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- /*
- 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 : */
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