+# Overview #
+
+This folder contains a library of useful functions written in VVhitespace.
+Standard include guards are used with `cpp` to include the stdlib in user
+programs. For an example, see `examples/hello-stdlib`.
+
# Reservations #
+Since all labels share a global namespace, the standard library makes the
+following reservations:
+
## Label ##
00000000 0xxxxxxx - reserved for stdlib function entry points
0xxxxxxx xxxxxxxx - reserved for private use by stdlib
1xxxxxxx xxxxxxxx - available for use in user programs
-## Heap ##
+## Heap and Pointers ##
+
+The first 16 heap addresses (`0-15`) are reserved when using the stdlib.
+Within that reservation, heap[0] is used by `random` and heap[15] is used
+by `spewreg`. The remaining 14 locations, heap[1]-heap[14] are used as
+general-purpose registers.
- The first 256 heap addresses are reserved when using the stdlib.
+By convention, functions which return a pointer will use the address `0` to
+represent a `NULL` pointer.
# Entry Points #
The following labels are entry points to stdlib functions. Read the
header comment for each function to learn the call and return stack.
- stdio.pvvs:
- 1000 - print string from stack
- 1001 - print string from heap
+ 000xxx - reserved
+ 001xxx - core functions
+ 1000 ----- printf (stdio.pvvs)
+ 1001 ----- print number from stack (stdio.pvvs)
+ 1010 ----- stackrotate (stack.pvvs)
+ 010xxx - math functions
+ 10000 ----- random (math.pvvs)
+ 10001 ----- absolute value (math.pvvs)
+ 011xxx - heap functions
+ 11000 ----- memset (heap.pvvs)
+ 11001 ----- memcpy (heap.pvvs)
+ 11010 ----- memrand (heap.pvvs)
+ 11011 ----- memcmp (heap.pvvs)
+ 11100 ----- memsrch (heap.pvvs)
+ 11101 ----- <empty>
+ 11110 ----- slurp (heap.pvvs)
+ 11111 ----- spew (heap.pvvs)
+ 100xxx - string functions
+ 100000 ----- strlen (string.pvvs)
+ 101xxx - unassigned
+ 110xxx - conversion functions
+ 111xxx - debug functions
+ 111000 ----- dump heap (debug.pvvs)
+ 111001 ----- dump stack (debug.pvvs)
+ 1xxxxxx - reserved for less common entry points
+ 1000000 ----- slurp registers (heap.pvvs)
+ 1000001 ----- spew registers (heap.pvvs)
+ 1000010 ----- print sign of number (stdio.pvvs)
+ 1000011 ----- print magnitude of number (stdio.pvvs)
+ 1000100 ----- print string from stack (stdio.pvvs)
+ 1000101 ----- print string from heap (stdio.pvvs)
# Misc #
00001000 xxxxxxxx - for use by 1000
00001001 xxxxxxxx - for use by 1001
+ ...etc