# 12. render engine for web
Date: 2021-11-27
## Status
2021-11-27 proposed
2021-12-14 accepted
## Context
Sample:
- [https://github.com/ledge-framework/engine](https://github.com/ledge-framework/engine)
### Mathematics
/// https://katex.org/
/// use: https://www.mathjax.org/
``A x^2 + B x + C = 0``
### Comments
```
/// some comments
```
### Link relations
```
<entry_type>:<entry_id> "<entry_title>" -> <entry_type>:<entry_id> "<entry_title>"
```
```
note:0001 "title" -> content:0001 "2222"
note:0002 -> title
```
exact link
[[note:0001 "markdown-syntax"]]
ambiguous link
[["title"]]
page link
### Admonition
```
!!! note "An optional title"
Here is something you should pay attention to.
```
### Auto Todo
```
>>> todo "title"
do something
```
### Code
#### interactive code
// like: https://juliadocs.github.io/Documenter.jl/stable/showcase/#Running-interactive-code
Input:
```@example("java")
code_typed(sqrt, (Float64,))
```
Output:
```
```
#### repl code
run step by steps for repl languages
```@repl("repl") #1
using Statistics
xs = collect(1:10)
median(xs)
sum(xs)
```
`#1` to tag code, can be auto insert
```@repl_block("javascript")
```
#### auto code connect
```@connect
```
## Decision
Decision here...
## Consequences
Consequences here...