# Understanding Marko 6

## The Language

### Templating
- Tags
- Text + Placeholders
- Escaped/Unescaped placeholders
- Attributes
- Attributes are JavaScript values
- Default `value` Attribute
- Syntax Precedent: [BBCode](https://en.wikipedia.org/wiki/BBCode)'s parameterized tags (e.g.`[url=]`)
- Tag Variables
- Tag Parameters
- [Syntax Precedent](https://twitter.com/MarkoDevTeam/status/1540362487039762434?s=20): Rust's Closure Parameters, Ruby's Block Arguments, Handlebars' Block Parameters

### Components

###

### Client-side Code

- `<script>`

### State, Events, & Lifecycle

- Assigning to tag variables

### Async Data

### Context

## The Compiler

- Parser
- defining the syntax in context free grammar
- iterates over the source string character by character
- emits events which are used to build an ast
- an ast is a tree of pojos that represent the syntactic structure of the code
- see in the playground (todo)
- only has a surface-level understanding of JavaScript expressions
- passes those expression strings to babel to get ast nodes for the JavaScriptdoesn't
- Migrator
- Transformers
- Translator
- Generator

## The Runtime

Marko's runtime is not directly interacted with, but it can be helpful to understand the code your template compiles to.

https://hackmd.io/3kot0iwbQmGufWAQYMc5sQ

### Browser

#### Signals

##### Types
- basic
- source
- the entry points into the reactive graph
- notifies subscribers when the value changes
- derivation
- knows how to derive its own value
- receiver
- a derived value that receives its next value from its provider
- used at the boundary of components
- can only have one provider
- kindof like a mix between computations and sources
- subscription
- the sinks in the reactive graph
-
- other
- closure
- receiverDispatch
- dynamicSubscribers

#### Helpers
#### Templates & Cloning
#### Scope

Rather than relying on closures, all functions are hoisted to the module level and read data from a shared scope array. Each component operates on a subsection of the scope array. Components read/write from/to known indexes in the array (relative to the offset of their subsection). There is a scope array created for the root and every dynamic part of the component tree (<if>, <for>).

### Server

### Resuming