valid-feature-tag? ( tag -- ? )

Vocabulary

fonts.shaping.private

Inputs

tag

an object

Outputs

?

an object

Definition

USING: kernel math sequences strings ;

IN: fonts.shaping.private

: valid-feature-tag? ( tag -- ? )
    dup string? [
        [ length 4 = ] [ [ [ 32 >= ] [ 126 <= ] bi and ] all? ]
        bi and
    ] [ drop f ] if ;