mq-dap 0.8.2

Debug Adapter Protocol implementation for mq
Documentation

Debug Adapter Protocol implementation for mq.

Usage

Command Line

Start the DAP server (typically done automatically by your editor):

# Start the DAP server
mq-dbg

# Debug a specific query file
mq-dbg query.mq input.md

Debugging Features

Once connected to a DAP client:

  1. Set Breakpoints: Click in the gutter or use your editor's breakpoint command
  2. Conditional Breakpoints: Only stop when an mq expression evaluates truthy, e.g. x > 3
  3. Hit Count Breakpoints: Only stop once the hit count condition is met. A bare number, e.g. 3, is shorthand for hit_count >= 3; otherwise it's evaluated as an mq expression with hit_count bound to the current hit count, e.g. hit_count >= 3 && x == 1
  4. Logpoints: Log a message instead of stopping; uses mq's own ${expr} string interpolation syntax, e.g. x is ${x}. ${self} yields the current pipeline value and ${$VAR} reads the environment variable VAR
  5. Exception Breakpoints: Enable "Uncaught Exceptions" in your editor's breakpoints pane to automatically pause when a query raises an error that isn't caught by try/catch
  6. Start Debugging: Launch the debugger with your query file
  7. Step Through Code: Use step over, step in, and step out commands
  8. Inspect Variables: Hover over variables or view them in the variables pane
  9. Watch Expressions: Add mq expressions to your editor's watch pane to re-evaluate them against the current scope every time execution stops
  10. View Call Stack: See the current execution stack in the call stack pane

Example Debug Session

# Create a query file
echo '.h | let y = to_text() | breakpoint() | y' > query.mq

# Start debugging
mq-dbg query.mq input.md

Development

Building from Source

git clone https://github.com/harehare/mq
cd mq
cargo build --release -p mq-dap

Running Tests

cargo test -p mq-dap

Support

License

Licensed under the MIT License.