Lush.md

Lush a modern take on literate programming

blurb

Lush intends to be a modern take on literate programming. ASTs are the reference representation of programs/modules. Rich surface syntax (susy), involving typefaces and font weights, provides a rich primary notation. The secondary notation, syntax highlighting, is orthogonal to the primary one and is still supported. Editing is mostly done in a structural way à la synthesizer using stunts, a redesign of textmate snippets As a result we could do away with parsing. To not be too disruptive to users, we should eventually support it at least at granular enough level, the expression level.

A purely textual susy is called a vanilla susy. The original susy of a given language is called its legacy susy. An input susy is a vanilla susy not designed for legibility but as a reminder of how to use stunts.

AST as a reference representation (a2r2) will allow to track modifications at a fine granularity by tracking an AST node over time. Such a fine tracking is impossible with line based diff. Grit, a new tool, based on git will support a2r2 with line based diff when a2r2 is not available or as a backup when a2r2 is buggy.

As a consequence of a2r2, avscode extension adapted from codetour will stay in sync as the code change.

leste as a show case

As a show case, leste is a rich susy for svelte legacy susy that do away with cumbersome mustache notations which have become the norm in reactive template languages.

Prototyping leste

Read only leste

We prototype leste by unparsing AST generated from svelte code. We create a modified svelte.dev site to show case leste. The unparser is written in ts but a special slang will be designed for that task.

Read write leste

We edit leste code using structural editing. Stuctural editing is based on stunt which is a redesign of snippets popularized by textMate

Short term consequences

Using svelte.dev to develop leste means the editor will initially be codemirror based. We will probably adapt and extend svelte.dev to be leste based and support extension like vscode does. FileTree.svelte wouls be the base for an explorer panel in a sidebar. A git extension would allow a source control with grit. We may even partially integrate, the leste editor, the leste based explorer and grit source control panel into vscode as webviews. But we don't want to go further. It should be a stepping stone toward real vscode support.

To support vscode we will eventuall need to use a modified monaco editor component. The vanilla editor supports only monospace font