Java Expression类代码示例

import com.facebook.presto.sql.tree.Expression; //导入依赖的package包/类
private OperatorFactory compileFilterWithNoInputColumns(Expression filter, ExpressionCompiler compiler)
{
    filter = ExpressionTreeRewriter.rewriteWith(new SymbolToInputRewriter(ImmutableMap.<Symbol, Integer>of()), filter);

    IdentityHashMap<Expression, Type> expressionTypes = getExpressionTypesFromInput(TEST_SESSION, metadata, SQL_PARSER, INPUT_TYPES, ImmutableList.of(filter));

    try {
        PageProcessor processor = compiler.compilePageProcessor(toRowExpression(filter, expressionTypes), ImmutableList.of());

        return new FilterAndProjectOperator.FilterAndProjectOperatorFactory(0, new PlanNodeId("test"), processor, ImmutableList.<Type>of());
    }
    catch (Throwable e) {
        if (e instanceof UncheckedExecutionException) {
            e = e.getCause();
        }
        throw new RuntimeException("Error compiling " + filter + ": " + e.getMessage(), e);
    }
}
 

import com.facebook.presto.sql.tree.Expression; //导入依赖的package包/类
protected static String processFuncSet(Formatter formatter, FunctionCall node) {
	StringBuilder builder = new StringBuilder();
	String functionName = getFunctionName(node);
	int numArguments = node.getArguments().size();

	builder.append(functionName).append('(').append(formatter.process(node.getArguments().get(0), null)).append(
			')');

	if (numArguments > 1) {
		builder.append(" ON ");
	}

	for (int i = 1; i < numArguments; i++) {
		Expression item = node.getArguments().get(i);

		if (i == 1) {
			builder.append(formatter.process(item, null));
		}
		else {
			builder.append(", ").append(formatter.process(item, null));
		}
	}

	return builder.toString();
}
 

import com.facebook.presto.sql.tree.Expression; //导入依赖的package包/类
@Override
protected String visitArithmeticExpression(ArithmeticExpression node, Void context)
{
    if (node.getType().equals(ArithmeticExpression.Type.DIVIDE)) {
        if (_outputDivideByZeroGuard == true) {
            if (node.getRight() instanceof FunctionCall) {
                if (getFunctionName((FunctionCall) node.getRight()).equals("nullifzero")) {
                    // bypass appending nullifzero
                    return formatBinaryExpression(node.getType().getValue(), node.getLeft(), node.getRight());
                }
            } else if (node.getRight() instanceof Literal) {
    			// purely literal
    			return formatBinaryExpression(node.getType().getValue(), node.getLeft(), node.getRight());
            }
    
            List<Expression> arguments = new ArrayList<Expression>();
            arguments.add(node.getRight());
            FunctionCall nullifzeroFunc = new FunctionCall(new QualifiedName("nullifzero"), arguments);
            return formatBinaryExpression(node.getType().getValue(), node.getLeft(), nullifzeroFunc);
        } else {
            return formatBinaryExpression(node.getType().getValue(), node.getLeft(), node.getRight());
        }
    } else {
        return formatBinaryExpression(node.getType().getValue(), node.getLeft(), node.getRight());
    }
}
 

import com.facebook.presto.sql.tree.Expression; //导入依赖的package包/类
protected String joinPassExpressions(String on, List<Expression> expressions)
{
    return Joiner.on(on).join(transform(expressions, new Function<Expression, Object>()
    {
        @Override
        public Object apply(Expression input)
        {
            if (input instanceof QualifiedNameReference) {
                // 20150709: enclose vero ident in () in case association matters
                return '(' + process(input, null) + ')';
            } else {
                return process(input, null);
            }
        }
    }));
}
 

import com.facebook.presto.sql.tree.Expression; //导入依赖的package包/类
public static void printExpression(String sql)
{
    println(sql.trim());
    println("");

    System.out.println("EXP Printing CommonTree toString...");
    CommonTree tree = VeroSqlParser.parseExpression(sql);
    println(TreePrinter.treeToString(tree));
    println("");

    System.out.println("EXP Printing AST toString...");
    Expression expression = VeroSqlParser.createExpression(tree);
    println(expression.toString());
    println("");

    System.out.println("EXP Printing Format sql toString...");
    // TODO: support formatting all statement types
    println(FormatterFactory.getSqlFormatter().formatSql(expression));
    println("");

    println(repeat("=", 60));
    println("");
}
 

import com.facebook.presto.sql.tree.Expression; //导入依赖的package包/类
@Override
protected Void visitValues(Values node, Integer indent)
{
    builder.append(" VALUES ");

    boolean first = true;
    for (Expression row : node.getRows()) {
        builder.append("\n")
                .append(indentString(indent))
                .append(first ? "  " : ", ");

        builder.append(formatExpression(row, parameters, indent));
        first = false;
    }
    builder.append('\n');

    return null;
}
 

import com.facebook.presto.sql.tree.Expression; //导入依赖的package包/类
/**
 * Parses the list with values to insert and returns them as Objects
 */
@Override
public List<Object> visitValues(Values values, QueryState state){
	List<Object> result = new ArrayList<Object>();
	
	for(Expression rowExpression : values.getRows()){
		if(rowExpression instanceof Row) {
			Row row = (Row)rowExpression;
			for(Expression rowValue : row.getItems()){
				if(!(rowValue instanceof Literal)) {
					state.addException("Unable to parse non-literal value : "+rowValue);
					return result;
				}
				result.add(getObject((Literal)rowValue));
			}
		}else if (rowExpression instanceof Literal){
			result.add(getObject((Literal)rowExpression));
		}else {
			state.addException("Unknown VALUES type "+rowExpression.getClass()+" encountered");
			return null;
		}
	}
	return result;
}
 

import com.facebook.presto.sql.tree.Expression; //导入依赖的package包/类
@Override
public PlanNode visitSample(SampleNode node, RewriteContext<Void> context)
{
    if (node.getSampleType() == SampleNode.Type.BERNOULLI) {
        PlanNode rewrittenSource = context.rewrite(node.getSource());

        ComparisonExpression expression = new ComparisonExpression(
                ComparisonExpression.Type.LESS_THAN,
                new FunctionCall(QualifiedName.of("rand"), ImmutableList.<Expression>of()),
                new DoubleLiteral(Double.toString(node.getSampleRatio())));
        return new FilterNode(node.getId(), rewrittenSource, expression);
    }
    else if (node.getSampleType() == SampleNode.Type.POISSONIZED ||
            node.getSampleType() == SampleNode.Type.SYSTEM) {
        return context.defaultRewrite(node);
    }
    throw new UnsupportedOperationException("not yet implemented");
}
 

import com.facebook.presto.sql.tree.Expression; //导入依赖的package包/类
@Test
public void testFromIsNullPredicate()
        throws Exception
{
    Expression originalExpression = isNull(A);
    ExtractionResult result = fromPredicate(originalExpression);
    assertEquals(result.getRemainingExpression(), TRUE_LITERAL);
    assertEquals(result.getTupleDomain(), withColumnDomains(ImmutableMap.of(A, Domain.onlyNull(BIGINT))));

    originalExpression = isNull(K);
    result = fromPredicate(originalExpression);
    assertEquals(result.getRemainingExpression(), TRUE_LITERAL);
    assertEquals(result.getTupleDomain(), withColumnDomains(ImmutableMap.of(K, Domain.onlyNull(HYPER_LOG_LOG))));

    originalExpression = not(isNull(A));
    result = fromPredicate(originalExpression);
    assertEquals(result.getRemainingExpression(), TRUE_LITERAL);
    assertEquals(result.getTupleDomain(), withColumnDomains(ImmutableMap.of(A, Domain.notNull(BIGINT))));

    originalExpression = not(isNull(K));
    result = fromPredicate(originalExpression);
    assertEquals(result.getRemainingExpression(), TRUE_LITERAL);
    assertEquals(result.getTupleDomain(), withColumnDomains(ImmutableMap.of(K, Domain.notNull(HYPER_LOG_LOG))));
}
 

import com.facebook.presto.sql.tree.Expression; //导入依赖的package包/类
public InterpretedFilterFunction(
        Expression predicate,
        Map<Symbol, Type> symbolTypes,
        Map<Symbol, Integer> symbolToInputMappings,
        Metadata metadata,
        SqlParser sqlParser,
        Session session)
{
    // pre-compute symbol -> input mappings and replace the corresponding nodes in the tree
    Expression rewritten = ExpressionTreeRewriter.rewriteWith(new SymbolToInputRewriter(symbolToInputMappings), predicate);

    // analyze expression so we can know the type of every expression in the tree
    ImmutableMap.Builder<Integer, Type> inputTypes = ImmutableMap.builder();
    for (Map.Entry<Symbol, Integer> entry : symbolToInputMappings.entrySet()) {
        inputTypes.put(entry.getValue(), symbolTypes.get(entry.getKey()));
    }
    IdentityHashMap<Expression, Type> expressionTypes = getExpressionTypesFromInput(session, metadata, sqlParser, inputTypes.build(), rewritten);

    evaluator = ExpressionInterpreter.expressionInterpreter(rewritten, metadata, session, expressionTypes);
}
 

import com.facebook.presto.sql.tree.Expression; //导入依赖的package包/类
@Override
public PlanNode visitTableScan(TableScanNode node, RewriteContext<Void> context)
{
    Expression originalConstraint = null;
    if (node.getOriginalConstraint() != null) {
        originalConstraint = canonicalizeExpression(node.getOriginalConstraint());
    }
    return new TableScanNode(
            node.getId(),
            node.getTable(),
            node.getOutputSymbols(),
            node.getAssignments(),
            node.getLayout(),
            node.getCurrentConstraint(),
            originalConstraint);
}
 

import com.facebook.presto.sql.tree.Expression; //导入依赖的package包/类
@Override
public Void visitProject(ProjectNode node, Void context)
{
    StringBuilder builder = new StringBuilder();
    for (Map.Entry<Symbol, Expression> entry : node.getAssignments().entrySet()) {
        if ((entry.getValue() instanceof QualifiedNameReference) &&
                ((QualifiedNameReference) entry.getValue()).getName().equals(entry.getKey().toQualifiedName())) {
            // skip identity assignments
            continue;
        }
        builder.append(format("%s := %s\\n", entry.getKey(), entry.getValue()));
    }

    printNode(node, "Project", builder.toString(), NODE_COLORS.get(NodeType.PROJECT));
    return node.getSource().accept(this, context);
}
 

import com.facebook.presto.sql.tree.Expression; //导入依赖的package包/类
private Expression rewriteExpression(Expression expression, Predicate<Symbol> symbolScope, boolean allowFullReplacement)
{
    Iterable<Expression> subExpressions = SubExpressionExtractor.extract(expression);
    if (!allowFullReplacement) {
        subExpressions = filter(subExpressions, not(equalTo(expression)));
    }

    ImmutableMap.Builder<Expression, Expression> expressionRemap = ImmutableMap.builder();
    for (Expression subExpression : subExpressions) {
        Expression canonical = getScopedCanonical(subExpression, symbolScope);
        if (canonical != null) {
            expressionRemap.put(subExpression, canonical);
        }
    }

    // Perform a naive single-pass traversal to try to rewrite non-compliant portions of the tree. Prefers to replace
    // larger subtrees over smaller subtrees
    // TODO: this rewrite can probably be made more sophisticated
    Expression rewritten = ExpressionTreeRewriter.rewriteWith(new ExpressionNodeInliner(expressionRemap.build()), expression);
    if (!symbolToExpressionPredicate(symbolScope).apply(rewritten)) {
        // If the rewritten is still not compliant with the symbol scope, just give up
        return null;
    }
    return rewritten;
}
 

import com.facebook.presto.sql.tree.Expression; //导入依赖的package包/类
@Override
protected Type visitInPredicate(InPredicate node, StackableAstVisitorContext<AnalysisContext> context)
{
    Expression value = node.getValue();
    process(value, context);

    Expression valueList = node.getValueList();
    process(valueList, context);

    if (valueList instanceof InListExpression) {
        InListExpression inListExpression = (InListExpression) valueList;

        coerceToSingleType(context,
                "IN value and list items must be the same type: %s",
                ImmutableList.<Expression>builder().add(value).addAll(inListExpression.getValues()).build());
    }
    else if (valueList instanceof SubqueryExpression) {
        coerceToSingleType(context, node, "value and result of subquery must be of the same type for IN expression: %s vs %s", value, valueList);
    }

    expressionTypes.put(node, BOOLEAN);
    return BOOLEAN;
}
 

import com.facebook.presto.sql.tree.Expression; //导入依赖的package包/类
@Override
public Boolean visitWindowFrame(WindowFrame node, Void context)
{
    Optional<Expression> start = node.getStart().getValue();
    if (start.isPresent()) {
        if (!process(start.get(), context)) {
            throw new SemanticException(MUST_BE_AGGREGATE_OR_GROUP_BY, start.get(), "Window frame start must be an aggregate expression or appear in GROUP BY clause");
        }
    }
    if (node.getEnd().isPresent() && node.getEnd().get().getValue().isPresent()) {
        Expression endValue = node.getEnd().get().getValue().get();
        if (!process(endValue, context)) {
            throw new SemanticException(MUST_BE_AGGREGATE_OR_GROUP_BY, endValue, "Window frame end must be an aggregate expression or appear in GROUP BY clause");
        }
    }

    return true;
}