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Writing and Running Grapa Scripts

Syntax Reminders

  • Every statement and every block (including after closing braces) must end with a semicolon (;).
  • Use block comments (/* ... */) or line comments (// ...). # comments are not supported.
  • To append to arrays, use the += operator (not .push() or .append()).
  • See Syntax Quick Reference for more.

Writing .grc Files

  • Use .grc files for Grapa scripts and tests.
  • End every statement and block with a semicolon.
  • Use block comments for documentation and explanations.
  • Use .echo() for output.
  • Use while loops (not for).
  • Access arrays/lists with [index], objects with .get("key").
  • See Examples for idiomatic code patterns.

Example .grc File

/* Example Grapa script */
input = "Hello world\nGoodbye world\nHello again";
matches = input.grep("Hello");
matches.echo();

Running .grc Files

  • Use the -f option to run a Grapa script file:
  • Windows: .\grapa.exe -q -f "my_script.grc"
  • Linux/Mac: ./grapa -q -f "my_script.grc"
  • Use -c for short, inline commands (not for files).
  • Always use -f for multi-line scripts and tests.

Creating and Using .grz Files

  • .grz files are compiled Grapa scripts for faster execution.
  • To create a .grz file, use the Grapa compiler or the $sys().compile() function: 
    compiled = $sys().compile("my_script.grc");
$file().set("my_script.grz", compiled);
  • To run a .grz file:
  • Windows: .\grapa.exe -q -f "my_script.grz"
  • Linux/Mac: ./grapa -q -f "my_script.grz"
  • .grz files are portable and can be distributed for faster loading and execution.
  • See GRZ Format Specification for technical details.

Best Practices

  • Validate your .grc scripts with known-good examples before running in production.
  • Use .grz files for deployment or performance-critical scenarios.
  • Use Testing to ensure your scripts behave as expected.

See also