context

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Summary

The context statement reproduces part or all of the context buffer.

Syntax

... > context
... > context(offset)
... context(offset) > ...

Parameters

offset

The character offset in the context from which the output character is selected, starting at 1. The index increments for each character or statement found, with one caveat:

• outs() statements are expanded prior to calculating the offset.

If the context() statement is in the context (third form above), the offset must be less than the offset of the context() statement itself.

The offset cannot reference a nul or if statement, as both of these are non-character statements.

Description

The context statement reproduces the context stored from the rule match, or a single character of it, into the output. If you do not need to change the context, then use the context statement as the first element of your rule output, as this allows Keyman to skip deletion and re-insertion of the context into the text store of the active document.

A single character from the context can be output (on the right-hand side of a rule) or matched (on the left-hand side of a rule) using the context() form.

Note that although the context() form can be used in the left-hand side of a rule, the context form cannot.

Examples

Example: Using context

c match a char from the 'cons' store, 'W' and any 'key', don't change the output
any(cons) "W" + any(key) > context index(keyout,3)

c when the user types 'context', change it to 'ox'
"contex" + "t" > context(2) context(6)     c outputs "ox"

c when a user types two identical consonants, delete one of them,
c on the next matching key from the 'key' store
any(cons) context(1) + any(key) > context(1) index(keyout, 3)

Platforms

The context statement can be used in keyboards on all platforms.

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

Version history

• Offset calculations for nul were documented in 18.0 along with bug fixes in Keyman Core.

• Support for notany() together with context() added in KeymanWeb 14.0.

• The context(n) form was introduced in version 6.0.

• The context statement was introduced in Keyman 3.0.

See also

• if() statement
• outs() statement