You can declare variables like:
OGL.vec3f something;
But generally it would be used with OpenGlShader's uniform helpers like
shader.uniforms.mouse = OGL.vec(mouseX, mouseY); // or OGL.vec2f if you want to be more specific
This is still extremely experimental, not very useful at this point, and thus subject to change at random.
Added December 7, 2021. Not yet stable.
A static container of experimental types and value constructors for opengl 3+ shaders.