Schema Next Steps

[dendron-bot]

Source

• [[Schema Simplification Inline Children|dendron://private/scratch.2021.09.15.193745.schema-simplification-inline-children]]

Notes

General impression: I like the simplification proposal. It makes syntax less verbose and gives a clear visual about what nodes are used or not used.

Further thoughts:

tenants

Since schemas are a core part of the dendron language, lets take some time to make sure we start with the right goals in mind and work backward from tenants. See the typescript goals ¹ as a good starting point. Think of our landing page as the amazon press release. Schemas are the type system for general knowledge. How do we deliver on this promise?

Below I've listed a starting point below, adopted from the typescript design goals ¹

• goals:
  1. Identify constructs that are likely to be errors.
  1. Provide a structuring mechanism for knowledge bases built on markdown derived content
     1. Impose no runtime overhead on emitted programs
  2. Allow humans to author notes in recognizable markdown (should not lead to users having to embed XML like constructs in their notes)
  3. Produce a language that is composable and easy to reason about.
     1. Align with current and future ECMAScript proposals.
     1. Preserve runtime behavior of all JavaScript code.
  4. Avoid adding additional syntax to markdown
  5. Use a consistent, fully erasable, structural type system.
  6. Be a cross-platform development tool.
  7. Do not cause substantial breaking changes from Schema 2.0.
• non-goals
  1. Exactly mimic the design of existing languages. Instead, use the behavior of markdown and the intentions of note authors as a guide for what makes the most sense in the language.
     1. Aggressively optimize the runtime performance of programs. Instead, emit idiomatic JavaScript code that plays well with the performance characteristics of runtime platforms.
  2. Apply a sound or "provably correct" type system. Instead, strike a balance between correctness and productivity.
  3. Provide an end-to-end build pipeline. Instead, make the system extensible so that external tools can use the compiler for more complex build workflows.
     1. Add or rely on run-time type information in programs, or emit different code based on the results of the type system. Instead, encourage programming patterns that do not require 1. run-time metadata.
     1. Provide additional runtime functionality or libraries. Instead, use TypeScript to describe existing libraries.
  4. Introduce behaviour that is likely to surprise users. Instead have due consideration for patterns adopted by other commonly-used languages.

extensibility

One use case we want to support is making it easy for users to share, remix and built upon existing schemas. how do we make the schema design here compatible?

imports

How will [[imports|dendron://dendron.dendron-site/dendron.topic.schema#imports]] be supported? consider multi-vault scenarios

separating matching from behavior

one of the current limitations with schema imports is that you can't attach new behavior to existing matches. take the following example

• journal.yml

schemas:        
  - id: journal
    children: 
      - pattern: "[0-2][0-9][0-9][0-9]"
        title: year
        children: 
          - pattern: "[0-1][0-9]"
            title: month
            children: 
              - pattern: "[0-3][0-9]"
                title: day

for our user journals, we should support the ability to add templates and additional functionality to matches

• user.yml

imports:
  - journal
schemas:
  - id: user
    children:
      - name: kevin
        children:
          - schema: journal
            override:
              - id: day
                template: kevin.template
      - name: nickolay
          - schema: journal
            override:
              - id: day
                template: nickolay.template

rfc 12 - schema improvements

We have an existing schema improvement rfc, can we make sure the ideas from here can be incorporated into the new design -> [[Types|dendron://dendron.dendron-site/dendron.rfc.12-schema-improvements.types]]

Next Steps

• @nickolay-kondratyev - can you lay out a new RFC for schemas following the process [[here|dendron://dendron.dendron-site/dendron.rfc]] that elaborates on some of these points

Footnotes

1. TypeScript Design Goals · microsoft/TypeScript Wiki ↩ ↩²