Practical, working examples of DWScript in action, organized by category.
Practical demonstration of using class-level attributes and RTTI for metadata-driven object validation. This example shows how to define constraints at the class level and build a validation engine that enforces them.
Demonstrates DWScript's advanced syntax for defining domain-specific languages (DSL) via operator overloading. This example showcases the 'class operator' syntax to implement custom membership logic ('in') for complex types like date ranges and fluent increment operators ('+=') for building building builders, illustrating how to create highly readable and expressive APIs.
Showcases formal verification and defensive programming using built-in contract keywords. This example illustrates the 'require' (pre-conditions) and 'ensure' (post-conditions) syntax to define strict API boundaries, showcasing how to validate input parameters and output results at runtime to catch logic errors early and improve software reliability.
Deep dive into Pascal's powerful type-safe constants and bitmask management. This example demonstrates defining enumerations, using the 'set of' construct for efficient collection management, and performing set-theoretic operations (union, intersection, difference) while showcasing the native ability to cast sets to integers for low-level bitmask manipulation.
Showcases the power of interface-driven design for creating decoupled and extensible architectures. This example demonstrates defining interfaces, implementing multiple behaviors across disparate class hierarchies, and using the 'implements' operator for safe runtime discovery and casting of interface implementations.
Illustrates modern functional programming paradigms using anonymous subroutines and lexical closures. This example showcases the concise 'lambda' arrow syntax, capturing local state in closures, and utilizing higher-order methods like 'Filter', 'Map', and 'Sort' to perform declarative transformations on dynamic collections.
Demonstrates the sophisticated use of class references ('class of') for implementing runtime dynamic behaviors. This example showcases the Factory pattern by treating classes as first-class values, allowing for the instantiation of specific subclasses based on metadata or runtime logic, and illustrating virtual constructor patterns.
A comprehensive introduction to class-based design and polymorphism. This example explores defining class hierarchies, using 'virtual' and 'abstract' methods to define extensible interfaces, overriding constructors, and managing heterogeneous object collections using dynamic arrays of base class references.
Explores advanced record features that differentiate DWScript from traditional Pascal. This example highlights default field values, anonymous record syntax for quick data structures, and the built-in JSON serialization capabilities for complex record hierarchies.
Showcases declarative programming and metadata-driven logic. This example demonstrates how to define custom attribute classes inheriting from 'TCustomAttribute', annotate other types with these attributes, and use 'RTTIRawAttributes' to programmatically discover and act upon this metadata at runtime for tasks like mapping classes to database tables.
Illustrates the extensive runtime introspection capabilities of DWScript. This example showcases the use of 'TypeOf' and 'RTTIRawAttributes' to explore class members (fields, properties, methods) at runtime, demonstrating how to dynamically inspect types and perform property access by name without compile-time knowledge.
Demonstrates DWScript's built-in string pattern matching capabilities. This example showcases the 'StrMatches' function, which allows for simple yet powerful wildcard-based matching (using '*' and '?') without the complexity of full regular expressions.
Demonstrates string building and array-based lookup tables. This example showcases the 'weights' and 'symbols' constant arrays, 'High' property for array bounds, and efficient string concatenation using the '+=' operator.
Comprehensive overview of DWScript's modern, fluent string manipulation API. This example showcases method-style transformations including 'Trim', 'Split', and 'Replace', illustrating substring extraction with 'Copy', specialized deletions via 'DeleteLeft' and 'DeleteRight', and the versatile 'Format' function for building complex templated output.
Illustrates character-level string manipulation and modular arithmetic. This example demonstrates using 'Ord' and 'Chr' for character conversions, set membership checking for alphabetic filters, and 1-based string indexing in DWScript.
Demonstrates sophisticated management of dynamic arrays containing records. This example showcases custom sorting logic using lambda comparators, array removal operations, and extracting subsets using slicing techniques for task management scenarios.
Showcases modern functional programming methods on dynamic arrays. This example demonstrates using 'Filter' with lambdas, 'Map' with anonymous functions, and 'Foreach' for concise collection processing and transformations.
Demonstrates the creation and management of nested dynamic arrays (jagged arrays). This example illustrates initializing a matrix, nested 'SetLength' calls, and iterating through high-dimensional data structures.
Explores subset extraction and array management using the 'Copy' method. This example highlights how to efficiently slice dynamic arrays into smaller segments by specifying starting indices and counts.
Demonstrates built-in sorting and transformation methods for dynamic arrays. It showcases the 'Sort' method for both integers and strings, the 'Reverse' method, and integration with JSON serialization for debugging.
Illustrates implementing common data structures using dynamic arrays. This example demonstrates LIFO (Stack) patterns using 'High' and 'Delete', and FIFO (Queue) patterns by adding elements and deleting from index 0.
Demonstrates numerical processing and JSON integration. This example shows how to perform aggregate calculations (sum, mean, variance) on numerical arrays and bundle the results into a 'JSONVariant' object for structured reporting.
Introduces associative arrays (dictionaries) in DWScript. It demonstrates the 'array [String] of T' syntax, basic key-value pair insertion, value retrieval, existence checking, and entry removal, highlighting the performance and convenience of indexed lookups.
Showcases the flexibility of associative arrays in DWScript. This example demonstrates using 'Integer' and 'Float' types as keys in addition to strings, highlighting the language's support for non-string indexing in dictionaries.
Demonstrates storing structured data in associative arrays. This example illustrates mapping string keys to record types, enabling the creation of efficient, type-safe directories and the manipulation of complex values stored within dictionaries.
Demonstrates a classic use case for associative arrays. This example showcases word frequency analysis by combining string splitting with automatic initialization of dictionary values, followed by iteration over the 'Keys' collection.
Showcases advanced nesting of collection types. This example demonstrates how to group records into categories using an associative array where each value is itself a dynamic array, illustrating DWScript's support for complex, nested data structures.
Explores the methods for traversing associative arrays. It demonstrates using the '.Keys' property to access dictionary identifiers and performing key-based lookups during iteration to retrieve associated values.
Illustrates foundational array manipulation techniques. This example demonstrates using the 'for-in' loop to iterate over elements and the 'Add' method to dynamically build a new collection based on a condition, serving as a base comparison for built-in functional methods.
Demonstrates high-precision integer math beyond standard 64-bit limits. This example showcases the native 'BigInteger' type, illustrating its use in calculating massive factorials, performing modular exponentiation ('ModPow') for cryptographic applications, and utilizing helper functions like 'GCD' and bit-level inspection.
Explores advanced mathematical concepts using arbitrary-precision integers. This example showcases factorials of large numbers, efficient primality testing using the 'IsPrime' method, and the 'ModPow' function for secure numerical transformations, highlighting the efficiency of native BigInt operators.
Demonstrates numerical processing and signal analysis concepts. This example showcases array pre-allocation with 'SetLength', floating-point arithmetic, and the use of the standard math library for complex numerical calculations.
Demonstrates algorithmic optimization and recursive logic in DWScript. This example showcases the implementation of the Fibonacci sequence using both a naive iterative approach and a recursive pattern enhanced with memoization using associative arrays, illustrating how to trade memory for computational speed.
Demonstrates high-precision floating-point arithmetic and built-in trigonometry functions. This example showcases calculating great-circle distances using 'Haversine', highlighting the standard library's support for geospatial mathematics.
Demonstrates linear algebra operations and 1D array indexing for performance. This example showcases using records to encapsulate data structures, manual array resizing with 'SetLength', and efficient nested loop patterns for mathematical transformations.
Illustrates numerical methods and floating-point precision. This example demonstrates the Secant method for finding polynomial roots, showcasing the use of the 'Abs' function for convergence checks and high-precision 'Float' arithmetic.
Mixing & Mastering
Efficiently finds all prime numbers up to a given limit. This example demonstrates basic loop structures, dynamic Boolean arrays, and optimized arithmetic for a classic algorithmic problem.
Illustrates basic arithmetic and control flow for prime factorization. This example demonstrates nested 'while' loops, the 'mod' operator for divisibility checks, and string building via the '+=' operator to format mathematical results.
Classic recursive puzzle solution. This example demonstrates recursive function calls and string concatenation in DWScript to solve the Towers of Hanoi problem.
Showcases multidimensional arrays and string metric calculations. This example demonstrates the allocation of a 2D integer array ('new Integer[slen + 1, tlen + 1]') and the use of 'MinInt' for dynamic programming calculations.
Demonstrates recursive backtracking and complex array manipulation. This example showcases using an array of records as a manual stack, the 'RandomInt' function for stochastic pathfinding, and custom 'step' increments in 'for' loops for grid rendering.
Implementation of Bubble Sort and Quick Sort. This example demonstrates procedural programming patterns, recursive subroutines, and the performance differences between O(n^2) and O(n log n) algorithms in DWScript.
Deep dive into low-level binary manipulation and memory-efficient data structures. This example showcases the 'ByteBuffer' type for granular byte-level access, illustrating how to set and get multi-byte primitives (Int32, Double, Word) with explicit endianness control, perform hex-encoded diagnostic dumps, and utilize the 'DataString' pattern for seamless binary I/O and type casting between raw memory and managed types.
Demonstrates first-class JSON support and the seamless integration between Pascal types and dynamic objects. This example showcases the 'JSON' unit's 'NewObject' and 'NewArray' constructors for programmatic building, the 'Stringify' method for serialization, and 'Parse' for transforming external data into navigable objects with native dot-notation property access.
Neural Network Inference & Optimization: Using 'TabularData' to find optimal weights for a Titanic survival model. This example demonstrates an automated grid search that evaluates hundreds of model variations in milliseconds to discover non-linear interactions that outperform the standard gender-only baseline.
Illustrates the 'System.Data' abstraction layer for robust database interactions. This example demonstrates using the 'DataBase' factory for connection management (in-memory and file-based), executing schema-modifying SQL, implementing secure parameterized queries to prevent SQL injection, and leveraging high-performance result set navigation with the 'TDataSet.Step' pattern.
Showcases high-throughput data ingestion patterns by bridging managed collections and the database engine. This example highlights serializing an 'array of record' to a single JSON payload and utilizing SQLite's 'json_each' and 'json_extract' functions to perform set-based inserts, significantly reducing round-trip overhead compared to individual 'INSERT' statements.
In-depth exploration of the 'TDataSet' interface for data consumption and manipulation. This example illustrates advanced field access techniques (named vs. indexed access), type-safe retrieval (AsInteger, AsString), and the 'IsNull' predicate, showcasing the efficiency of forward-only cursors for handling large-scale database results.
Demonstrates the native bridge between relational data and JSON serialization. This example showcases the 'StringifyAll' method for converting entire result sets into structured JSON arrays and the 'Stringify' method for single-record objects, enabling rapid API development and data exchange.
Illustrates the principles of ACID compliance and data integrity in multi-step database operations. This example demonstrates managing atomic blocks with 'BeginTransaction', 'Commit', and 'Rollback', showcasing robust error handling within 'try..except' constructs to prevent data corruption during partial failures.
High-performance data transformation and analysis. This example demonstrates using 'TabularData' for data science tasks like feature normalization, linear modeling with ReLU activation, and error metrics (SMAPE), highlighting the efficiency of JIT-compiled RPN expressions for bulk processing.
Demonstrates standard-compliant HTTP caching strategies to optimize web performance. This example showcases using 'HashSHA256' to generate content fingerprints, illustrating how to inspect 'WebRequest.Header' for conditional validation and use 'WebResponse.SetETag' to implement efficient 304 Not Modified status handling.
In-depth demonstration of managing HTTP state and client metadata. This example illustrates using the 'WebRequest' object to traverse incoming HTTP headers and 'WebResponse.SetCookie' to manage persistent client-side data, highlighting the use of security-critical flags like HttpOnly and SameSite for robust web application security.
Showcases high-concurrency state management and request throttling using thread-safe global storage. This example demonstrates the 'IncrementGlobalVar' atomic operation, illustrating how to implement sophisticated IP-based rate limiting with automatic temporal expiration (TTL), essential for protecting public API endpoints from denial-of-service and brute-force attacks in a distributed web environment.
Illustrates robust URL routing and input validation patterns for web security. This example demonstrates using 'WebResponse.SetStatusRedirect' for HTTP 302 responses, showcasing a defensive whitelist validation logic to mitigate Open Redirect vulnerabilities and ensure users remain within trusted domain boundaries.
Showcases the versatile 'WebResponse' API for controlling server output and status codes. This example demonstrates high-level shortcuts like 'SetContentJSON' for automated data serialization, 'SetStatusPlainText' for custom error responses, and 'SetStatusRedirect' for seamless navigation control.
Illustrates runtime server introspection using the 'WebServer' object. This example demonstrates how to programmatically retrieve active server configuration, monitor live database queries via JSON status dumps, and inspect the compiled program cache for performance monitoring and troubleshooting.
Demonstrates robust state management and defense-in-depth strategies for web applications. This example showcases the use of 'Nonces' for session token generation and mandatory CSRF protection, illustrating how to manage secure cookies with HttpOnly and Strict flags to prevent unauthorized access and cross-site attacks.
Showcases modern real-time communication patterns between the server and web clients. This example demonstrates using 'WebResponse.SetContentEventStream' to maintain persistent HTTP connections and the 'WebServerSentEvent' class to broadcast live data updates to multiple subscribers using a name-based channel pattern.
Illustrates fractal generation and iterative complex arithmetic. This example demonstrates nested 'for' loops, floating-point math, and character-based mapping to render a visual representation of the Mandelbrot set in ASCII.
Demonstrates bitmap manipulation and image encoding/decoding. This example showcases the 'TPixmap' type for pixel-level access, converting images to PNG and JPEG data streams, and performing round-trip transformations between binary data and visual objects.
Explores high-performance vector mathematics using the native 'TVector' type. This example demonstrates vector addition, scalar multiplication, dot products ('*'), and cross products ('^'), highlighting the language's optimized support for 3D graphics and physics calculations.