diff options
Diffstat (limited to '031merge.cc')
| -rw-r--r-- | 031merge.cc | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/031merge.cc b/031merge.cc new file mode 100644 index 00000000..c56579a5 --- /dev/null +++ b/031merge.cc @@ -0,0 +1,227 @@ +//: Construct types out of their constituent fields. + +:(scenario merge) +container foo [ + x:num + y:num +] +def main [ + 1:foo <- merge 3, 4 +] ++mem: storing 3 in location 1 ++mem: storing 4 in location 2 + +:(before "End Primitive Recipe Declarations") +MERGE, +:(before "End Primitive Recipe Numbers") +put(Recipe_ordinal, "merge", MERGE); +:(before "End Primitive Recipe Checks") +case MERGE: { + // type-checking in a separate transform below + break; +} +:(before "End Primitive Recipe Implementations") +case MERGE: { + products.resize(1); + for (int i = 0; i < SIZE(ingredients); ++i) + for (int j = 0; j < SIZE(ingredients.at(i)); ++j) + products.at(0).push_back(ingredients.at(i).at(j)); + break; +} + +//: type-check 'merge' to avoid interpreting numbers as addresses + +:(scenario merge_check) +def main [ + 1:point <- merge 3, 4 +] +$error: 0 + +:(scenario merge_check_missing_element) +% Hide_errors = true; +def main [ + 1:point <- merge 3 +] ++error: main: too few ingredients in '1:point <- merge 3' + +:(scenario merge_check_extra_element) +% Hide_errors = true; +def main [ + 1:point <- merge 3, 4, 5 +] ++error: main: too many ingredients in '1:point <- merge 3, 4, 5' + +//: We want to avoid causing memory corruption, but other than that we want to +//: be flexible in how we construct containers of containers. It should be +//: equally easy to define a container out of primitives or intermediate +//: container fields. + +:(scenario merge_check_recursive_containers) +def main [ + 1:point <- merge 3, 4 + 1:point-number <- merge 1:point, 5 +] +$error: 0 + +:(scenario merge_check_recursive_containers_2) +% Hide_errors = true; +def main [ + 1:point <- merge 3, 4 + 2:point-number <- merge 1:point +] ++error: main: too few ingredients in '2:point-number <- merge 1:point' + +:(scenario merge_check_recursive_containers_3) +def main [ + 1:point-number <- merge 3, 4, 5 +] +$error: 0 + +:(scenario merge_check_recursive_containers_4) +% Hide_errors = true; +def main [ + 1:point-number <- merge 3, 4 +] ++error: main: too few ingredients in '1:point-number <- merge 3, 4' + +:(scenario merge_check_reflexive) +% Hide_errors = true; +def main [ + 1:point <- merge 3, 4 + 2:point <- merge 1:point +] +$error: 0 + +//: Since a container can be merged in several ways, we need to be able to +//: backtrack through different possibilities. Later we'll allow creating +//: exclusive containers which contain just one of rather than all of their +//: elements. That will also require backtracking capabilities. Here's the +//: state we need to maintain for backtracking: + +:(before "End Types") +struct merge_check_point { + reagent container; + int container_element_index; + merge_check_point(const reagent& c, int i) :container(c), container_element_index(i) {} +}; + +struct merge_check_state { + stack<merge_check_point> data; +}; + +:(before "End Checks") +Transform.push_back(check_merge_calls); // idempotent +:(code) +void check_merge_calls(const recipe_ordinal r) { + const recipe& caller = get(Recipe, r); + trace(9991, "transform") << "--- type-check merge instructions in recipe " << caller.name << end(); + for (int i = 0; i < SIZE(caller.steps); ++i) { + const instruction& inst = caller.steps.at(i); + if (inst.name != "merge") continue; + if (SIZE(inst.products) != 1) { + raise << maybe(caller.name) << "'merge' should yield a single product in '" << to_original_string(inst) << "'\n" << end(); + continue; + } + reagent/*copy*/ product = inst.products.at(0); + // Update product While Type-checking Merge + const type_tree* product_base_type = product.type->atom ? product.type : product.type->left; + assert(product_base_type->atom); + if (product_base_type->value == 0 || !contains_key(Type, product_base_type->value)) { + raise << maybe(caller.name) << "'merge' should yield a container in '" << to_original_string(inst) << "'\n" << end(); + continue; + } + const type_info& info = get(Type, product_base_type->value); + if (info.kind != CONTAINER && info.kind != EXCLUSIVE_CONTAINER) { + raise << maybe(caller.name) << "'merge' should yield a container in '" << to_original_string(inst) << "'\n" << end(); + continue; + } + check_merge_call(inst.ingredients, product, caller, inst); + } +} + +void check_merge_call(const vector<reagent>& ingredients, const reagent& product, const recipe& caller, const instruction& inst) { + int ingredient_index = 0; + merge_check_state state; + state.data.push(merge_check_point(product, 0)); + while (true) { + assert(!state.data.empty()); + trace("transform") << ingredient_index << " vs " << SIZE(ingredients) << end(); + if (ingredient_index >= SIZE(ingredients)) { + raise << maybe(caller.name) << "too few ingredients in '" << to_original_string(inst) << "'\n" << end(); + return; + } + reagent& container = state.data.top().container; + if (!container.type) return; // error handled elsewhere + const type_tree* top_root_type = container.type->atom ? container.type : container.type->left; + assert(top_root_type->atom); + type_info& container_info = get(Type, top_root_type->value); + switch (container_info.kind) { + case CONTAINER: { + // degenerate case: merge with the same type always succeeds + if (state.data.top().container_element_index == 0 && types_coercible(container, inst.ingredients.at(ingredient_index))) + return; + const reagent& expected_ingredient = element_type(container.type, state.data.top().container_element_index); + trace("transform") << "checking container " << to_string(container) << " || " << to_string(expected_ingredient) << " vs ingredient " << ingredient_index << end(); + // if the current element is the ingredient we expect, move on to the next element/ingredient + if (types_coercible(expected_ingredient, ingredients.at(ingredient_index))) { + ++ingredient_index; + ++state.data.top().container_element_index; + while (state.data.top().container_element_index >= SIZE(get(Type, get_base_type(state.data.top().container.type)->value).elements)) { + state.data.pop(); + if (state.data.empty()) { + if (ingredient_index < SIZE(ingredients)) + raise << maybe(caller.name) << "too many ingredients in '" << to_original_string(inst) << "'\n" << end(); + return; + } + ++state.data.top().container_element_index; + } + } + // if not, maybe it's a field of the current element + else { + // no change to ingredient_index + state.data.push(merge_check_point(expected_ingredient, 0)); + } + break; + } + // End check_merge_call Special-cases + default: { + if (!types_coercible(container, ingredients.at(ingredient_index))) { + raise << maybe(caller.name) << "incorrect type of ingredient " << ingredient_index << " in '" << to_original_string(inst) << "'\n" << end(); + raise << " (expected '" << debug_string(container) << "')\n" << end(); + raise << " (got '" << debug_string(ingredients.at(ingredient_index)) << "')\n" << end(); + return; + } + ++ingredient_index; + // ++state.data.top().container_element_index; // unnecessary, but wouldn't do any harm + do { + state.data.pop(); + if (state.data.empty()) { + if (ingredient_index < SIZE(ingredients)) + raise << maybe(caller.name) << "too many ingredients in '" << to_original_string(inst) << "'\n" << end(); + return; + } + ++state.data.top().container_element_index; + } while (state.data.top().container_element_index >= SIZE(get(Type, get_base_type(state.data.top().container.type)->value).elements)); + } + } + } + // never gets here + assert(false); +} + +//: replaced in a later layer +//: todo: find some clean way to take this call completely out of this layer +const type_tree* get_base_type(const type_tree* t) { + return t; +} + +:(scenario merge_check_product) +% Hide_errors = true; +def main [ + 1:num <- merge 3 +] ++error: main: 'merge' should yield a container in '1:num <- merge 3' + +:(before "End Includes") +#include <stack> +using std::stack; |