Instructions

LispKit Bytecode Instructions

Stack management

Instruction	Explanation
pop	Drops the top element from stack.
dup	Duplicates the top element on the stack.
swap	Swaps the top two elements on the stack.
alloc n	Pushes n undefined values onto the stack.
reset o,n	Replaces n values on the stack with the undefined value starting from frame pointer offset o.

Constants

Instruction	Explanation
push_undef	Pushes the undefined value onto the stack.
push_eof	Pushes the EOF value onto the stack.
push_null	Pushes value null (empty list) onto the stack.
push_true	Pushes value true onto the stack.
push_false	Pushes value false onto the stack.
push_fixnum n	Pushes the fixnum n onto the stack.
push_bignum bn	Pushes the bignum bn onto the stack.
push_rat r	Pushes the rational number r onto the stack.
push_bigrat br	Pushes the given bigrat number br onto the stack.
push_flonum x	Pushes the flonum x onto the stack.
push_complex cx	Pushes the complex number cx onto the stack.
push_char ch	Pushes the character ch onto the stack.
push_constant c	Pushes the constant from the constant pool at index c onto the stack.

Functions

Instruction	Explanation
make_closure n,f	Creates a new closure from a capture list and a code fragment. The capture list is created from the top n elements on the stack. f is an index into the list of code fragments of the currently executed code.
make_frame	Pushes a new stack frame onto the stack.
call n	Calls a procedure with n arguments.
tail_call n	Calls a procedure with n arguments. This instruction is used for tail calls and does not require a new frame to be pushed.
apply n	This instruction expects on the stack a function, n - 1 individual arguments and an additional list of arguments. apply pushes the elements of the list onto the stack as well and then applies the function to all arguments on the stack. The instruction puts the result of the function application onto the stack.
return	Returns from the currently executed procedure.
assert_arg_count n	Checks that there are exactly n arguments on the stack.
assert_min_arg_count n	Checks that there are at least n arguments on the stack.
collect_rest n	Collects the arguments exceeding n into a list.
compile	Compiles the expression on top of the stack creating a thunk (a procedure without arguments) which is left on top of the stack.

Macros

Instruction	Explanation
make_syntax	Pops a syntax transformer function off the stack, creates a special form from it and pushes it onto the stack.

Promises

Instruction	Explanation
make_promise n,f	Creates a promise on the stack whose value will be computed by executing a closure that consists of n captured variables (on the stack), and the code fragment at index f.
force	Forces the value of the promise on top of the stack. If the promise has been evaluated already, push the value onto the stack and skip the next instruction (which is typically a store_in_promise instruction).
store_in_promise	Stores the value on top of the stack in the promise of the second top-most value on the stack. The promise gets removed from the stack.

Variables

Instruction	Explanation
make_local_variable o	Creates a new variable, pops an expression from the stack and assignes the variable this expression as its initial value. The variable is then stored at the location specified by the frame pointer offset o.
make_variable_argument n	Creates a new variable and assignes the variable the expression at the location specified by the frame pointer offset o. The variable is then stored at the location specified by the frame pointer offset o; i.e. this instruction swaps a value on the stack with a variable with the same value.

Bindings

Instruction	Explanation
push_global c	TODO
set_global c	TODO
define_global c	TODO
push_captured d	TODO
push_captured_value d	TODO
set_captured_value d	TODO
push_local o	TODO
push_local_value o	TODO
set_local_value o	TODO

Control flow

Instruction	Explanation
branch i	TODO
branch_if i	TODO
branch_if_not i	TODO
and i	TODO
or i	TODO

Equivalences

Instruction	Explanation
eq	TODO
eqv	TODO
equal	TODO

Containers

Instruction	Explanation
list n	TODO
cons	TODO
car	TODO
cdr	TODO
vector n	TODO
list_to_vector	TODO
vector_append n	TODO
is_vector	TODO

Math

Instruction	Explanation
fx_plus	TODO
fx_minus	TODO
fx_mult	TODO
fx_div	TODO
fl_plus	TODO
fl_minus	TODO
fl_mult	TODO
fl_div	TODO

Miscellaneous

Instruction	Explanation
noop	TODO
push_current_time	TODO
display	TODO
newline	TODO