160 lines
2.8 KiB
Go
160 lines
2.8 KiB
Go
package ast
|
|
|
|
import (
|
|
"bytes"
|
|
"monkey/token"
|
|
)
|
|
|
|
type Node interface {
|
|
TokenLiteral() string
|
|
String() string
|
|
}
|
|
|
|
type Statement interface {
|
|
Node
|
|
statementNode()
|
|
}
|
|
|
|
type Expression interface {
|
|
Node
|
|
expressionNode()
|
|
}
|
|
|
|
type Program struct {
|
|
Statements []Statement
|
|
}
|
|
|
|
func (p *Program) TokenLiteral() string {
|
|
if len(p.Statements) > 0 {
|
|
return p.Statements[0].TokenLiteral()
|
|
} else {
|
|
return ""
|
|
}
|
|
}
|
|
|
|
func (p *Program) String() string {
|
|
var out bytes.Buffer
|
|
|
|
for _, s := range p.Statements {
|
|
out.WriteString(s.String())
|
|
}
|
|
|
|
return out.String()
|
|
}
|
|
|
|
type Identifier struct {
|
|
Token token.Token // the token.Ident token
|
|
Value string
|
|
}
|
|
|
|
type LetStatement struct {
|
|
Token token.Token // the token.Let token
|
|
Name *Identifier
|
|
Value Expression
|
|
}
|
|
|
|
type ReturnStatement struct {
|
|
Token token.Token // the 'return token
|
|
ReturnValue Expression
|
|
}
|
|
|
|
type ExpressionStatement struct {
|
|
Token token.Token // the first token of the expression
|
|
Expression Expression
|
|
}
|
|
|
|
type IntegerLiteral struct {
|
|
Token token.Token
|
|
Value int64
|
|
}
|
|
|
|
type PrefixExpression struct {
|
|
Token token.Token
|
|
Operator string
|
|
Right Expression
|
|
}
|
|
|
|
func (ls *LetStatement) statementNode() {
|
|
}
|
|
func (ls *LetStatement) TokenLiteral() string {
|
|
return ls.Token.Literal
|
|
}
|
|
func (ls *LetStatement) String() string {
|
|
var out bytes.Buffer
|
|
|
|
out.WriteString(ls.TokenLiteral() + " ")
|
|
out.WriteString(ls.Name.String())
|
|
out.WriteString(" = ")
|
|
|
|
if ls.Value != nil {
|
|
out.WriteString(ls.Value.String())
|
|
}
|
|
|
|
out.WriteString(";")
|
|
|
|
return out.String()
|
|
}
|
|
|
|
func (i *Identifier) expressionNode() {
|
|
}
|
|
func (i *Identifier) TokenLiteral() string {
|
|
return i.Token.Literal
|
|
}
|
|
func (i *Identifier) String() string { return i.Value }
|
|
|
|
func (rs *ReturnStatement) statementNode() {
|
|
}
|
|
func (rs *ReturnStatement) TokenLiteral() string {
|
|
return rs.Token.Literal
|
|
}
|
|
func (rs *ReturnStatement) String() string {
|
|
var out bytes.Buffer
|
|
|
|
out.WriteString(rs.TokenLiteral() + " ")
|
|
|
|
if rs.ReturnValue != nil {
|
|
out.WriteString(rs.ReturnValue.String())
|
|
}
|
|
|
|
out.WriteString(";")
|
|
|
|
return out.String()
|
|
}
|
|
|
|
func (es *ExpressionStatement) statementNode() {
|
|
}
|
|
func (es *ExpressionStatement) TokenLiteral() string {
|
|
return es.Token.Literal
|
|
}
|
|
func (es *ExpressionStatement) String() string {
|
|
if es.Expression != nil {
|
|
return es.Expression.String()
|
|
}
|
|
|
|
return ""
|
|
}
|
|
|
|
func (il *IntegerLiteral) expressionNode() {
|
|
}
|
|
func (il *IntegerLiteral) TokenLiteral() string {
|
|
return il.Token.Literal
|
|
}
|
|
func (il *IntegerLiteral) String() string {
|
|
return il.Token.Literal
|
|
}
|
|
|
|
func (pe *PrefixExpression) expressionNode() {}
|
|
func (pe *PrefixExpression) TokenLiteral() string {
|
|
return pe.Token.Literal
|
|
}
|
|
func (pe *PrefixExpression) String() string {
|
|
var out bytes.Buffer
|
|
|
|
out.WriteString("(")
|
|
out.WriteString(pe.Operator)
|
|
out.WriteString(pe.Right.String())
|
|
out.WriteString(")")
|
|
|
|
return out.String()
|
|
}
|