def read(register):
"""
Get a byte from the keyboard and put it in the given register.
This blocks.
"""
ucode = assemble(SET, register, [0x9010])
ucode = until(ucode, (IFE, register, 0x0))
ucode += assemble(SET, [0x9010], 0x0)
ucode += assemble(SET, PC, POP)
return ucode
def memcpy():
"""
Copy A bytes from B to C. Clobbers A.
The copy is made back to front. No overlapping check is done.
"""
preamble = assemble(ADD, B, A)
preamble += assemble(ADD, C, A)
# Top of the loop.
ucode = assemble(SUB, A, 0x1)
ucode += assemble(SUB, B, 0x1)
ucode += assemble(SUB, C, 0x1)
ucode += assemble(SET, [C], [B])
ucode = until(ucode, (IFN, A, 0x0))
# And return.
ucode += assemble(SET, PC, POP)
return preamble + ucode
def memcmp():
"""
Put a length in A, two addresses in B and C, and fill A with whether
they match (non-zero) or don't match (zero).
"""
# Save X.
preamble = assemble(SET, PUSH, X)
preamble += assemble(SET, X, 0x0)
preamble += assemble(ADD, B, A)
preamble += assemble(ADD, C, A)
# Top of the loop.
ucode = assemble(SUB, B, 0x1)
ucode += assemble(SUB, C, 0x1)
ucode += assemble(IFE, [B], [C])
ucode += assemble(BOR, X, 0xffff)
ucode = until(ucode, (IFN, A, 0x0))
ucode += assemble(SET, A, X)
ucode += assemble(XOR, A, 0xffff)
# Restore X.
ucode += assemble(SET, X, POP)
ucode += assemble(SET, PC, POP)
return preamble + ucode
# Deep primitives.
ma.prim("read", read(A))
ma.prim("write", write(A))
# Top of the line: Go back to the beginning of the string.
ucode = assemble(SET, B, 0x0)
ucode += assemble(SET, C, ma.workspace)
# Read a character into A.
ucode += call(ma.asmwords["read"])
ucode += assemble(SET, [C], A)
ucode += assemble(ADD, B, 0x1)
ucode += assemble(ADD, C, 0x1)
# If it's a space, then we're done. Otherwise, go back to reading things from
# the keyboard.
ucode = until(ucode, (IFN, 0x20, [C]))
ucode += assemble(SET, C, ma.workspace)
ma.prim("word", ucode)
preamble = assemble(SET, C, 0x0)
ucode = assemble(MUL, C, 10)
ucode += assemble(SET, X, [A])
ucode += assemble(SUB, X, ord("0"))
ucode += assemble(ADD, C, X)
ucode += assemble(ADD, A, 0x1)
ucode += assemble(SUB, B, 0x1)
ucode = until(ucode, (IFE, B, 0x0))
ma.prim("snumber", preamble + ucode)
# Compiling words.
