableStore{ variables: map[string]any{"_": core.EmptySequence}, } } func (v *VariableStore) getVariable(name string) variable { return variable{Name: name, store: v} } // NameFor finds the entry for a value and returns its (first) associated name func (v *VariableStore) NameFor(value any) string { v.mutex.RLock() defer v.mutex.RUnlock() for k, v := range v.variables { if reflect.DeepEqual(value, v) { // the first found return k } } return "" // not found } // Get returns a value found by the key. Inspect the second return value of presence. func (v *VariableStore) Get(key string) (any, bool) { v.mutex.RLock() e, ok := v.variables[key] v.mutex.RUnlock() return e, ok } // Put stores a value by the key. Overwrites any existing value. func (v *VariableStore) Put(key string, value any) { v.mutex.Lock() v.variables[key] = value v.mutex.Unlock() } // Delete removes a stored value by the key. Ignores if the key is not found. func (v *VariableStore) Delete(key string) { v.mutex.Lock() delete(v.variables, key) v.mutex.Unlock() } // Variables returns a copy of all stores variables. func (v *VariableStore) Variables() map[string]any { v.mutex.RLock() copy := map[string]any{} for k, v := range v.variables { copy[k] = v } v.mutex.RUnlock() return copy } // ListVariables prints a list of sorted key=value pairs. func ListVariables(storage core.VariableStorage, args []string) notify.Message { keys := []string{} width := 0 variables := storage.Variables() for k := range variables { // if filtering is wanted if len(args) == 1 && !strings.HasPrefix(k, args[0]) { continue } if len(k) > width { width = len(k) } keys = append(keys, k) } sort.Strings(keys) for _, k := range keys { v := variables[k] // skip empty temporary var if k == "_" { continue } if s, ok := v.(core.Storable); ok { fmt.Printf("%s = %s\n", strings.Repeat(" ", width-len(k))+k, s.Storex()) } else { fmt.Printf("%s = (%T) %v\n", strings.Repeat(" ", width-len(k))+k, v, v) } } return nil }