package objects import ( "strconv" "github.com/d5/tengo/compiler/token" ) // String represents a string value. type String struct { Value string runeStr []rune } // TypeName returns the name of the type. func (o *String) TypeName() string { return "string" } func (o *String) String() string { return strconv.Quote(o.Value) } // BinaryOp returns another object that is the result of // a given binary operator and a right-hand side object. func (o *String) BinaryOp(op token.Token, rhs Object) (Object, error) { switch op { case token.Add: switch rhs := rhs.(type) { case *String: return &String{Value: o.Value + rhs.Value}, nil default: return &String{Value: o.Value + rhs.String()}, nil } } return nil, ErrInvalidOperator } // IsFalsy returns true if the value of the type is falsy. func (o *String) IsFalsy() bool { return len(o.Value) == 0 } // Copy returns a copy of the type. func (o *String) Copy() Object { return &String{Value: o.Value} } // Equals returns true if the value of the type // is equal to the value of another object. func (o *String) Equals(x Object) bool { t, ok := x.(*String) if !ok { return false } return o.Value == t.Value } // IndexGet returns a character at a given index. func (o *String) IndexGet(index Object) (res Object, err error) { intIdx, ok := index.(*Int) if !ok { err = ErrInvalidIndexType return } idxVal := int(intIdx.Value) if o.runeStr == nil { o.runeStr = []rune(o.Value) } if idxVal < 0 || idxVal >= len(o.runeStr) { res = UndefinedValue return } res = &Char{Value: o.runeStr[idxVal]} return } // Iterate creates a string iterator. func (o *String) Iterate() Iterator { if o.runeStr == nil { o.runeStr = []rune(o.Value) } return &StringIterator{ v: o.runeStr, l: len(o.runeStr), } }