# Apple II Memory Map
This is the TypeScript binding to a database of Apple II special addresses intended to be used with language servers. The central element is the file `map.json` which maps addresses to a set of descriptive strings.
## Map Records
The map records correspond to the interface
```ts
interface AddressInfo {
brief: string | undefined,
ctx: string | undefined,
desc: string,
label: string | undefined,
note: string | undefined,
subctx: string | undefined,
type: string
}
```
The whole database is retrieved as a `Map` using
```ts
get_all() : Map<string,AddressInfo>
```
To get a single record use
```ts
get_one(addr: number): AddressInfo | undefined
```
The argument `addr` can range from -32767 to 65535. As an example `get_one(0xfded)` will give
```js
{
brief: 'Print character in A',
desc: 'Invoke output routine whose address is in (56). Usually prints character in A.',
label: 'COUT',
type: 'ROM routine'
}
```
## AddressInfo Fields
* `brief`: short description suitable for display in a selection box
* `ctx`: notes on limiting context, such as hardware requirements, applicability to given language, etc.
* `desc`: long description suitable for hovers
* `label`: suggested assembler label
* `note`: any other notes
* `subctx`: notes on sub context, e.g., specific aspect of a language
* `type`: data type (e.g. `word`) or operation type (e.g. `ROM routine`, `soft switch`)
## Multi-context Records
The `map.json` file uses logic expressions to delineate information by context, e.g., `ctx` might have the value `"Applesoft | Integer BASIC"`. The TypeScript interface provides a function to parse the logic and produce an array of records, with each element corresponding to a given context:
```ts
get_one_and_split(addr: number): Array<AddressInfo> | undefined
```
If there is no splitting of the `ctx` field, no other fields will be split. It is not required to use this function. If `get_one` is used instead, downstream will receive the logic expressions, which can be parsed in any manner desired.