//: So far you can have global variables by not setting default-space, and
//: local variables by setting default-space. You can isolate variables
//: between those extremes by creating 'surrounding' spaces.
//:
//: (Surrounding spaces are like lexical scopes in other languages.)
void test_surrounding_space() {
run(
// location 2 in space 1 (remember that locations 0 and 1 are reserved in all
// spaces) refers to the space surrounding the default space, here 20.
"def main [\n"
// prepare default-space address
" 10:num/alloc-id, 11:num <- copy 0, 1000\n"
// prepare default-space payload
" 1000:num <- copy 0\n" // alloc id of payload
" 1001:num <- copy 5\n" // length
// prepare address of chained space
" 20:num/alloc-id, 21:num <- copy 0, 2000\n"
// prepare payload of chained space
" 2000:num <- copy 0\n" // alloc id of payload
" 2001:num <- copy 5\n" // length
// actual start of this recipe
" default-space:space <- copy 10:space\n"
// later layers will explain the /names: property
" 0:space/names:dummy <- copy 20:space/raw\n"
" 2:num <- copy 94\n"
" 2:num/space:1 <- copy 95\n"
"]\n"
"def dummy [\n" // just for the /names: property above
"]\n"
);
CHECK_TRACE_CONTENTS(
// chain space: 1000 + (alloc id) 1 + (length) 1
"mem: storing 0 in location 1002\n"
"mem: storing 2000 in location 1003\n"
// store to default space: 1000 + (alloc id) 1 + (length) 1 + (index) 2
"mem: storing 94 in location 1004\n"
// store to chained space: (contents of location 1003) 2000 + (alloc id) 1 + (length) 1 + (index) 2
"mem: storing 95 in location 2004\n"
);
}
//: If you think of a space as a collection of variables with a common
//: lifetime, surrounding allows managing shorter lifetimes inside a longer
//: one.
:(replace{} "int space_base(const reagent& x)")
int space_base(const reagent& x) {
int base = current_call().default_space ? (current_call().default_space+/*skip alloc id*/1) : 0;
return space_base(x, space_index(x), base);
}
int space_base(const reagent& x, int space_index, int base)