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Advanced Topics

This section covers advanced features and techniques in Grapa for power users and those extending the language or pushing its performance boundaries.

Meta-Programming and Execution Trees

  • $OP Objects: Grapa supports direct manipulation of execution trees via $OP objects, enabling dynamic code generation, compilation, and execution at runtime.
  • Dynamic Evaluation: Use $sys().eval() and $sys().compile() for advanced meta-programming patterns.
  • Reference: See Operator: Function and System Functions.

Executable BNF and Language Design

  • Executable BNF: Grapa's $RULE system goes beyond traditional parsing - it's a complete programming language for defining languages.
  • Dynamic Grammar: Modify and extend the language grammar at runtime for custom syntax and DSLs.
  • Three-Phase Processing: Input → Compilation → Execution Tree → Runtime Evaluation.
  • Isolated Rule Execution: Execute custom rules without affecting the main language grammar.
  • Lexical Flags: Use $& enclosures to activate special lexer processing for XML/HTML content.
  • Reference: See Language Design with Executable BNF for comprehensive guide, Isolated Rule Execution for ETL and domain-specific processing.

Custom Grammar and BNF

  • Grammar Design: Grapa allows you to define and extend its grammar using BNF-like rules, enabling custom language features and DSLs.
  • Language Extensibility: Define custom commands and functions that become part of the language syntax at runtime.
  • Multi-Syntax Support: Grapa can support multiple syntaxes (JSON, XML, HTML natively, SQL via example scripts) through its executable BNF architecture.
  • Lexical Processing: Use $& enclosures to activate special lexer processing for complex formats like XML/HTML.
  • Reference: See Language Syntax Extension for comprehensive documentation, Grammar Design for BNF details, and maintainer docs for implementation details.

Advanced System Functions

Performance Tuning and Parallelism

  • Parallel Operations: Use .map(), .filter(), and .reduce() with thread counts for parallel data processing.
  • Performance Optimization: For deeper performance tuning or engine internals, see the Deep Expert Implementation Overview.

Advanced Error Handling and Debugging

  • Error Handling: Use .iferr() for fallback, and advanced error patterns for robust scripts.
  • Debugging: Grapa provides a comprehensive debugging system with CLI and script-based control, component-specific targeting, session isolation, and proper stream separation (stdout/stderr). See Debugging in Grapa for complete documentation.

For Deep Experts and Contributors

See also