Parser Configuration

/**
 * Configuration class for controlling parser behavior
 */
public class ParserConfiguration {
    
    /**
     * Create configuration with default settings
     */
    public ParserConfiguration();
    
    /**
     * Set Java language level to support
     * @param languageLevel Target Java version
     * @return This configuration for chaining
     */
    public ParserConfiguration setLanguageLevel(LanguageLevel languageLevel);
    
    /**
     * Get current language level
     * @return Current language level setting
     */
    public LanguageLevel getLanguageLevel();
    
    /**
     * Set character encoding for source files
     * @param characterEncoding Character encoding (e.g., UTF-8)
     * @return This configuration for chaining
     */
    public ParserConfiguration setCharacterEncoding(Charset characterEncoding);
    
    /**
     * Get current character encoding
     * @return Current character encoding
     */
    public Charset getCharacterEncoding();
    
    /**
     * Enable/disable token storage for position tracking
     * @param storeTokens true to store tokens
     * @return This configuration for chaining
     */
    public ParserConfiguration setStoreTokens(boolean storeTokens);
    
    /**
     * Check if token storage is enabled
     * @return true if tokens are stored
     */
    public boolean isStoreTokens();
    
    /**
     * Set tab width for position calculations
     * @param tabWidth Number of spaces per tab
     * @return This configuration for chaining
     */
    public ParserConfiguration setTabWidth(int tabWidth);
    
    /**
     * Get tab width setting
     * @return Current tab width
     */
    public int getTabWidth();
}

/**
 * Java language level enumeration
 */
public enum LanguageLevel {
    /** Java 1.0 support */
    JAVA_1_0,
    /** Java 1.1 support */
    JAVA_1_1, 
    /** Java 1.2 support */
    JAVA_1_2,
    /** Java 1.3 support */
    JAVA_1_3,
    /** Java 1.4 support */
    JAVA_1_4,
    /** Java 5 support (generics, annotations, autoboxing) */
    JAVA_5,
    /** Java 6 support */
    JAVA_6,
    /** Java 7 support (diamond operator, try-with-resources) */
    JAVA_7,
    /** Java 8 support (lambdas, method references, streams) */
    JAVA_8,
    /** Java 9 support (modules, private interface methods) */
    JAVA_9,
    /** Java 10 support (var keyword) */
    JAVA_10,
    /** Java 11 support (var in lambda parameters) */
    JAVA_11,
    /** Java 12 support (switch expressions preview) */
    JAVA_12,
    /** Java 13 support (text blocks preview) */
    JAVA_13,
    /** Java 14 support (switch expressions, records preview) */
    JAVA_14,
    /** Java 15 support (text blocks, sealed classes preview) */
    JAVA_15,
    /** Java 16 support (records, pattern matching instanceof) */
    JAVA_16,
    /** Java 17 support (sealed classes, switch pattern matching) */
    JAVA_17,
    /** Java 18 support */
    JAVA_18,
    /** Java 19 support */
    JAVA_19,
    /** Java 20 support */
    JAVA_20,
    /** Java 21 support (virtual threads, pattern matching) */
    JAVA_21,
    /** Current/latest supported version */
    CURRENT
}

import com.github.javaparser.ParserConfiguration;
import com.github.javaparser.ParserConfiguration.LanguageLevel;
import java.nio.charset.StandardCharsets;

// Configure for Java 17 with UTF-8 encoding
ParserConfiguration config = new ParserConfiguration()
    .setLanguageLevel(LanguageLevel.JAVA_17)
    .setCharacterEncoding(StandardCharsets.UTF_8)
    .setStoreTokens(true)  // Enable position tracking
    .setTabWidth(4);       // 4 spaces per tab

// Use configuration with parser
JavaParser parser = new JavaParser(config);

// Parse with specific language level
ParseResult<CompilationUnit> result = parser.parse(modernJavaCode);

// Different configurations for different purposes
ParserConfiguration legacyConfig = new ParserConfiguration()
    .setLanguageLevel(LanguageLevel.JAVA_8);  // For older codebases

ParserConfiguration modernConfig = new ParserConfiguration()
    .setLanguageLevel(LanguageLevel.JAVA_21)  // Latest features
    .setStoreTokens(true);                    // For IDE-like features

/**
 * Set symbol resolver for type analysis
 * @param symbolResolver Symbol resolver implementation
 * @return This configuration for chaining
 */
public ParserConfiguration setSymbolResolver(SymbolResolver symbolResolver);

/**
 * Get current symbol resolver
 * @return Current symbol resolver or null if not set
 */
public Optional<SymbolResolver> getSymbolResolver();

/**
 * Check if symbol resolution is enabled
 * @return true if symbol resolver is configured
 */
public boolean isSymbolResolutionEnabled();

import com.github.javaparser.symbolsolver.JavaSymbolSolver;
import com.github.javaparser.symbolsolver.resolution.typesolvers.CombinedTypeSolver;
import com.github.javaparser.symbolsolver.resolution.typesolvers.ReflectionTypeSolver;
import com.github.javaparser.symbolsolver.resolution.typesolvers.JavaParserTypeSolver;

// Set up symbol resolution
CombinedTypeSolver typeSolver = new CombinedTypeSolver();
typeSolver.add(new ReflectionTypeSolver());  // JDK classes
typeSolver.add(new JavaParserTypeSolver(new File("src/main/java")));  // Project sources

JavaSymbolSolver symbolResolver = new JavaSymbolSolver(typeSolver);

// Configure parser with symbol resolution
ParserConfiguration config = new ParserConfiguration()
    .setLanguageLevel(LanguageLevel.JAVA_17)
    .setSymbolResolver(symbolResolver);

JavaParser parser = new JavaParser(config);

// Now parsing enables type resolution
CompilationUnit cu = parser.parse(code).getResult().get();

// Resolve types and symbols
for (NameExpr nameExpr : cu.findAll(NameExpr.class)) {
    try {
        ResolvedValueDeclaration resolved = nameExpr.resolve();
        System.out.println("Symbol: " + resolved.getName() + " -> " + resolved.getType());
    } catch (UnsolvedSymbolException e) {
        System.out.println("Could not resolve: " + nameExpr.getNameAsString());
    }
}

/**
 * Set validators for additional syntax and semantic checks
 * @param validators List of validators to apply
 * @return This configuration for chaining
 */
public ParserConfiguration setValidators(List<Validator> validators);

/**
 * Get current validators
 * @return List of configured validators
 */
public List<Validator> getValidators();

/**
 * Add a validator to the configuration
 * @param validator Validator to add
 * @return This configuration for chaining
 */
public ParserConfiguration addValidator(Validator validator);

/**
 * Set problem reporter for handling parse problems
 * @param problemReporter Problem reporter implementation
 * @return This configuration for chaining
 */
public ParserConfiguration setProblemReporter(ProblemReporter problemReporter);

/**
 * Get current problem reporter
 * @return Current problem reporter
 */
public ProblemReporter getProblemReporter();

import com.github.javaparser.ast.validator.*;

// Configure validation for specific Java version
ParserConfiguration config = new ParserConfiguration()
    .setLanguageLevel(LanguageLevel.JAVA_8);

// Add custom validators
config.addValidator(new ReservedKeywordValidator())
      .addValidator(new Java8Validator());

// Custom problem reporter
config.setProblemReporter(new ProblemReporter() {
    @Override
    public void report(Problem problem) {
        System.err.println("Parse issue: " + problem.getMessage());
        if (problem.getLocation().isPresent()) {
            TokenRange location = problem.getLocation().get();
            System.err.println("At: " + location.getBegin());
        }
    }
});

JavaParser parser = new JavaParser(config);

/**
 * Set preprocessing providers for source transformation
 * @param providers Preprocessing providers
 * @return This configuration for chaining
 */
public ParserConfiguration setPreprocessors(List<Processor> providers);

/**
 * Add preprocessing provider
 * @param processor Processor to add
 * @return This configuration for chaining
 */
public ParserConfiguration addProcessor(Processor processor);

/**
 * Set line ending processing provider
 * @param provider Line ending processor
 * @return This configuration for chaining
 */
public ParserConfiguration setLineEndingProcessingProvider(LineEndingProcessingProvider provider);

/**
 * Set unicode escape processing provider
 * @param provider Unicode escape processor
 * @return This configuration for chaining
 */
public ParserConfiguration setUnicodeEscapeProcessingProvider(UnicodeEscapeProcessingProvider provider);

// Configure line ending normalization
config.setLineEndingProcessingProvider(
    LineEndingProcessingProvider.NORMALIZE_TO_LF);

// Configure unicode escape processing
config.setUnicodeEscapeProcessingProvider(
    UnicodeEscapeProcessingProvider.PROCESS_ESCAPES);

// Add custom preprocessor
config.addProcessor(new Processor() {
    @Override
    public String process(String code) {
        // Custom preprocessing logic
        return code.replace("//FIXME", "//TODO");
    }
});

/**
 * Set whether to store original tokens for position tracking
 * @param storeTokens true to store tokens (uses more memory)
 * @return This configuration for chaining
 */
public ParserConfiguration setStoreTokens(boolean storeTokens);

/**
 * Set whether to perform expensive validation checks
 * @param performExpensiveChecks true to enable extensive validation
 * @return This configuration for chaining
 */
public ParserConfiguration setPerformExpensiveChecks(boolean performExpensiveChecks);

/**
 * Set whether to cache parsing results
 * @param cacheParsingResults true to enable caching
 * @return This configuration for chaining
 */
public ParserConfiguration setCacheParsingResults(boolean cacheParsingResults);

/**
 * Set maximum parsing depth to prevent stack overflow
 * @param maxParsingDepth Maximum recursion depth
 * @return This configuration for chaining
 */
public ParserConfiguration setMaxParsingDepth(int maxParsingDepth);

// Performance-optimized configuration
ParserConfiguration fastConfig = new ParserConfiguration()
    .setStoreTokens(false)           // Save memory
    .setPerformExpensiveChecks(false) // Skip expensive validation
    .setCacheParsingResults(true)     // Enable caching
    .setMaxParsingDepth(1000);        // Prevent deep recursion

// Memory-optimized configuration
ParserConfiguration memoryConfig = new ParserConfiguration()
    .setStoreTokens(false)           // Don't store tokens
    .setCacheParsingResults(false);   // Don't cache results

// Full-featured configuration (more memory usage)
ParserConfiguration fullConfig = new ParserConfiguration()
    .setStoreTokens(true)            // Store for position tracking
    .setPerformExpensiveChecks(true) // Full validation
    .setSymbolResolver(symbolResolver); // Enable type resolution

/**
 * Utility methods for common configuration patterns
 */
public class ParserConfigurationPresets {
    
    /**
     * Configuration optimized for IDE features
     * @return Configuration with full position tracking and symbol resolution
     */
    public static ParserConfiguration ideConfiguration() {
        return new ParserConfiguration()
            .setLanguageLevel(LanguageLevel.CURRENT)
            .setStoreTokens(true)
            .setPerformExpensiveChecks(true);
    }
    
    /**
     * Configuration optimized for batch processing
     * @return Lightweight configuration for processing many files
     */
    public static ParserConfiguration batchProcessingConfiguration() {
        return new ParserConfiguration()
            .setStoreTokens(false)
            .setPerformExpensiveChecks(false)
            .setCacheParsingResults(true);
    }
    
    /**
     * Configuration for legacy Java code
     * @return Configuration for older Java versions
     */
    public static ParserConfiguration legacyConfiguration() {
        return new ParserConfiguration()
            .setLanguageLevel(LanguageLevel.JAVA_8);
    }
    
    /**
     * Configuration for modern Java features
     * @return Configuration supporting latest Java features
     */
    public static ParserConfiguration modernConfiguration() {
        return new ParserConfiguration()
            .setLanguageLevel(LanguageLevel.JAVA_21);
    }
}

// Use preset configurations
JavaParser ideParser = new JavaParser(ParserConfigurationPresets.ideConfiguration());
JavaParser batchParser = new JavaParser(ParserConfigurationPresets.batchProcessingConfiguration());
JavaParser legacyParser = new JavaParser(ParserConfigurationPresets.legacyConfiguration());

// Customize preset
ParserConfiguration customConfig = ParserConfigurationPresets.modernConfiguration()
    .setCharacterEncoding(StandardCharsets.UTF_8)
    .setSymbolResolver(mySymbolResolver);

/**
 * Fluent configuration builder
 */
public class ParserConfigurationBuilder {
    
    /**
     * Start building configuration
     * @return New builder instance
     */
    public static ParserConfigurationBuilder builder() {
        return new ParserConfigurationBuilder();
    }
    
    /**
     * Set language level
     * @param level Java language level
     * @return This builder for chaining
     */
    public ParserConfigurationBuilder languageLevel(LanguageLevel level) {
        // Implementation
        return this;
    }
    
    /**
     * Enable symbol resolution with type solver
     * @param typeSolver Type solver to use
     * @return This builder for chaining
     */
    public ParserConfigurationBuilder symbolResolution(TypeSolver typeSolver) {
        // Implementation
        return this;
    }
    
    /**
     * Build final configuration
     * @return Configured ParserConfiguration
     */
    public ParserConfiguration build() {
        // Implementation
        return new ParserConfiguration();
    }
}

// Complex configuration with builder
ParserConfiguration config = ParserConfigurationBuilder.builder()
    .languageLevel(LanguageLevel.JAVA_17)
    .symbolResolution(typeSolver)
    .encoding(StandardCharsets.UTF_8)
    .storeTokens(true)
    .validators(Arrays.asList(
        new ReservedKeywordValidator(),
        new Java17Validator()
    ))
    .problemReporter(customReporter)
    .build();

JavaParser parser = new JavaParser(config);

/**
 * Validate configuration settings
 * @param config Configuration to validate
 * @throws IllegalArgumentException if configuration is invalid
 */
public static void validateConfiguration(ParserConfiguration config);

/**
 * Get configuration warnings
 * @param config Configuration to check
 * @return List of configuration warnings
 */
public static List<String> getConfigurationWarnings(ParserConfiguration config);