Class description
gl-shader is a predicate class comprising values returned by OpenGL to represent shader objects. The following words are provided for creating and manipulating these objects:
<gl-shader> - Compile GLSL code into a shader object
gl-shader-ok? - Check whether a shader object compiled successfully
check-gl-shader - Throw an error unless a shader object compiled successfully
gl-shader-info-log - Retrieve the info log of messages generated by the GLSL compiler
glDeleteShader - Invalidate a shader object

The derived predicate classes vertex-shader and fragment-shader are also defined for the two standard kinds of shader defined by the OpenGL specification.