test.sid

# Read a file and print its contents using C standard I/O via the FFI.
#
# Parse the stdio header at compile time and bake the CFuncSig values into the
# compiled output.  lib_name is derived from the filename stem ("stdio").
# load_scope @! then immediately unpacks the resulting struct into scope, so
# every function becomes directly addressable as a label.

"/usr/include/stdio.h" c_load_header @!
load_scope @!
"/usr/include/stdlib.h" c_load_header @!
load_scope @!

# Link the actual shared library at runtime under the name "stdio" (matching
# the stem used above).  The list form lets us load libc.so.6 but register it
# under a different key.

["libc.so.6" "stdio"] c_link_lib !
["libc.so.6" "stdlib"] c_link_lib !


# Open README.md for reading
"README.md" "r" fopen! clone!

# declare and clone buffer size
4096 clone!

# Allocate and clone the string buffer
malloc! types.str ptr_cast! clone!

# Reorganize so the clones for cleanup are at the bottom of the stack
# (file and buf on bottom, then file+buf_size+buf
($1 $5 $4 $3 $2)!
# After that we can build the loop body we actually want
($1 $2 $3 fgets!)

# Condition: clone so the null-arm can drop the spare; the any-arm consumes the
# original.  To call printf(fmt, [args]) we first wrap the result in a list,
# push the format string, then swap with ($2 $1)! to get [fmt [result]] order.
(
  clone! {
    $types.null: (drop! false),
    $types.any: ([$1] "%s" ($2 $1)! printf! 0 eq! not!),
  } match!
)
do_while!

# Cleanup: stack values should be in the right order so just run
free!
fclose!
0 eq! assert! # Check retval from fclose