HSL (Hamilton) Language Support for VS Code

A VS Code extension providing comprehensive language support for HSL (Hamilton Standard Language) — the programming language used for Hamilton liquid handling robots (VANTAGE, STAR, STAR-V, Nimbus, etc.). This extension brings modern IDE features to HSL development, including syntax highlighting, intelligent code completion, diagnostics, and snippets.

Contributors

• Huajiang Wei — GitHub · Lab Automation Forum

Features

Syntax Highlighting

Full HSL syntax highlighting with support for:

• Keywords and control flow statements
• Data types and modifiers
• Operators and punctuation
• Single-line (//) and block (/* */) comments
• String literals and numeric constants

Intelligent Code Completion

• Built-in Functions: Auto-complete for VENUS's extensive built-in function set (math, string manipulation, file I/O, and more)
• Library Functions: Auto-complete for functions found in installed HSL libraries
• Element Methods: Context-aware completion for object methods (sequence, device, file, timer, etc.)
• Inline Docs & Signature Help: Hover documentation and parameter hints for completions and function calls

Real-Time Diagnostics

The extension analyzes your code as you type and flags common issues:

• Invalid operator combinations (e.g., =+ and =-, which do not exist in HSL)
• Function call argument-count validation with clear, descriptive messaging
• Variable declarations not at the top of their code block (HSL requirement)
• General syntax validation with clear error messages and suggestions

Variable Declaration Scope Rule

In HSL, local variables must be declared at the beginning of a code block ({ ... }).

• A function or namespace body is a code block.
• Declarations may appear after #include directives and/or namespace wrappers, as long as declarations are the first executable statements within that specific code block.
• A nested { ... } inside a function is also a new code block.
• Declarations are valid at the top of that nested block, even if they appear later in the outer function.
• Declarations after executable statements in the same block are invalid.

Code Snippets

Pre-built templates for common HSL patterns — type a prefix and press Tab:

Supported File Extensions

Library Discovery and Search Paths

This extension mirrors the standard HSL/VENUS library discovery model. Because library locations are governed by the Hamilton installation and HSL runtime conventions, the extension does not provide a setting to change library roots.

The extension discovers HSL libraries using the typical Hamilton installation library locations, such as:

• C:\Program Files (x86)\Hamilton\Library\...

It also resolves #include "..." directives commonly used in HSL libraries, including:

• Absolute paths
• UNC paths
• Library-root-relative includes under the Hamilton library directory

Note: IntelliSense for library functions depends on the libraries being present on the machine where VS Code is running.

Language Reference

Keywords

• Control Flow: if, else, for, while, do, loop, switch, case, default, break, continue, return
• Exception Handling: onerror, goto, abort, throw, try, catch
• Declarations: namespace, function, method, dialog, class, struct
• Modifiers: private, public, protected, static, const, global, synchronized
• Parallel Execution: fork, join, lock, unlock
• HSL Scheduler: activity, actionblock, executoronly, oncancelaction, oncanceltask, resource, reschedule, schedule, scheduleronly, schedulerprompt, workflow

Data Types

• Primitives: variable, string, integer, float, char, short, long
• Objects: object, sequence, device, resource, dialog, timer, event, file
• Constants: hslTrue, hslFalse

Built-in Function Categories

The extension provides auto-completion for 100+ built-in HSL functions, including:

• Math: Sin, Cos, Tan, Exp, Log, Sqrt, Abs, Round, Floor, Ceiling
• String: StrGetLength, StrMid, StrFind, StrReplace, StrTrimLeft, StrTrimRight
• Conversion: IStr, FStr, IVal, FVal, StrConcat
• Sequence: GetTotal, SetTotal, Add, Remove, GetAt, SetAt
• File I/O: Open, Close, Read, Write, ReadString, WriteString
• System: Trace, Sleep, Wait, MessageBox, GetFunctionName, GetTime
• Error Handling: err.Raise, err.Clear, err.GetId, err.GetDescription

Requirements

• VS Code 1.85.0 or later
• Hamilton VENUS 4 or later

You can download and install Hamilton VENUS 4 from Hamilton's official post on the forum, or download it directly here.

Getting Started

1. Install the extension from the VS Code Marketplace
2. Open (or create) a file with a .hsl, .hs_, or .sub extension
3. Start coding — syntax highlighting activates automatically
4. Use snippets by typing a prefix (e.g., hslfunc) and pressing Tab
5. Explore completions by pressing Ctrl+Space

Known Limitations / Non-Goals

• This extension is not a full HSL compiler; parsing and analysis are heuristic and best-effort.
• Diagnostics may not perfectly match every VENUS translator edge case.
• Some IntelliSense and discovery features depend on HSL libraries being installed locally in expected system paths.
• Initial indexing/discovery may take longer on first run; subsequent runs are typically faster due to caching.
• There is currently no debugger or Run Control integration in VS Code; programs must be executed using Hamilton Run Control (HxRun.exe).

Help & Support

For additional help and support, check out the following resources:

• Wiki: Visit the GitHub Wiki for documentation and guides.
• Forum: Learn more about Hamilton HSL programming on the Lab Automation Forum.
• Issues: Report bugs or request features on the Issues page.

Contributing

Contributions are welcome. Visit the GitHub repository to:

• Report bugs or request features
• Submit pull requests
• View the source code

GitHub: https://github.com/zdmilot/VS-Code-Extension-for-HSL