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`config`

Query or define Murex runtime settings

Description

Rather than Murex runtime settings being definable via obscure environmental variables, Murex instead supports a registry of config defined via the config command. This means any preferences and/or runtime config becomes centralised and discoverable.

Usage

List all settings:

config -> <stdout>

Get a setting:

config get app key -> <stdout>

Set a setting:

config set app key value

<stdin> -> config set app key

config eval app key { -> code-block }

Define a new config setting:

config define app key { json }

Reset a setting to it’s default value:

!config app key

config default app key

Examples

Using eval to append to an array (in this instance, adding a function name to the list of “safe” commands)

» function foobar { -> match foobar }
» config eval shell safe-commands { -> append foobar }

Detail

With regards to config, the following terms are applied:

app

This refers to a grouped category of settings. For example the name of a built in.

Other app names include

shell: for “global” (system wide) Murex settings
proc: for scoped Murex settings
http: for settings that are applied to any processes which use the builtin HTTP user agent (eg open, get, getfile, post)
test: settings for Murex’s test frameworks
index: settings for [ (index)

key

This refers to the config setting itself. For example the “app” might be http but the “key” might be timeout - where the “key”, in this instance, holds the value for how long any HTTP user agents might wait before timing out.

value

Value is the actual value of a setting. So the value for “app”: http, “key”: timeout might be 10. eg

» config get http timeout
10

scope

Settings in config, by default, are scoped per function and module. Any functions called will inherit the settings of it’s caller parent. However any child functions that then change the settings will only change settings for it’s own function and not the parent caller.

Please note that config settings are scoped differently to local variables.

global

Global settings defined inside a function will affect settings queried inside another executing function (same concept as global variables).

Directives

The directives for config define are listed below.

DataType
Description"
Global
Default
Options
Dynamic
- Dynamic Read
- Dynamic Write

"DirectiveName": json data-type (default value)

Where “default value” is what will be auto-populated if you don’t include that directive (or “required” if the directive must be included).

DataType

Value: str (required)

This is the Murex data-type for the value.

Description"

Value: str (required)

Description is a required field to force developers into writing meaning hints enabling the discoverability of settings within Murex.

Global

Value: bool (default: false)

This defines whether this setting is global or scoped.

All Dynamic settings must also be Global. This is because Dynamic settings rely on a state that likely isn’t scoped (eg the contents of a config file).

Default

Value: any (required)

This is the initialized and default value.

Options

Value: array (default: null)

Some suggested options (if known) to provide as autocompletion suggestions in the interactive command line.

Dynamic

Value: map of strings (default: null)

Only use this if config options need to be more than just static values stored inside Murex’s runtime. Using Dynamic means autocomplete get app key and autocomplete set app key value will spawn off a subshell running a code block defined from the Read and Write mapped values. eg

# Create the example config file
out "this is the default value" |> example.conf

config define example test5 %{
    Description: This is only an example
    DataType: str
    Global: true
    Dynamic: {
        Read: '{
            open example.conf
        }'
        Write: '{
            |> example.conf
        }'
    },
    
    # read the config file to get the default value
    Default: ${open example.conf}
}

It’s also worth noting the different syntax between Read and Default. The Read code block is being executed when the Read directive is being requested, whereas the Default code block is being executed when the JSON is being read.

In technical terms, the Default code block is being executed by Murex when config define is getting executed where as the Read and Write code blocks are getting stored as a JSON string and then executed only when those hooks are getting triggered.

Dynamic Read

Value: str (default: empty)

This is executed when autocomplete get app key is ran. The stdout of the code block is the setting’s value.

Dynamic Write