//: Arrays contain a variable number of elements of the same type. Their value
//: starts with the length of the array.
//:
//: You can create arrays of containers, but containers can only contain
//: elements of a fixed size, so you can't create containers containing arrays.
//: Create containers containing addresses to arrays instead.
//: Tests in this layer often explicitly setup memory before reading it as an
//: array. Don't do this in general. I'm tagging exceptions with /raw to
//: avoid warnings.
:(scenario copy_array)
# Arrays can be copied around with a single instruction just like numbers,
# no matter how large they are.
recipe main [
1:number <- copy 3:literal # length
2:number <- copy 14:literal
3:number <- copy 15:literal
4:number <- copy 16:literal
5:array:number <- copy 1:array:number/raw # unsafe
]
+mem: storing 3 in location 5
+mem: storing 14 in location 6
+mem: storing 15 in location 7
+mem: storing 16 in location 8
:(scenario copy_array_indirect)
recipe main [
1:number <- copy 3:literal # length
2:number <- copy 14:literal
3:number <- copy 15:literal
4:number <- copy 16:literal
5:address:array:number <- copy 1:literal
6:array:number <- copy 5:address:array:number/deref
]
+mem: storing 3 in location 6
+mem: storing 14 in location 7
+mem: storing 15 in location 8
+mem: storing 16 in location 9
//: disable the size mismatch check since the destination array need not be initialized
:(after "bool size_mismatch(const reagent& x, const vector<double>& data)")
if (x.types.at(0) == Type_ordinal["array"]) return false;
:(after "long long int size_of(const reagent& r)")
if (r.types.at(0) == Type_ordinal["array"]) {
assert(SIZE(r.types) > 1);
// skip the 'array' type to get at the element type
return 1 + Memory[r.value]*size_of(array_element(r.types));
}
//:: To access elements of an array, use 'index'
:(scenario index)
recipe main [
1:number <- copy 3:literal # length
2:number <- copy 14:literal
3:number <- copy 15:literal
4:number <- copy 16:literal
5:number <- index 1:array:number/raw, 0:literal # unsafe
]
+mem: storing 14 in location 5
:(scenario index_direct_offset)
recipe main [
1:number <- copy 3:literal # length
2:number <- copy 14:literal
3:number <- copy 15:literal
4:number <- copy 16:literal
5:number <- copy 0:literal
6:number <- index 1:array:number/raw, 5:number # unsafe
]
+mem: storing 14 in location 6
:(before "End Primitive Recipe Declarations")
INDEX,
:(before "End Primitive Recipe Numbers")
Recipe_ordinal["index"] = INDEX;
:(before "End Primitive Recipe Implementations")
case INDEX: {
//? if (Trace_stream) Trace_stream->dump_layer = "run"; //? 1
reagent base = canonize(current_instruction().ingredients.at(0));
//? trace(Primitive_recipe_depth, "run") << "ingredient 0 after canonize: " << base.to_string(); //? 1
long long int base_address = base.value;
assert(base.types.at(0) == Type_ordinal["array"]);
reagent offset = canonize(current_instruction().ingredients.at(1));
//? trace(Primitive_recipe_depth, "run") << "ingredient 1 after canonize: " << offset.to_string(); //? 1
vector<double> offset_val(read_memory(offset));
vector<type_ordinal> element_type = array_element(base.types);
//? trace(Primitive_recipe_depth, "run") << "offset: " << offset_val.at(0); //? 1
//? trace(Primitive_recipe_depth, "run") << "size of elements: " << size_of(element_type); //? 1
assert(offset_val.at(0) >= 0);
assert(offset_val.at(0) < Memory[base_address]*size_of(element_type) + 1);
long long int src = base_address + 1 + offset_val.at(0)*size_of(element_type);
trace(Primitive_recipe_depth, "run") << "address to copy is " << src;
trace(Primitive_recipe_depth, "run") << "its type is " << Type[element_type.at(0)].name;
reagent tmp;
tmp.set_value(src);
copy(element_type.begin(), element_type.end(), inserter(tmp.types, tmp.types.begin()));
products.push_back(read_memory(tmp));
break;
}
:(code)
vector<type_ordinal> array_element(const vector<type_ordinal>& types) {
return vector<type_ordinal>(++types.begin(), types.end());
}
:(scenario index_address)
recipe main [
1:number <- copy 3:literal # length
2:number <- copy 14:literal
3:number <- copy 15:literal
4:number <- copy 16:literal
5:number <- index-address 1:array:number/raw, 0:literal # unsafe
]
+mem: storing 2 in location 5
//:: To write to elements of containers, you need their address.
:(scenario index_indirect)
recipe main [
1:number <- copy 3:literal # length
2:number <- copy 14:literal
3:number <- copy 15:literal
4:number <- copy 16:literal
5:address:array:number <- copy 1:literal
6:number <- index 5:address:array:number/deref, 1:literal
]
+mem: storing 15 in location 6
:(before "End Primitive Recipe Declarations")
INDEX_ADDRESS,
:(before "End Primitive Recipe Numbers")
Recipe_ordinal["index-address"] = INDEX_ADDRESS;
:(before "End Primitive Recipe Implementations")
case INDEX_ADDRESS: {
reagent base = canonize(current_instruction().ingredients.at(0));
long long int base_address = base.value;
assert(base.types.at(0) == Type_ordinal["array"]);
reagent offset = canonize(current_instruction().ingredients.at(1));
vector<double> offset_val(read_memory(offset));
vector<type_ordinal> element_type = array_element(base.types);
assert(offset_val.at(0) >= 0);
assert(offset_val.at(0) < Memory[base_address]*size_of(element_type) + 1);
long long int result = base_address + 1 + offset_val.at(0)*size_of(element_type);
products.resize(1);
products.at(0).push_back(result);
break;
}
//:: compute the length of an array
:(scenario array_length)
recipe main [
1:number <- copy 3:literal # length
2:number <- copy 14:literal
3:number <- copy 15:literal
4:number <- copy 16:literal
5:number <- length 1:array:number/raw # unsafe
]
+mem: storing 3 in location 5
:(before "End Primitive Recipe Declarations")
LENGTH,
:(before "End Primitive Recipe Numbers")
Recipe_ordinal["length"] = LENGTH;
:(before "End Primitive Recipe Implementations")
case LENGTH: {
reagent x = canonize(current_instruction().ingredients.at(0));
if (x.types.at(0) != Type_ordinal["array"]) {
raise << "tried to calculate length of non-array " << x.to_string() << '\n';
break;
}
products.resize(1);
products.at(0).push_back(Memory[x.value]);
break;
}