value/src/main/java/com/google/auto/value/processor/equalshashcode.vm

## Copyright 2018 Google LLC
##
## 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.

## Shared definitions for @AutoFoo templates. This is included in those templates using
## the #parse directive.
##
## This template uses the Apache Velocity Template Language (VTL).
## The variables ($pkg, $props, and so on) are defined by the fields of AutoValueTemplateVars.
##
## Comments, like this one, begin with ##. The comment text extends up to and including the newline
## character at the end of the line. So comments also serve to join a line to the next one.
## Velocity deletes a newline after a directive (#if, #foreach, #end etc) so ## is not needed there.
## That does mean that we sometimes need an extra blank line after such a directive.
##
## Post-processing will remove unwanted spaces and blank lines, but will not join two lines.
## It will also replace classes spelled as (e.g.) `java.util.Arrays`, with the backquotes, to
## use just Arrays if that class can be imported unambiguously, or java.util.Arrays if not.

## In the following two macros, $p is an object of type AutoValueProcessor.Property
## or AutoOneOfProcessor.Property. $p.kind means the getKind() method of those classes,
## and likewise for $p.getter and $p.nullable (isNullable()).

## Expands to an expression appropriate for comparing the $p property in `this` against
## the $p property in `that`. If we're generating code for `AutoValue_Baz` then
## `that` is of type `Baz`.
## As an example, if $p is the `foo` property and $p.kind is FLOAT,
## this becomes `Float.floatToIntBits(this.foo) == Float.floatToIntBits(that.foo())`
## or `...that.getFoo()...`.
## The expression should be surrounded by parentheses if otherwise there might be precedence
## problems when it is followed by &&.
## A reminder that trailing ## here serves to delete the newline, which we don't want in the output.
#macro (equalsThatExpression $p $subclass)
  #if ($p.kind == "FLOAT")
    Float.floatToIntBits(this.$p) == Float.floatToIntBits(that.${p.getter}()) ##
  #elseif ($p.kind == "DOUBLE")
    Double.doubleToLongBits(this.$p) == Double.doubleToLongBits(that.${p.getter}()) ##
  #elseif ($p.kind.primitive)
    this.$p == that.${p.getter}() ##
  #elseif ($p.kind == "ARRAY")
    `java.util.Arrays`.equals(this.$p, ##
        (that instanceof $subclass) ? (($subclass) that).$p : that.${p.getter}()) ##
  #elseif ($p.nullable)
    (this.$p == null ? that.${p.getter}() == null : this.${p}.equals(that.${p.getter}())) ##
  #else
    this.${p}.equals(that.${p.getter}()) ##
  #end
#end

## Expands to an expression to compute the hashCode of the $p property.
## For example, if $p is the `foo` property and $p.kind is FLOAT,
## this becomes `Float.floatToIntBits(this.foo)`.
## A reminder that trailing ## here serves to delete the newline, which we don't want in the output.
#macro (hashCodeExpression $p)
  #if ($p.kind == "LONG")
    (int) (($p >>> 32) ^ $p) ##
  #elseif ($p.kind == "FLOAT")
    Float.floatToIntBits($p) ##
  #elseif ($p.kind == "DOUBLE")
    (int) ((Double.doubleToLongBits($p) >>> 32) ^ Double.doubleToLongBits($p)) ##
  #elseif ($p.kind == "BOOLEAN")
    $p ? 1231 : 1237 ##
  #elseif ($p.kind.primitive)
    $p ##
  #elseif ($p.kind == "ARRAY")
    `java.util.Arrays`.hashCode($p) ##
  #elseif ($p.nullable)
    ($p == null) ? 0 : ${p}.hashCode() ##
  #else
    ${p}.hashCode() ##
  #end
#end