v5.1.0

5.1.0 - August 2025

This verion introduces a new selection of IDL Tutorials! These come as a collection of notebooks to help new users get up and running. In the IDL sidebar, you'll see a new section called "IDL Tutorials" with language-specific content.

With this change, we have also migrated the ENVI and IDL Example notebooks under the tutorials section.

Add a new auto-complete for block statements (i.e. if-then-begin) that functions much better compared to what we had. If there are any weird cases, or cases for block auto-complete that are missing, let us know and we can add them in.

Add a new sidebar entry to launch a session of ENVI and IDL. Requires an ENVI license and that you are using the IDL that is packaged with ENVI.

With the extension including GitHub Copilot integration, we have changed the extension so that it always activates in VSCode. Otherwise tools in Agent mode through GitHub Copilot would fail to run as our extension was not started.

Tweak hanging indent for procedures and procedure methods to use the first comma as the syntax we align to.

Fix an issue with catching standalone expressions where the problem would be incorrectly reported for chained property access.

Fix docs issues with colorbar() function not having all properties for keywords.

Fix docs issue where "ipm" was an unknown structure and would throw fake errors when using the static methods on the class.

Fixed an issue where IDL would show an error message about being unable to check the version if you had an IDL_STARTUP file specified that generated output.

Potentially fix an issue with auto-complete that would occur sometimes with code blocks.

Updated type parsing to support older code that used the name of the functions to create arrays as array types. We now map types such as "bytarr" to the proper IDL types of "Array" for full type/auto complete support.

Tweak notebook formatting that removes the trailing space at the end of cells. When you have many cells, this adds empty space that's not always needed or helpful.

v5.0.0

5.0.0 – July 2024

This release introduces a significant evolution in extension functionality, warranting the major version bump to 5.0.0.

⚠️ IDL 9.2 Dependency Notice

Some features introduced in this release depend on IDL 9.2, which is scheduled for release in July–August 2025. If you are not using IDL 9.2, these not all features will not be available.

---

The IDL Machine

With IDL 9.2, IDL now offers native integration with VSCode, bringing substantial improvements in performance and user experience.

• Faster startup and more responsive command execution

• Pause support is now fully functional on Windows

• Debugging shows better information about variables and their values

• Debugging workflow, and inputting commands in the debug console, has been completely re-worked for a more streamlined user experience and consistent keyboard focus

• Improved detection of when IDL is idle and ready for input

• Internal commands are excluded from command history

• Support for the read procedure (interactive user input) in the VSCode Debug Console and IDL Notebooks

• Enhanced progress reporting:

  • Native integration with IDL Notebooks

  • Cleaner output in the VSCode Debug Console

VSCode will automatically detect whether your IDL version supports these new features. The legacy debugger remains available for compatibility with older IDL versions and continues to work with both debug sessions and notebooks.

Note: The status bar (bottom-left of VSCode) will no longer display a custom prompt unless you're using IDL 9.2 or newer. This was necessary to streamline the new integration.

---

🤖 GitHub Copilot Integration

We've added initial support for GitHub Copilot in Agent Mode, enabling AI-powered interactions with IDL.

Available Actions:

• Start an IDL session

• Execute IDL code

• Create and run IDL Notebooks

• Launch ENVI

• Open files in ENVI

This marks our first step toward AI-assisted development in IDL. More capabilities will follow and feedback is welcome!

---

🌐 Web Extension Support

We now provide a lightweight version of the extension for the web-based version of VSCode.

Current Features:

• Syntax highlighting

• File association for .pro, .sav, and related files

• View support for IDL Notebooks

⚠️ This version does not support advanced language features such as auto-completion, hover help, or code execution.

Let us know if you'd like to see more features supported in the web version.

---

Fixes and Improvements

• Windows-specific fix: Resolved an issue where IDL's path was incorrectly set when no workspace was open, potentially causing slow startup.

• Notebook stability: No longer reports false errors when stopping a cell mid-execution.

• Cancellation handling: User actions like code execution now correctly respond to cancellations, preventing misleading error messages.

• Format-on-save: Fixed an issue where saving twice was required to trigger formatting.

• Formatting supports hanging indent: There's a new option in the formatter that allows you to enable hanging indent instead of the default block indent.

• Formatting with syntax errors: Improved handling of two scenarios where formatting would run when it shouldn't and would break your code.

• Outline now enables sticky headers: The outline has been updated to provide a sticky header showing you what routine you are working inside of

• CLI progress handling:

  • IDL Notebooks now mimic terminal output

  • VSCode Debug Console shows progress updates on new lines (due to inherent limitations)

• Notebook auto-print logic: Corrected auto-detection of implied print for consecutive lines.

• Startup checks: Directory validation for IDL now occurs when starting a session, not during extension startup.

• Autocomplete improvements: Property and keyword documentation in hover and auto-complete lists are now alphabetically sorted for easier navigation.

• Syntax highlighting: Enhanced for commands like .compile, with proper support for strings, comments, and theme-friendly styling.

• Hover help: Fixed a typo in task file documentation.

• ENVI + Notebooks: Starting ENVI UI in a notebook now disables graphics embedding in that cell to prevent blank/empty outputs. For best results, use a dedicated cell to start ENVI and separate cells for visual output. issue where saving twice was required to trigger formatting.

• Syntax highlighting and method detection: Fixed an issue where we would not properly highlightor parse procedure and function methods when in case/switch statements.

• Legacy Documentation Parsing: Updated the docs parsing for older style code comments to support a wider range of parameters that we parse (i.e. data type, direction) and multi-line starter blocks of docs

• Logical Operator Detection: When using compile option idl3, we now detect and warn about certain operators being used. These have custom code actions to fix and also get fixed with formatting on save

• Notebook Variable Detection: Fixed an issue where IDL Notebooks would incorrectly report a variable as undefined when it was, in fact, defined.

Other Bug Fixes

Fixed a parsin error where we would confuse case/switch if statements and methods

Manually updated some documentation to account for missing/invalid keywords that were actually correct.

v5.0.0-rc1

5.0.0. Beta 1

This release introduces a significant evolution in extension functionality, warranting the major version bump to 5.0.0.

⚠️ IDL 9.2 Dependency Notice

Some features introduced in this release depend on IDL 9.2, which is scheduled for release in July–August 2025. If you are not using IDL 9.2, these not all features will not be available.

---

The IDL Machine

With IDL 9.2, IDL now offers native integration with VSCode, bringing substantial improvements in performance and user experience.

• Faster startup and more responsive command execution

• Pause support is now fully functional on Windows

• Debugging shows better information about variables and their values

• Debugging workflow, and inputting commands in the debug console, has been completely re-worked for a more streamlined user experience and consistent keyboard focus

• Improved detection of when IDL is idle and ready for input

• Internal commands are excluded from command history

• Support for the read procedure (interactive user input) in the VSCode Debug Console and IDL Notebooks

• Enhanced progress reporting:

  • Native integration with IDL Notebooks

  • Cleaner output in the VSCode Debug Console

VSCode will automatically detect whether your IDL version supports these new features. The legacy debugger remains available for compatibility with older IDL versions and continues to work with both debug sessions and notebooks.

Note: The status bar (bottom-left of VSCode) will no longer display a custom prompt unless you're using IDL 9.2 or newer. This was necessary to streamline the new integration.

---

🤖 GitHub Copilot Integration

We've added initial support for GitHub Copilot in Agent Mode, enabling AI-powered interactions with IDL.

Available Actions:

• Start an IDL session

• Execute IDL code

• Create and run IDL Notebooks

• Launch ENVI

• Open files in ENVI

This marks our first step toward AI-assisted development in IDL. More capabilities will follow and feedback is welcome!

---

🌐 Web Extension Support

We now provide a lightweight version of the extension for the web-based version of VSCode.

Current Features:

• Syntax highlighting

• File association for .pro, .sav, and related files

• View support for IDL Notebooks

⚠️ This version does not support advanced language features such as auto-completion, hover help, or code execution.

Let us know if you'd like to see more features supported in the web version.

---

Fixes and Improvements

• Windows-specific fix: Resolved an issue where IDL's path was incorrectly set when no workspace was open, potentially causing slow startup.

• Notebook stability: No longer reports false errors when stopping a cell mid-execution.

• Cancellation handling: User actions like code execution now correctly respond to cancellations, preventing misleading error messages.

• Format-on-save: Fixed an issue where saving twice was required to trigger formatting.

• Formatting supports hanging indent: There's a new option in the formatter that allows you to enable hanging indent instead of the default block indent.

• Formatting with syntax errors: Improved handling of two scenarios where formatting would run when it shouldn't and would break your code.

• Outline now enables sticky headers: The outline has been updated to provide a sticky header showing you what routine you are working inside of

• CLI progress handling:

  • IDL Notebooks now mimic terminal output

  • VSCode Debug Console shows progress updates on new lines (due to inherent limitations)

• Notebook auto-print logic: Corrected auto-detection of implied print for consecutive lines.

• Startup checks: Directory validation for IDL now occurs when starting a session, not during extension startup.

• Autocomplete improvements: Property and keyword documentation in hover and auto-complete lists are now alphabetically sorted for easier navigation.

• Syntax highlighting: Enhanced for commands like .compile, with proper support for strings, comments, and theme-friendly styling.

• Hover help: Fixed a typo in task file documentation.

• ENVI + Notebooks: Starting ENVI UI in a notebook now disables graphics embedding in that cell to prevent blank/empty outputs. For best results, use a dedicated cell to start ENVI and separate cells for visual output. issue where saving twice was required to trigger formatting.

• Syntax highlighting and method detection: Fixed an issue where we would not properly highlightor parse procedure and function methods when in case/switch statements.

• Legacy Documentation Parsing: Updated the docs parsing for older style code comments to support a wider range of parameters that we parse (i.e. data type, direction) and multi-line starter blocks of docs

• Logical Operator Detection: When using compile option idl3, we now detect and warn about certain operators being used. These have custom code actions to fix and also get fixed with formatting on save

• Notebook Variable Detection: Fixed an issue where IDL Notebooks would incorrectly report a variable as undefined when it was, in fact, defined.

Other Bug Fixes

Fixed a parsin error where we would confuse case/switch if statements and methods

Manually updated some documentation to account for missing/invalid keywords that were actually correct.

4.7.1

Fixed an issue with the IDL Webview that showed a blank tab when opened. This affect things like the profiler in the extension.

If there are unexpected errors in the webview, we now try to catch them and alert the user. Errors should be printed to the logs and a button will appear to make it easy to report an issue if this happens in the future.

Added basic support for symbolic links and managing files that have symbolic links. This includes tests for baseline user experience as well.

When we encounter a file with a symbolic link, we report problems for the true file on disk (not the path including the link). This means you won't see problems actively reported for the file if you edit it as a link.

Resolved an issue where task file generation wouldn't update your original code with a main level program if you didn't have one.

v4.7.0

4.7.0 - November 2024

Added the ability to statically determine the return types for functions and function methods that don't have documentation. This means that, for the following example, we properly detect that we return an IDL Long (because of compile_opt idl2):

function myFunc
  compile_opt idl2
  return, 42 ; or is it 84?
end

This marks the first step of an iterative process to automatically detect types from code when you don't have strict documentation. We can also, in the future, check to make sure actual return values match docs.

In order to detect types from your code, we had to make some pretty big changes to the language server in order to properly resolve types that don't come from documentation. With that, if you notice any odd behaviors or issues, please reach out to us on Github to let us know of any problems. For large workspaces, such as the IDL lib folder, this means it will take about 1.5-2.5 more seconds to parse your code (depending on complexity of your code base and how many routines are called in other files).

In order for our type detection functionality to work correctly, we did have to revert a change we recently made to reduce long-term memory usage of the language server.

However, we did tweak the in-memory cache for parsed files to optimize performance. We no longer copy complex data structures which adds a 10-15% performance improvement parse speed and helps reduce memory usage.

Optimized the language server change detection process to focus on only routines/globals that have changed and not everything in a file (change detection is a process for validating usage of routines in other files when the source definition is updated).

Changed the error message reported when we can't find a structure definition. This adds some context for why we might not know about a structure definition to help users who aren't following best practices/standards.

Fixed a bug where code actions were not appearing in notebook cells.

Fixed an issue where code actions, in notebooks, incorrectly fixed issues on the first line of a cell.

Fixed an issue where the language server was not correctly detecting pointers being de-referenced. This caused false errors for "standalone expressions" to be reported and for formatting to not function correctly.

Update extension docs with the latest version of node.js that we require (to work around language server crashes).

Updated hover help packaged with the extension with ENVI 6.1, IDL 9.1, and ENVI Deep Learning 3.0.1 docs

Tweak the logic for how we respond to settings changes for problems that we report. This change means, as you change which problems you want reported in real-time, the problems tab in VSCode will add/remove problems that you do/don't want to see. Previously you would need to restart VSCode for the changes to take effect.

Improved the logic when checking if we report problems or not for a file to account for the folder on IDL's path being recursive or not.

Fixed an issue where, when disabling problems from duplicate routines, they were still being reported.

Updating our formatting logic to add a final line feed or carriage return after the last line of a file when formatting your code.

Potential fix to resolve canonical (true) filepaths when you have symbolic links in your workspace or on IDL's search path. This should fix a problem where the same file was incorrectly having two paths and reporting duplicate problems.

v4.6.2

Changed the language server startup process to remove all files from memory after initial startup. This reduces RAM by 0.25-0.5 GB of memory after startup, depending on the volume of code in workspaces and on your path.

When we clean up the language server (happens every 5 minutes), we now check our in-memory cache and remove any files that haven't been accessed recently. Helps reduce overall RAM when VSCode is open for long periods at a time.

Changed the way that the language server sends work to the threads that parse code. The main difference is that we no longer send the parsed version of code back to the main thread which we were doing.

For large files, this had a significant impact on perceived performance as the worker threads could get locked serializing and de-serializing objects (also leads to more memory usage). Now, large files like slicer3.pro which are included in the IDL installation, provide auto-complete and hover help in about ~0.5 seconds instead of 5+ seconds.

Fixed an issue where, from the JSON settings editor, a valid extension setting would be highlighted as being an incorrect value.

Fixed an issue where the "don't ask again" options didn't honor your choice for using IDL as the formatter.

v4.6.1

Added layer controls to the Notebook Map.

• Generic title for each layer (raster/vector)
• Slider to make transparent or not

Layers have a handle which allows you to use drag and drop to re-order them. As you re-order, the map updates with changes.

Notebook maps now listen to theme changes from VSCode and, when swapping between light and dark themes, the basemap will update to match the theme of VSCode (light map for light theme; dark map for dark theme)

Fixed an issue where we weren't properly detecting keywords for obj_destroy when a custom object class had a ::cleanup method present

Fixed a bug with auto-complete where, instead of variables, arguments, or functions, you would end up with procedures being suggested inside of a procedure call.

Similar to call_function() and obj_new(), add special auto-complete for call_procedure to give you the list of procedure names with string literals

Fixed a bug where we were incorrectly detecting standalone expressions and reporting as problems.

Fixed a parsing issue where we would not correctly determine the end of ternary operators which could report errors incorrectly in your code.

Re-worked auto-complete to function the same way as hover help. Now, we determine types of features to send from one of our worker threads and then the main thread builds out the completion items. The advantage of this is that we can now send back documentation and other information (which doesn't exist in our worker threads).

v.4.60

Fixed an issue where we open a file that we have stopped in, even if it is compiled as a SAVE file. Now, only PRO files will be jumped to.

Fixed an issue where, if you have a comment block before and after a routine definition, the second comment block is picked. We now only use the comment block after a routine definition if we did not find one just before.

Fixed an issue where documentation after a routine definition wasn't properly reporting problems.

For both of the problems above, and for documentation inside of a routine, the interior comments must be on the next line after the definition otherwise they will not be detected. If this breaks existing behavior for you, let us know and we can change it back!

Resolved an issue where, when routine definitions changed, problems were not properly detected as they should be. Example: changing the name of a keyword should have an error appear in any file that used the old keyword.

Notebooks now support compiling files! If a cell only has comments and compile statements, then it will be executed as a batch file. This allows you to merge notebooks and traditional editing/creation of PRO code.

Updated the "Hello World" IDL Notebook example with this new behavior.

Improve auto-complete for executive commands.

For .compile we now have auto-complete for files known to the language server.

Created a new concept called a Routine Definition File for IDL. These files allow developers, who deliver code as SAVE files or as DLLs/DLMs, to provide documentation so that other users get hover help, auto-complete, and the ability to create notebooks automatically from examples in the docs.

See the new documentation page here for more information.

Fixed an issue where we were not correctly detecting unclosed quotes when there was an escaped quote within the content of the string.

Re-work the toolbar for animations in IDL Notebooks. The new toolbar uses the same colors/style as the sidebar and will look good on most themes. There was an issue, after a library update, where colors for high contrast themes did not work with the slider and have now been fixed.

Notebook maps (requires ENVI) now have a button that will reset the view to the initial state. Helpful in case you zoom out or lose the location of your imagery while zooming/panning around.

v4.5.1

Continuing with our story of IDL Notebook user experience, each session of notebook now gets it's own instance of IDL! This means a few things:

• You can now run more than one IDL Notebook in parallel! This makes it easy to crank through data or multi-task to your heart's content.

• Each session of IDL notebook is sand-boxed and a separate process. This means notebooks won't interact with each other.

• When you close an IDL Notebook, the associated IDL Kernel is automatically stopped

• A new sidebar entry in the Notebook section, allows you to stop all IDL Notebook Kernels

Remove a false error report when you stop IDL (terminate the process) while it is running

Fixed an error where we were not automatically returning from the main level when you compiled a main level program.

Fixed an issue in IDL Notebooks where, once ENVI is started, a notebook no longer can embed multiple graphics in a single notebook cell.

When ENVI is started, as long as the UI is not present, we now embed direct graphics. If the ENVI UI is open, we don't embed direct graphics.

v4.5.0

4.5.0 - May 2024

New-and improved IDL Notebook user experience!

• When compiling cells, we don't show you the output from compiling to focus on what runs

• The paths for notebook cells have been cleaned up and are now easy to read (before they had IDs in the names of the paths)

• Notebook cells now offer implied print! For main level programs (i.e. cells by default), we detect and automatically print variables, outputs from function calls, and expressions like "2 + 42". You can see some examples of this in our sample IDL Notebook included with the extension.

• Variables that will be printed have a special semantic token highlighting applied to them to make it clear it is not being interpreted as a procedure. This depends on your VSCode theme, but should either look like other variables or stands out compared to procedure calls.

• After running a notebook cell, we check to see if there is any output. If there is no output, we do not create notebook cell output. Previously we always added output to cells, even if there wasn't anything to track.

Fixed an issue where we incorrectly reported an error when using the property index signature to retrieve a property. This affected statements of the form "struct.(0).(0)"

Add icons for the languages that we contribute to the extension

Add human-readable names for the languages that we contribute

Fixed an edge case when reporting that a variable cannot be indexed with the !null type

Type detection now properly handles the following cases:

• Any statement using && or || will return boolean type

• Any statement using a logical operator should return the correct type (i.e. eq, ne, le). For example: [1,2,3] eq 5 should give a type of Array<Boolean>. This supports lists, hashes, orderedhashes, and dictionaries.

These type changes help fix scenarios where we were incorrectly reporting errors for extension users.

The extension now automatically detects when you have code that is "standalone" which needs to be assigned to a value (or have a value assigned to it).

When running IDL through the debug console, we now properly catch stops/breakpoints that aren't a result of manually sending commands to IDL. This supports use cases where widget/UI applications are running and hit a stop or breakpoint in a callback routine.

Moved the following features out of preview since there have been no reported issues:

Added the ability to convert a notebook to a PDF! This requires an additional extension called ":"Markdown PDF", which you will be prompted to install. This includes:

• A new sidebar entry for PDF generation and a button in the top-right of the notebook to generate a PDF

• When you click the button to create a PDF, as long as your notebook is saved to disk, it will create Markdown, open it, and start the PDF generation process

• Once finished, it closes the Markdown file

• The Markdown and PDF file use the same base name as your notebook. Meaning if your notebook is called "My-notebook.idlnb" you will have a "My-notebook.md" and "My-notebook.pdf" file generated in the same folder

• You do need to save your notebook to disk so we have a path to write the Markdown and PDF files