com.squarespace.less.model.Parameter Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of less-compiler Show documentation
Squarespace LESS compiler
The newest version!
/**
 * Copyright (c) 2014 SQUARESPACE, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.squarespace.less.model;

import static com.squarespace.less.core.LessUtils.safeEquals;

import com.squarespace.less.LessException;
import com.squarespace.less.core.Buffer;
import com.squarespace.less.exec.ExecEnv;


/**
 * Parameter of a {@link Mixin} definition.
 */
public class Parameter implements Node, HasUserData {

  /**
   * Parameter name.
   */
  protected final String name;

  /**
   * Parameter's value.
   */
  protected final Node value;

  /**
   * Indicates whether this parameter is variadic.
   */
  protected final boolean variadic;

  /**
   * User data associated with this node.
   */
  protected Object userData = null;

  /**
   * Constructs a parameter with the given name.
   */
  public Parameter(String name) {
    this(name, null);
  }

  /**
   * Constructs a parameter with the given name and value.
   */
  public Parameter(String name, Node value) {
    this.name = name;
    this.value = value;
    this.variadic = false;
  }

  /**
   * Constructs a variadic parameter with the given name.
   */
  public Parameter(String name, boolean variadic) {
    this.name = name;
    this.value = null;
    this.variadic = variadic;
  }

  /**
   * Returns the parameter's name.
   */
  public String name() {
    return name;
  }

  /**
   * Returns the parameter's value.
   */
  public Node value() {
    return value;
  }

  /**
   * Indicates whether this parameter is variadic.
   */
  public boolean variadic() {
    return variadic;
  }

  @Override
  public boolean hasUserData() {
    return true;
  }

  @Override
  public Object userData() {
    return userData;
  }

  @Override
  public void userData(Object userData) {
    this.userData = userData;
  }

  /**
   * See {@link Node#needsEval()}
   */
  @Override
  public boolean needsEval() {
    return value != null ? value.needsEval() : false;
  }

  /**
   * See {@link Node#eval(ExecEnv)}
   */
  @Override
  public Node eval(ExecEnv env) throws LessException {
    if (!needsEval()) {
      return this;
    }
    return value == null ? new Parameter(name, variadic) : new Parameter(name, value.eval(env));
  }

  /**
   * See {@link Node#type()}
   */
  @Override
  public NodeType type() {
    return NodeType.PARAMETER;
  }

  /**
   * See {@link Node#repr(Buffer)}
   */
  @Override
  public void repr(Buffer buf) {
    if (name != null) {
      buf.append(name);
      if (value != null) {
        buf.append(": ");
        value.repr(buf);
      } else if (variadic) {
        buf.append(" ...");
      }
    } else if (value != null) {
      value.repr(buf);
    } else if (variadic) {
      buf.append("...");
    }
  }

  /**
   * See {@link Node#modelRepr(Buffer)}
   */
  @Override
  public void modelRepr(Buffer buf) {
    typeRepr(buf);
    posRepr(buf);
    buf.append(' ').append(name);
    if (variadic) {
      buf.append(" [variadic]");
    }
    if (value != null) {
      buf.incrIndent().append('\n').indent();
      value.modelRepr(buf);
      buf.decrIndent();
    }
  }

  @Override
  public boolean equals(Object obj) {
    if (obj instanceof Parameter) {
      Parameter other = (Parameter)obj;
      return variadic == other.variadic
          && safeEquals(name, other.name)
          && safeEquals(value, other.value);
    }
    return false;
  }

  @Override
  public String toString() {
    return ModelUtils.toString(this);
  }

  @Override
  public int hashCode() {
    return ModelUtils.notHashable();
  }

}