126 lines
2.8 KiB
Java
126 lines
2.8 KiB
Java
package cd.ir;
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import cd.ir.Ast.Decl;
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import cd.ir.Ast.Expr;
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import cd.ir.Ast.Stmt;
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/**
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* A visitor that visits any kind of node
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*/
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public class AstVisitor<R, A> extends ExprVisitor<R, A> {
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/**
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* Recurse and process {@code ast}. It is preferred to
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* call this rather than calling accept directly, since
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* it can be overloaded to introduce memoization,
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* for example.
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*/
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public R visit(Ast ast, A arg) {
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return ast.accept(this, arg);
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}
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/**
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* Overrides {@link ExprVisitor#visitChildren(Expr, Object)} and
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* delegates to the more general {@link #visitChildren(Ast, Object)}
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* with {@link Ast} parameter. This method is final to prevent
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* overriding only one of the two versions.
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*/
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@Override
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public final R visitChildren(Expr ast, A arg) {
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return visitChildren((Ast) ast, arg);
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}
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/**
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* A handy function which visits the children of {@code ast},
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* providing "arg" to each of them. It returns the result of
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* the last child in the list. It is invoked by the method
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* {@link #dflt(Ast, Object)} by default.
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*/
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public R visitChildren(Ast ast, A arg) {
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R lastValue = null;
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for (Ast child : ast.children())
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lastValue = visit(child, arg);
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return lastValue;
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}
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/**
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* The default action for default actions is to call this,
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* which simply recurses to any children. Also called
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* by seq() by default.
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*/
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protected R dflt(Ast ast, A arg) {
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return visitChildren(ast, arg);
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}
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/**
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* The default action for statements is to call this
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*/
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protected R dfltStmt(Stmt ast, A arg) {
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return dflt(ast, arg);
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}
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/**
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* The default action for expressions is to call this
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*/
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@Override
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protected R dfltExpr(Expr ast, A arg) {
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return dflt(ast, arg);
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}
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/**
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* The default action for AST nodes representing declarations
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* is to call this function
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*/
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protected R dfltDecl(Decl ast, A arg) {
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return dflt(ast, arg);
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}
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public R assign(Ast.Assign ast, A arg) {
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return dfltStmt(ast, arg);
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}
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public R builtInWrite(Ast.BuiltInWrite ast, A arg) {
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return dfltStmt(ast, arg);
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}
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public R builtInWriteln(Ast.BuiltInWriteln ast, A arg) {
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return dfltStmt(ast, arg);
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}
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public R classDecl(Ast.ClassDecl ast, A arg) {
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return dfltDecl(ast, arg);
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}
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public R methodDecl(Ast.MethodDecl ast, A arg) {
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return dfltDecl(ast, arg);
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}
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public R varDecl(Ast.VarDecl ast, A arg) {
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return dfltDecl(ast, arg);
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}
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public R ifElse(Ast.IfElse ast, A arg) {
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return dfltStmt(ast, arg);
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}
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public R returnStmt(Ast.ReturnStmt ast, A arg) {
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return dfltStmt(ast, arg);
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}
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public R methodCall(Ast.MethodCall ast, A arg) {
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return dfltStmt(ast, arg);
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}
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public R nop(Ast.Nop ast, A arg) {
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return dfltStmt(ast, arg);
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}
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public R seq(Ast.Seq ast, A arg) {
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return dflt(ast, arg);
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}
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public R whileLoop(Ast.WhileLoop ast, A arg) {
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return dfltStmt(ast, arg);
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}
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}
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