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