EqualityInference.java 文件源码

private EqualityInference(Iterable<Set<Expression>> equalityGroups)
{
    ImmutableSetMultimap.Builder<Expression, Expression> setBuilder = ImmutableSetMultimap.builder();
    for (Set<Expression> equalityGroup : equalityGroups) {
        if (!equalityGroup.isEmpty()) {
            setBuilder.putAll(CANONICAL_ORDERING.min(equalityGroup), equalityGroup);
        }
    }
    equalitySets = setBuilder.build();

    ImmutableMap.Builder<Expression, Expression> mapBuilder = ImmutableMap.builder();
    for (Map.Entry<Expression, Expression> entry : equalitySets.entries()) {
        Expression canonical = entry.getKey();
        Expression expression = entry.getValue();
        mapBuilder.put(expression, canonical);
    }
    canonicalMap = mapBuilder.build();
}