/*
|
Copyright (C) 2015 Yusuke Suzuki <utatane.tea@gmail.com>
|
|
Redistribution and use in source and binary forms, with or without
|
modification, are permitted provided that the following conditions are met:
|
|
* Redistributions of source code must retain the above copyright
|
notice, this list of conditions and the following disclaimer.
|
* Redistributions in binary form must reproduce the above copyright
|
notice, this list of conditions and the following disclaimer in the
|
documentation and/or other materials provided with the distribution.
|
|
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
ARE DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
|
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
|
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
*/
|
"use strict";
|
|
const READ = 0x1;
|
const WRITE = 0x2;
|
const RW = READ | WRITE;
|
|
/**
|
* A Reference represents a single occurrence of an identifier in code.
|
* @class Reference
|
*/
|
class Reference {
|
constructor(ident, scope, flag, writeExpr, maybeImplicitGlobal, partial, init) {
|
|
/**
|
* Identifier syntax node.
|
* @member {espreeIdentifier} Reference#identifier
|
*/
|
this.identifier = ident;
|
|
/**
|
* Reference to the enclosing Scope.
|
* @member {Scope} Reference#from
|
*/
|
this.from = scope;
|
|
/**
|
* Whether the reference comes from a dynamic scope (such as 'eval',
|
* 'with', etc.), and may be trapped by dynamic scopes.
|
* @member {boolean} Reference#tainted
|
*/
|
this.tainted = false;
|
|
/**
|
* The variable this reference is resolved with.
|
* @member {Variable} Reference#resolved
|
*/
|
this.resolved = null;
|
|
/**
|
* The read-write mode of the reference. (Value is one of {@link
|
* Reference.READ}, {@link Reference.RW}, {@link Reference.WRITE}).
|
* @member {number} Reference#flag
|
* @private
|
*/
|
this.flag = flag;
|
if (this.isWrite()) {
|
|
/**
|
* If reference is writeable, this is the tree being written to it.
|
* @member {espreeNode} Reference#writeExpr
|
*/
|
this.writeExpr = writeExpr;
|
|
/**
|
* Whether the Reference might refer to a partial value of writeExpr.
|
* @member {boolean} Reference#partial
|
*/
|
this.partial = partial;
|
|
/**
|
* Whether the Reference is to write of initialization.
|
* @member {boolean} Reference#init
|
*/
|
this.init = init;
|
}
|
this.__maybeImplicitGlobal = maybeImplicitGlobal;
|
}
|
|
/**
|
* Whether the reference is static.
|
* @method Reference#isStatic
|
* @returns {boolean} static
|
*/
|
isStatic() {
|
return !this.tainted && this.resolved && this.resolved.scope.isStatic();
|
}
|
|
/**
|
* Whether the reference is writeable.
|
* @method Reference#isWrite
|
* @returns {boolean} write
|
*/
|
isWrite() {
|
return !!(this.flag & Reference.WRITE);
|
}
|
|
/**
|
* Whether the reference is readable.
|
* @method Reference#isRead
|
* @returns {boolean} read
|
*/
|
isRead() {
|
return !!(this.flag & Reference.READ);
|
}
|
|
/**
|
* Whether the reference is read-only.
|
* @method Reference#isReadOnly
|
* @returns {boolean} read only
|
*/
|
isReadOnly() {
|
return this.flag === Reference.READ;
|
}
|
|
/**
|
* Whether the reference is write-only.
|
* @method Reference#isWriteOnly
|
* @returns {boolean} write only
|
*/
|
isWriteOnly() {
|
return this.flag === Reference.WRITE;
|
}
|
|
/**
|
* Whether the reference is read-write.
|
* @method Reference#isReadWrite
|
* @returns {boolean} read write
|
*/
|
isReadWrite() {
|
return this.flag === Reference.RW;
|
}
|
}
|
|
/**
|
* @constant Reference.READ
|
* @private
|
*/
|
Reference.READ = READ;
|
|
/**
|
* @constant Reference.WRITE
|
* @private
|
*/
|
Reference.WRITE = WRITE;
|
|
/**
|
* @constant Reference.RW
|
* @private
|
*/
|
Reference.RW = RW;
|
|
module.exports = Reference;
|
|
/* vim: set sw=4 ts=4 et tw=80 : */
|
