Examples with RowPattern io.trino.sql.tree.RowPattern used on opensource projects

Example 1 with RowPattern

use of io.trino.sql.tree.RowPattern in project trino by trinodb.

the class PatternRecognitionAnalyzer method analyze.

public static PatternRecognitionAnalysis analyze(List<SubsetDefinition> subsets, List<VariableDefinition> variableDefinitions, List<MeasureDefinition> measures, RowPattern pattern, Optional<SkipTo> skipTo) {
    // extract label names (Identifiers) from PATTERN and SUBSET clauses. create labels respecting SQL identifier semantics
    Set<String> primaryLabels = extractExpressions(ImmutableList.of(pattern), Identifier.class).stream().map(PatternRecognitionAnalyzer::label).collect(toImmutableSet());
    List<String> unionLabels = subsets.stream().map(SubsetDefinition::getName).map(PatternRecognitionAnalyzer::label).collect(toImmutableList());
    // analyze SUBSET
    Set<String> unique = new HashSet<>();
    for (SubsetDefinition subset : subsets) {
        String label = label(subset.getName());
        if (primaryLabels.contains(label)) {
            throw semanticException(INVALID_LABEL, subset.getName(), "union pattern variable name: %s is a duplicate of primary pattern variable name", subset.getName());
        }
        if (!unique.add(label)) {
            throw semanticException(INVALID_LABEL, subset.getName(), "union pattern variable name: %s is declared twice", subset.getName());
        }
        for (Identifier element : subset.getIdentifiers()) {
            // TODO can there be repetitions in the list of subset elements? (currently repetitions are supported)
            if (!primaryLabels.contains(label(element))) {
                throw semanticException(INVALID_LABEL, element, "subset element: %s is not a primary pattern variable", element);
            }
        }
    }
    // analyze DEFINE
    unique = new HashSet<>();
    for (VariableDefinition definition : variableDefinitions) {
        String label = label(definition.getName());
        if (!primaryLabels.contains(label)) {
            throw semanticException(INVALID_LABEL, definition.getName(), "defined variable: %s is not a primary pattern variable", definition.getName());
        }
        if (!unique.add(label)) {
            throw semanticException(INVALID_LABEL, definition.getName(), "pattern variable with name: %s is defined twice", definition.getName());
        }
        // DEFINE clause only supports RUNNING semantics which is default
        Expression expression = definition.getExpression();
        extractExpressions(ImmutableList.of(expression), FunctionCall.class).stream().filter(functionCall -> functionCall.getProcessingMode().map(mode -> mode.getMode() == FINAL).orElse(false)).findFirst().ifPresent(functionCall -> {
            throw semanticException(INVALID_PROCESSING_MODE, functionCall.getProcessingMode().get(), "FINAL semantics is not supported in DEFINE clause");
        });
    }
    // record primary labels without definitions. they are implicitly associated with `true` condition
    Set<String> undefinedLabels = Sets.difference(primaryLabels, unique);
    // validate pattern quantifiers
    ImmutableMap.Builder<NodeRef<RangeQuantifier>, Range> ranges = ImmutableMap.builder();
    preOrder(pattern).filter(RangeQuantifier.class::isInstance).map(RangeQuantifier.class::cast).forEach(quantifier -> {
        Optional<Long> atLeast = quantifier.getAtLeast().map(LongLiteral::getValue);
        atLeast.ifPresent(value -> {
            if (value < 0) {
                throw semanticException(NUMERIC_VALUE_OUT_OF_RANGE, quantifier, "Pattern quantifier lower bound must be greater than or equal to 0");
            }
            if (value > Integer.MAX_VALUE) {
                throw semanticException(NUMERIC_VALUE_OUT_OF_RANGE, quantifier, "Pattern quantifier lower bound must not exceed " + Integer.MAX_VALUE);
            }
        });
        Optional<Long> atMost = quantifier.getAtMost().map(LongLiteral::getValue);
        atMost.ifPresent(value -> {
            if (value < 1) {
                throw semanticException(NUMERIC_VALUE_OUT_OF_RANGE, quantifier, "Pattern quantifier upper bound must be greater than or equal to 1");
            }
            if (value > Integer.MAX_VALUE) {
                throw semanticException(NUMERIC_VALUE_OUT_OF_RANGE, quantifier, "Pattern quantifier upper bound must not exceed " + Integer.MAX_VALUE);
            }
        });
        if (atLeast.isPresent() && atMost.isPresent()) {
            if (atLeast.get() > atMost.get()) {
                throw semanticException(INVALID_RANGE, quantifier, "Pattern quantifier lower bound must not exceed upper bound");
            }
        }
        ranges.put(NodeRef.of(quantifier), new Range(atLeast.map(Math::toIntExact), atMost.map(Math::toIntExact)));
    });
    // validate AFTER MATCH SKIP
    Set<String> allLabels = ImmutableSet.<String>builder().addAll(primaryLabels).addAll(unionLabels).build();
    skipTo.flatMap(SkipTo::getIdentifier).ifPresent(identifier -> {
        String label = label(identifier);
        if (!allLabels.contains(label)) {
            throw semanticException(INVALID_LABEL, identifier, "%s is not a primary or union pattern variable", identifier);
        }
    });
    // check no prohibited nesting: cannot nest one row pattern recognition within another
    List<Expression> expressions = Streams.concat(measures.stream().map(MeasureDefinition::getExpression), variableDefinitions.stream().map(VariableDefinition::getExpression)).collect(toImmutableList());
    expressions.forEach(expression -> preOrder(expression).filter(child -> child instanceof PatternRecognitionRelation || child instanceof RowPattern).findFirst().ifPresent(nested -> {
        throw semanticException(NESTED_ROW_PATTERN_RECOGNITION, nested, "nested row pattern recognition in row pattern recognition");
    }));
    return new PatternRecognitionAnalysis(allLabels, undefinedLabels, ranges.buildOrThrow());
}