group() statement

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Summary

The group() statement defines a set of rules to be processed together.

Syntax

group(groupName)
group(groupName) using keys
group(groupName) readonly

Parameters

groupName

: The unique name of the group, which can be referenced by use() statements.

The group() statement tells Keyman to start a new set of rules. Keyman supports three sorts of groups: key processing groups, read-only groups, and context processing groups. Key processing groups can include context checking, but context processing groups cannot include key checking. Read-only groups, like context processing groups, cannot include key checking. Keyman will use first the group specified in the begin statement, and move from there onto other groups.

To tell Keyman that the group should include key processing, you should include the using keys section of the statement; if that is omitted, the group checks only the context. The keystroke will remain the same during processing; you can have many groups that each use using keys, and the keystroke will be the same for all of them. The key section of a rule (including the + sign) is not valid for context processing groups.

Read-only groups

Read-only groups are new in Keyman 15. They are used primarily from NewContext and PostKeystroke entry points, and indicate that text output is not permitted from rules within the group. The purpose of these groups is typically to change the current layer of the touch keyboard, or perform similar state updates.

use() statements in a read-only group may only reference other read-only groups.

An implicit context statement is added to the front of every rule output in a read-only group, if it is not already present, to ensure that the input context is not modified. As it is not legal to have an empty output, you may use the context statement, not the nul statement on the right-hand side of an otherwise empty output.

In a read-only group, only the following output statements are permitted:

• call() - the custom function must not attempt to do any output
• context - only at the start of the output
• use() - use other readonly groups
• set()
• reset()
• save()

Examples

Example: Using group()

See Casing Support for a more comprehensive example of readonly groups.

group(main) using keys
  + [K_K] > U+0E01

group(syllablecheck)
  any(cons) any(vowel) any(cons) > context $nbsp

group(nextLayer) readonly
  '. ' > layer('shift')

Platforms

The group() statement can be used in keyboards on all platforms.

Windows	macOS	Linux	Desktop web	Mobile web	iOS	Android
✔	✔	✔	✔	✔	✔	✔

Version history

• The group construct was introduced in Keyman 3.0.
• The readonly group type was introduced in Keyman 15.0.

See also

• Using groups
• Casing support
• use() statement