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* Copyright (C) 2001 Chad Fowler <chadfowler@chadfowler.com>

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* Copyright (C) 2001-2004 Jan Arne Petersen <jpetersen@uni-bonn.de>

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* Copyright (C) 2002-2005 Thomas E Enebo <enebo@acm.org>

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package org.jruby;

import org.jruby.anno.JRubyClass;

import org.jruby.anno.JRubyMethod;

import org.jruby.exceptions.RaiseException;

import org.jruby.ext.ripper.RubyLexer;

import org.jruby.parser.StaticScope;

import org.jruby.runtime.Arity;

import org.jruby.runtime.Binding;

import org.jruby.runtime.Block;

import org.jruby.runtime.ClassIndex;

import org.jruby.runtime.DynamicScope;

import org.jruby.runtime.ThreadContext;

import org.jruby.runtime.Visibility;

import org.jruby.runtime.builtin.IRubyObject;

import org.jruby.runtime.marshal.DataType;

import static org.jruby.api.Convert.asBoolean;

import static org.jruby.api.Convert.asFixnum;

import static org.jruby.api.Create.newArray;

import static org.jruby.api.Create.newString;

import static org.jruby.api.Define.defineClass;

import static org.jruby.api.Error.nameError;

import static org.jruby.util.RubyStringBuilder.str;

@JRubyClass(name="Binding")

public class RubyBinding extends RubyObject implements DataType {

private Binding binding;

public RubyBinding(Ruby runtime, RubyClass rubyClass, Binding binding) {

super(runtime, rubyClass);

this.binding = binding;

}

private RubyBinding(Ruby runtime, RubyClass rubyClass) {

super(runtime, rubyClass);

}

public static RubyClass createBindingClass(ThreadContext context, RubyClass Object) {

return defineClass(context, "Binding", Object, RubyBinding::new).

reifiedClass(RubyBinding.class).

classIndex(ClassIndex.BINDING).

defineMethods(context, RubyBinding.class).

tap(c -> c.singletonClass(context).undefMethods(context, "new"));

}

public Binding getBinding() {

return binding;

}

// Proc class

public static RubyBinding newBinding(Ruby runtime, Binding binding) {

return new RubyBinding(runtime, runtime.getBinding(), binding);

}

@JRubyMethod(name = "initialize", visibility = Visibility.PRIVATE)

@Override

public IRubyObject initialize(ThreadContext context) {

binding = context.currentBinding();

return this;

}

@JRubyMethod

public IRubyObject dup(ThreadContext context) {

RubyBinding newBinding = newBinding(context.runtime, binding.dup(context));

copyInstanceVariablesInto(newBinding);

return newBinding;

}

@JRubyMethod(name = "initialize_copy", visibility = Visibility.PRIVATE)

public IRubyObject initialize_copy(ThreadContext context, IRubyObject other) {

binding = ((RubyBinding) other).binding.clone();

return this;

}

// c: bind_eval

@JRubyMethod(name = "eval", required = 1, optional = 2, checkArity = false)

public IRubyObject eval(ThreadContext context, IRubyObject[] args) {

int argc = Arity.checkArgumentCount(context, args, 1, 3);

IRubyObject[] newArgs = new IRubyObject[argc+1];

newArgs[0] = args[0]; // eval string

newArgs[1] = this; // binding

if (argc > 1) {

newArgs[2] = args[1]; // file

if (argc > 2) {

newArgs[3] = args[2]; // line

}

}

return RubyKernel.eval(context, this, newArgs, Block.NULL_BLOCK);

}

@JRubyMethod(name = "local_variable_defined?")

public IRubyObject local_variable_defined_p(ThreadContext context, IRubyObject symbol) {

String id = checkLocalId(context, symbol);

return asBoolean(context, binding.getEvalScope(context.runtime).getStaticScope().isDefinedOrImplicit(id) >= 0);

}

@JRubyMethod

public IRubyObject local_variable_get(ThreadContext context, IRubyObject symbol) {

String id = checkLocalId(context, symbol);

DynamicScope evalScope = binding.getEvalScope(context.runtime);

StaticScope staticScope = evalScope.getStaticScope();

int slot = staticScope.isDefinedOrImplicit(id);

if (slot < 0) throw undefinedVariableError(context, symbol);

return evalScope.getValueOrNil(slot & 0xffff, slot >> 16, context.nil);

}

@JRubyMethod

public IRubyObject local_variable_set(ThreadContext context, IRubyObject symbol, IRubyObject value) {

String id = checkLocalId(context, symbol);

DynamicScope evalScope = binding.getEvalScope(context.runtime);

StaticScope staticScope = evalScope.getStaticScope();

int slot = staticScope.isDefinedOrImplicit(id);

// for the implicit "it" variable

if (slot == StaticScope.IMPLICIT) throw undefinedVariableError(context, symbol);

if (slot == -1) { // Yay! New variable associated with this binding

slot = evalScope.getStaticScope().addVariable(id.intern());

evalScope.growIfNeeded();

}

return evalScope.setValue(slot & 0xffff, value, slot >> 16);

}

@JRubyMethod(name = "implicit_parameter_defined?")

public IRubyObject implicit_parameter_defined_p(ThreadContext context, IRubyObject symbol) {

String id = checkImplicitId(context, symbol);

return asBoolean(context, binding.getDynamicScope().getStaticScope().isDefinedImplicitParameter(id) != -1);

}

@JRubyMethod

public IRubyObject implicit_parameter_get(ThreadContext context, IRubyObject symbol) {

String id = checkImplicitId(context, symbol);

DynamicScope dynamicScope = binding.getDynamicScope();

StaticScope staticScope = dynamicScope.getStaticScope();

int slot = staticScope.isDefinedImplicitParameter(id);

if (slot != StaticScope.IMPLICIT) throw undefinedImplicitVariableError(context, symbol);

slot = staticScope.isDefined(id);

return dynamicScope.getValueOrNil(slot & 0xffff, slot >> 16, context.nil);

}

private static boolean isNumberedVariable(String id) {

return id.length() == 2 && id.charAt(0) == '_' && Character.isDigit(id.charAt(1));

}

private RaiseException numberedParameterError(ThreadContext context, IRubyObject symbol) {

return nameError(context, str(context.runtime, "numbered parameter '", symbol, "' is not a local variable"), symbol);

}

private RaiseException undefinedVariableError(ThreadContext context, IRubyObject symbol) {

return nameError(context, str(context.runtime, "local variable '", symbol, "' not defined for " + inspect(context)), symbol);

}

private RaiseException undefinedImplicitVariableError(ThreadContext context, IRubyObject symbol) {

return nameError(context, str(context.runtime, "'", symbol, "' is not an implicit parameter"), symbol);

}

// MRI: check_local_id

private String checkLocalId(ThreadContext context, IRubyObject obj) {

String id = RubySymbol.idStringFromObject(context, obj);

if (isNumberedVariable(id)) throw numberedParameterError(context, obj);

if (!RubyLexer.isIdentifierChar(id.charAt(0))) {

throw nameError(context, str(context.runtime, "wrong local variable name '", obj, "' for ", this), id);

}

return id;

}

private String checkImplicitId(ThreadContext context, IRubyObject obj) {

String id = RubySymbol.idStringFromObject(context, obj);

if (!isNumberedVariable(id) && !id.equals("it")) throw undefinedImplicitVariableError(context, obj);

return id;

}

@JRubyMethod

public IRubyObject local_variables(ThreadContext context) {

return binding.getEvalScope(context.runtime).getStaticScope().getLocalVariables(context);

}

@JRubyMethod

public IRubyObject implicit_parameters(ThreadContext context) {

return binding.getEvalScope(context.runtime).getStaticScope().getEnclosingScope().getImplicitParameters(context);

}

@JRubyMethod(name = "receiver")

public IRubyObject receiver(ThreadContext context) {

return binding.getSelf();

}

@JRubyMethod

public IRubyObject source_location(ThreadContext context) {

IRubyObject filename = newString(context, binding.getFile()).freeze(context);

RubyFixnum line = asFixnum(context, binding.getLine() + 1); /* zero-based */

return newArray(context, filename, line);

}

}