Visual Alias

Visual Alias is a Visual Studio Code extension that displays alternative text for certain words or patterns, without changing the original text. For example, in LaTeX, the following code

\begin{equation}
    G_{\mu \nu} + \Lambda g_{\mu \nu} = \frac{8 \pi G}{c^4} T_{\mu \nu}
\end{equation}

can be configured to be displayed as

\begin{equation}
    G_{μ ν} + Λ g_{μ ν} = \frac{8 π G}{c^4} T_{μ ν}
\end{equation}

The original code for each symbol is revealed when the caret touches the symbol.

The functionality of this extension is similar to that of the Prettify Symbols Mode and Symbol Masks extensions, but they both seem to be unmaintained, and are no longer working properly, although a new version of Symbol Masks is working. This extension is intended to be an alternative for these extensions.

Features

• Display alternative text for certain words or patterns, without changing the original text.

Extension Settings

This extension contributes the following settings:

• visualAlias.patterns: An array of pattern groups. For example, a pattern group can be

  {
      "language": "latex",
      "defaultSuffix": "(?![a-zA-Z])",
      "patterns": [
          "\\\\alpha/α",
          // ...
      ]
  }

  • The language field specifies the language ID that the pattern group applies to. It can be set to "*" to apply the replacement rules to all languages, or can be an array of language IDs.

  • The optional defaultSuffix field specifies a regular expression that is appended to each pattern. Similarly, the optional defaultPrefix field can be used to specify a regular expression that is prepended to each pattern.

  • The patterns field is an array of patterns to be replaced. Each pattern can be a string of the form "pattern/replacement", where pattern is a regular expression, and replacement is a string. Note that special characters in the pattern, such as \, / and [, must be escaped, so for example, to match \alpha in the document, the pattern should be "\\\\alpha/α". One can also use "/pattern/replacement" to disable the default prefix and suffix.

  • Instead of a string "pattern/replacement", a pattern can also be an object of the form

    {
        "pattern": "pattern",
        "replacement": "replacement",
        "color": "#ff0000",
        "fontWeight": "bold",
        // ...
    }

    which can apply specified styles to the replacement text. The supported styles are backgroundColor, border, color, fontFamily, fontSize, fontStyle, fontWeight, textDecoration.

  • Additionally, the optional defaultStyle field can be used to specify a default style for all patterns in the group. The default style is overridden by the styles specified in the individual patterns.

  The default value is a list of patterns for latex.

• visualAlias.maxLineCount (default: 10000): The maximum number of lines to process. If a document has more lines than this value, the extension will not process the document.

• visualAlias.maxLineLength (default: 1000): The maximum number of characters in a line to process.

Usage notes

• When using with LaTeX to replace mathematical symbols, using a suitable font with math support, such as JuliaMono, either as a fallback font or in the fontFamily setting, can greatly improve the appearance of the replacement text.