Documentation ¶
Index ¶
- Constants
- Variables
- type Array
- type Boolean
- type Builtin
- type BuiltinFunction
- type Closure
- type CompiledFunction
- type Environment
- type Error
- type Function
- type Hash
- type HashKey
- type HashPair
- type Hashable
- type Integer
- type Macro
- type Null
- type Object
- type ObjectType
- type Quote
- type ReturnValue
- type String
Constants ¶
const ( // INTEGER_OBJ is the Integer object type INTEGER_OBJ = "INTEGER" // STRING_OBJ is the String object type STRING_OBJ = "STRING" // BOOLEAN_OBJ is the Boolean object type BOOLEAN_OBJ = "BOOLEAN" // NULL_OBJ is the Null object type NULL_OBJ = "NULL" // RETURN_VALUE_OBJ is the Return Value object type RETURN_VALUE_OBJ = "RETURN_VALUE" // ERROR_OBJ is the error object ERROR_OBJ = "ERROR" // FUNCTION_OBJ is the function object type FUNCTION_OBJ = "FUNCTION" // BUILTIN_OBJ is the builtin function object type BUILTIN_OBJ = "BUILTIN" // ARRAY_OBJ is the list object type (keeping it named array for continuity with book) ARRAY_OBJ = "ARRAY" // HASH_OBJ is the hash object type HASH_OBJ = "HASH" // QUOTE_OBJ is the quote object type QUOTE_OBJ = "QUOTE" // MACRO_OBJ is the macro literal object type MACRO_OBJ = "MACRO" // COMPILED_FUNCTION_OBJ is the compiler funciton object type COMPILED_FUNCTION_OBJ = "COMPILED_FUNCTION_OBJ" // CLOSURE_OBJ is the closure object type CLOSURE_OBJ = "CLOSURE_OBJ" )
Variables ¶
var Builtins = []struct { Name string Builtin *Builtin }{ { "len", &Builtin{Fn: func(args ...Object) Object { if len(args) != 1 { return newError("wrong number of arguments. got=%d, want=1", len(args)) } switch arg := args[0].(type) { case *Array: return &Integer{Value: int64(len(arg.Elements))} case *String: return &Integer{Value: int64(len(arg.Value))} default: return newError("argument to `len` not supported, got %s", args[0].Type()) } }, }, }, { "puts", &Builtin{Fn: func(args ...Object) Object { for _, arg := range args { fmt.Println(arg.Inspect()) } return nil }, }, }, { "first", &Builtin{Fn: func(args ...Object) Object { if len(args) != 1 { return newError("wrong number of arguments. got=%d, want=1", len(args)) } if args[0].Type() != ARRAY_OBJ { return newError("argument to `first` must be ARRAY, got %s", args[0].Type()) } arr := args[0].(*Array) if len(arr.Elements) > 0 { return arr.Elements[0] } return nil }, }, }, { "last", &Builtin{Fn: func(args ...Object) Object { if len(args) != 1 { return newError("wrong number of arguments. got=%d, want=1", len(args)) } if args[0].Type() != ARRAY_OBJ { return newError("argument to `last` must be ARRAY, got %s", args[0].Type()) } arr := args[0].(*Array) length := len(arr.Elements) if length > 0 { return arr.Elements[length-1] } return nil }, }, }, { "rest", &Builtin{Fn: func(args ...Object) Object { if len(args) != 1 { return newError("wrong number of arguments. got=%d, want=1", len(args)) } if args[0].Type() != ARRAY_OBJ { return newError("argument to `rest` must be ARRAY, got %s", args[0].Type()) } arr := args[0].(*Array) length := len(arr.Elements) if length > 0 { newElements := make([]Object, length-1, length-1) copy(newElements, arr.Elements[1:length]) return &Array{Elements: newElements} } return nil }, }, }, { "push", &Builtin{Fn: func(args ...Object) Object { if len(args) != 2 { return newError("wrong number of arguments. got=%d, want=2", len(args)) } if args[0].Type() != ARRAY_OBJ { return newError("argument to `push` must be ARRAY, got %s", args[0].Type()) } arr := args[0].(*Array) length := len(arr.Elements) newElements := make([]Object, length+1, length+1) copy(newElements, arr.Elements) newElements[length] = args[1] return &Array{Elements: newElements} }, }, }, }
Functions ¶
This section is empty.
Types ¶
type Array ¶
type Array struct {
Elements []Object
}
func (*Array) Type ¶
func (ao *Array) Type() ObjectType
type Boolean ¶
type Boolean struct {
Value bool
}
Boolean is the boolean type and used to represent boolean literals and holds an interval bool value
type Builtin ¶
type Builtin struct {
Fn BuiltinFunction
}
func GetBuiltinByName ¶
func (*Builtin) Type ¶
func (b *Builtin) Type() ObjectType
type BuiltinFunction ¶
type Closure ¶
type Closure struct { Fn *CompiledFunction Free []Object }
func (*Closure) Type ¶
func (c *Closure) Type() ObjectType
type CompiledFunction ¶
type CompiledFunction struct { Instructions code.Instructions NumLocals int NumParameters int }
func (*CompiledFunction) Inspect ¶
func (cf *CompiledFunction) Inspect() string
func (*CompiledFunction) Type ¶
func (cf *CompiledFunction) Type() ObjectType
type Environment ¶
type Environment struct {
// contains filtered or unexported fields
}
func NewEnclosedEnvironment ¶
func NewEnclosedEnvironment(outer *Environment) *Environment
func NewEnvironment ¶
func NewEnvironment() *Environment
type Error ¶
type Error struct {
Message string
}
Error is the base struct of our Error type
func (*Error) Type ¶
func (e *Error) Type() ObjectType
type Function ¶
type Function struct { Parameters []*ast.Identifier Body *ast.BlockStatement Env *Environment }
func (*Function) Type ¶
func (f *Function) Type() ObjectType
type HashKey ¶
type HashKey struct { Type ObjectType Value uint64 }
type Integer ¶
type Integer struct {
Value int64
}
Integer is the integer type used to represent integer literals and holds an internal int64 value
type Macro ¶
type Macro struct { Parameters []*ast.Identifier Body *ast.BlockStatement Env *Environment }
func (*Macro) Type ¶
func (m *Macro) Type() ObjectType
type Null ¶
type Null struct{}
Null is the null type and used to represent the absence of a value
type Object ¶
type Object interface { Type() ObjectType Inspect() string }
Object represents a value and implementations are expected to implement `Type()` and `Inspect()` functions
type ReturnValue ¶
type ReturnValue struct {
Value Object
}
ReturnValue is the return type and used to hold the value of another object. This is used for `return` statements and this object is tracked through the evalulator and when encountered stops evaluation of the program, or body of a function.
func (*ReturnValue) Inspect ¶
func (rv *ReturnValue) Inspect() string
Inspect returns a stringified version of the object for debugging
func (*ReturnValue) Type ¶
func (rv *ReturnValue) Type() ObjectType
Type returns the type of the object