Feature - Local macOS dictionary as a source

[Rican7]

Currently, define uses all remote (online) sources. A local, expandable dictionary is available on macOS, which would be a great source if it was accessible.

Unfortunately, it seems that the only way to access the dictionary's data is through Core Services, which would require Cocoa bindings to Go and native-compilation (think cgo). There may be another way around this, though.

Also, the only public APIs that exist return the definition in a formatted string format, not in a structured model, which would be a nightmare (if not potentially impossible) to consistently parse.

More information here (for later reference):

• https://developer.apple.com/documentation/coreservices/dictionary_services
• http://nshipster.com/dictionary-services/
• https://github.com/mattt/DictionaryKit
• https://gist.github.com/mattt/9453538
• https://apple.stackexchange.com/questions/90040/look-up-a-word-in-dictionary-app-in-terminal
• https://discussions.apple.com/thread/2679911

[Rican7]

is it possible to make an offline copy if these online sources?

An offline copy of the entirety of a language dictionary? Not that I know of.

If it was possible, it'd likely be expensive (API calls), or massive.

[earthboundkid]

On my computer, if I load ~/Library/Caches/com.apple.DictionaryServices/DictionaryCache.plist it looks like this:

The first dictionary is one I installed myself. Looking at the next one:

$ tree $(pbpaste)
/System/Library/AssetsV2/com_apple_MobileAsset_DictionaryServices_dictionaryOSX/1700888691b981116bc46e57553cf4e4f41f2bc3.asset/AssetData/Traditional\ Chinese\ -\ English\ Idioms.dictionary
└── Contents
    ├── Info.plist
    └── Resources
        ├── Body.data
        ├── DefaultStyle.css
        ├── EntryID.data
        ├── EntryID.index
        ├── KeyText.data
        ├── KeyText.index
        ├── ar.lproj
        │   └── InfoPlist.strings
        ├── ca.lproj
        │   └── InfoPlist.strings
        ├── cs.lproj
        │   └── InfoPlist.strings
        ├── da.lproj
        │   └── InfoPlist.strings
        ├── de.lproj
        │   └── InfoPlist.strings
        ├── el.lproj
        │   └── InfoPlist.strings
        ├── en.lproj
        │   └── InfoPlist.strings
        ├── en_AU.lproj
        │   └── InfoPlist.strings
        ├── en_GB.lproj
        │   └── InfoPlist.strings
        ├── es.lproj
        │   └── InfoPlist.strings
        ├── es_419.lproj
        │   └── InfoPlist.strings
        ├── fi.lproj
        │   └── InfoPlist.strings
        ├── fr.lproj
        │   └── InfoPlist.strings
        ├── fr_CA.lproj
        │   └── InfoPlist.strings
        ├── he.lproj
        │   └── InfoPlist.strings
        ├── hi.lproj
        │   └── InfoPlist.strings
        ├── hr.lproj
        │   └── InfoPlist.strings
        ├── hu.lproj
        │   └── InfoPlist.strings
        ├── id.lproj
        │   └── InfoPlist.strings
        ├── it.lproj
        │   └── InfoPlist.strings
        ├── ja.lproj
        │   └── InfoPlist.strings
        ├── ko.lproj
        │   └── InfoPlist.strings
        ├── ms.lproj
        │   └── InfoPlist.strings
        ├── nl.lproj
        │   └── InfoPlist.strings
        ├── no.lproj
        │   └── InfoPlist.strings
        ├── pl.lproj
        │   └── InfoPlist.strings
        ├── pt.lproj
        │   └── InfoPlist.strings
        ├── pt_PT.lproj
        │   └── InfoPlist.strings
        ├── ro.lproj
        │   └── InfoPlist.strings
        ├── ru.lproj
        │   └── InfoPlist.strings
        ├── sk.lproj
        │   └── InfoPlist.strings
        ├── sv.lproj
        │   └── InfoPlist.strings
        ├── th.lproj
        │   └── InfoPlist.strings
        ├── tr.lproj
        │   └── InfoPlist.strings
        ├── uk.lproj
        │   └── InfoPlist.strings
        ├── vi.lproj
        │   └── InfoPlist.strings
        ├── zh_CN.lproj
        │   └── InfoPlist.strings
        ├── zh_HK.lproj
        │   └── InfoPlist.strings
        └── zh_TW.lproj
            └── InfoPlist.strings

41 directories, 46 files

Poking around online, it seems like these dictionaries were originally plain XML, and then at some point Apple changed it to being a custom compressed format. Some put an old version of Apple's Dictionary Development Kit on Github: https://github.com/SebastianSzturo/Dictionary-Development-Kit Maybe looking a that would tell you how to open the .data files.