block_read

      filename: <string>

 The named file is read into the current fold and is marked as a block.

 The editor attempts to deduce the language of the file from its filename. If
 this fails, it assumes the file is of the same language as the current
 buffer. ie: if you are editing a "C" file and you write a file 'fred.asm',
 the file will be written with assembler reserved comments.

 eg:  block_read "macros.c"