Provides full feature support for the WALTER language.

This extension is in early development. Many features are not ready yet, and some bugs are to be expected. Moreover, it deliberately introduces a few restrictions on certain language constructs to make WALTER more consistent and less error-prone, so you may see a number of diagnostic messages (i.e., errors) in your code, even if it is fully functional. All of this is explained further in this document.

Supported features

Syntax Validation

Hover tooltips

• Hover over any keyword to see its documentation.

Autocompletion / IntelliSense

• Code completions are suggested as you type.
• You can also open the suggestions menu by pressing Ctrl + Spacebar.

Lexical syntax highlighting

Expanding and shrinking the selection

• Press Alt + Shift + Right or Alt + Shift + Left to expand or shrink the selection, respectively.
• This can help you determine the exact boundaries of expressions.

Comment toggling

• Press Ctrl + / to toggle comments for the current line or selection.

Custom folding regions

• Use ;--- and ;- to mark the start and end of a custom folding region, respectively.

Linter

Code linting is the automated process of analyzing source code to find formatting errors, stylistic inconsistencies, and potential bugs.

You can disable any linting rule by adding "walter.linter.<ruleName>": false, to your settings.json file.

• noTrailingSpaces - disallows whitespace characters (spaces or tabs) at the end of a line.
• noDefCommands - disallows the use of the def command, as it introduces ambiguity when reading source code.
• noDashesInIdentifiers - prevents common errors where dashes are mistaken for subtraction, such as set a -b.
• noSingleEquals - enforces using == instead of = for equality checks to maintain code consistency.

Other

• Bracket/quote autoclosing.
• Syntax highlighting in Markdown fenced code blocks.

Planned features

• Actions:
  • Expand/collapse - automatically breaks a long set statements down into a nicely formatted hierarchy of separate expressions, and collapses it back.
• Jump to definition (for user variables and macros).
• Find all references to an identifier.
• Semantic folding (for macro, layout, and long statements).
• Semantic syntax highlighting (for macro parameters and user variables).
• Hover tooltips:
  • Human-readable diagnostic messages.
  • User documentation comments (JSDoc style or similar).
• Semantic error checking:
  • Unknown identifiers.
  • Unclosed macro/layout statements.
• Refactoring:
  • Rename user variables and macros across the document.
• Auto-formatting:
  • Indentation for layout and macro blocks.
  • Removal trailing whitespace.
• Color picker for AABBGGRR values.
• Linting:
  • noDeadCode - unused variables and macros, and dead branches.
  • noMixedWhitespace - mixing tabs and spaces in indentation or comments.
  • noMixedQuotes - using different types of quotation marks across the document.
  • noConsecutiveBlankLines - prevents excessive consecutive blank lines.
  • consistentIdentifierCase - enforces camelCase or snake_case for user identifiers.
  • noLayoutElementLookalikes - e.g., tcp.label.myVar.

Known issues and limitations

• Only a restricted set of characters is allowed in identifier names:
  • WALTER allows variables to have almost any name, no matter how unusual - for example, ..., -4.0, ,, or "my var". However, to improve code readability and prevent potential errors, only characters commonly used in programming languages are allowed: the first character must be a letter or underscore, and subsequent characters may be letters, digits, underscores, or dots.
  • The # character is temporarily permitted in identifiers (see the next section).
• Macros (macro ... endmacro) are not supported yet:
  • Implementing full macro support will take some time. If the highlighting of false errors inside macros is distracting, you can disable the parser. To do so, add "walter.enableParser": false to your settings.json.
  • For now, all ## are treated as ordinary identifier characters.
• All places where strings are semantically expected accept only strings. Likewise, all places where identifiers are semantically expected accept only identifiers:
  • Use layout "Black" "folder-name" instead of layout "Black" folder-name.
  • Use set my_var 1 instead of set "my var" 1.