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119 lines
2.4 KiB
Go
119 lines
2.4 KiB
Go
package ast
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import (
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"fmt"
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)
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type Printer struct {
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}
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func NewPrinter() *Printer {
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return &Printer{}
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}
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func (ap *Printer) PrintStmts(stmts []Stmt) string {
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str := ""
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for _, stmt := range stmts {
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str += stmt.Accept(ap).(string) + "\n"
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}
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return str
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}
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func (ap *Printer) PrintExpr(expr Expr) string {
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return expr.Accept(ap).(string)
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}
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func (ap *Printer) VisitErrorStmt(stmt *ErrorStmt) any {
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return stmt.Value
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}
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func (ap *Printer) VisitExpressionStmt(stmt *ExpressionStmt) any {
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return stmt.Expression.Accept(ap)
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}
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func (ap *Printer) VisitPrintStmt(stmt *PrintStmt) any {
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return ap.parenthesizeExpr("print", stmt.Expression)
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}
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func (ap *Printer) VisitIfStmt(stmt *IfStmt) any {
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str := "(if"
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if stmt.Condition != nil {
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str += " " + stmt.Condition.Accept(ap).(string)
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}
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if stmt.ThenBranch != nil {
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str += " " + ap.bracesizeStmt(stmt.ThenBranch)
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}
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if stmt.ElseBranch != nil {
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str += " else " + ap.bracesizeStmt(stmt.ElseBranch)
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}
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return str + ")"
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}
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func (ap *Printer) VisitVarStmt(stmt *VarStmt) any {
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return ap.parenthesizeExpr("var", &LiteralExpr{stmt.Name}, stmt.Initializer)
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}
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func (ap *Printer) VisitBlockStmt(stmt *BlockStmt) any {
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return ap.bracesizeStmt(stmt.Statements...)
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}
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func (ap *Printer) VisitVariableExpr(expr *VariableExpr) any {
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return expr.Name.Lexeme
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}
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func (ap *Printer) VisitBinaryExpr(expr *BinaryExpr) any {
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return ap.parenthesizeExpr(expr.Operator.Lexeme, expr.Left, expr.Right)
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}
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func (ap *Printer) VisitGroupingExpr(expr *GroupingExpr) any {
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return ap.parenthesizeExpr("group", expr.Expression)
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}
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func (ap *Printer) VisitLiteralExpr(expr *LiteralExpr) any {
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if expr.Value == nil {
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return "nil"
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}
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return fmt.Sprint(expr.Value)
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}
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func (ap *Printer) VisitUnaryExpr(expr *UnaryExpr) any {
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return ap.parenthesizeExpr(expr.Operator.Lexeme, expr.Right)
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}
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func (ap *Printer) VisitErrorExpr(expr *ErrorExpr) any {
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return expr.Value
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}
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func (ap *Printer) VisitAssignExpr(expr *AssignExpr) any {
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return ap.parenthesizeExpr("=", &VariableExpr{expr.Name}, expr.Value)
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}
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func (ap *Printer) parenthesizeExpr(name string, exprs ...Expr) string {
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str := "(" + name
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for _, expr := range exprs {
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if expr == nil {
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continue
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}
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str += " " + expr.Accept(ap).(string)
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}
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return str + ")"
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}
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func (ap *Printer) bracesizeStmt(stmts ...Stmt) string {
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str := "{\n"
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for _, s := range stmts {
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str += " " + s.Accept(ap).(string) + "\n"
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}
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return str + "}"
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}
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