By default, text editors using GtkSourceView (such as Gedit and Mousepad) don't highlight .asm files. The solution by Drew Noakes is to download a GtkSourceView language definition file for x86 assembly language into .local/share/gtksourceview-3.0/language-specs/. I know how to make a language definition file per GNOME.org's GtkSourceView documentation.
However, I routinely work with multiple instruction sets, each of which needs different highlighting rules:
- MOS 6502 assembly (for NES, Commodore 64, Apple II, Atari 8-bit, etc.)
- Sharp SM83 assembly (for Game Boy)
- Zilog Z80 assembly (for MSX, ZX Spectrum, Game Gear, etc.)
- ARM assembly (for Game Boy Advance, etc.)
All of them may use .s or .asm as a file name suffix, so the <metadata><property name="globs">*.s</property></metadata> appears inadequate to distinguish them.
Is there a good way to indicate the instruction set of an assembly language file to a GtkSourceView editor? In particular, is there a better way than locally defining an Internet media type for each ISA using shared-mime-info, using <magic>, and ensuring that all collaborators also have the same locally defined Internet media type?