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#include <mbgl/style/expression/case.hpp>
#include <mbgl/util/string.hpp>
namespace mbgl {
namespace style {
namespace expression {
EvaluationResult Case::evaluate(const EvaluationContext& params) const {
for (const auto& branch : branches) {
const EvaluationResult evaluatedTest = branch.first->evaluate(params);
if (!evaluatedTest) {
return evaluatedTest.error();
}
if (evaluatedTest->get<bool>()) {
return branch.second->evaluate(params);
}
}
return otherwise->evaluate(params);
}
void Case::eachChild(const std::function<void(const Expression&)>& visit) const {
for (const Branch& branch : branches) {
visit(*branch.first);
visit(*branch.second);
}
visit(*otherwise);
}
bool Case::operator==(const Expression& e) const {
if (auto rhs = dynamic_cast<const Case*>(&e)) {
return *otherwise == *(rhs->otherwise) && Expression::childrenEqual(branches, rhs->branches);
}
return false;
}
std::vector<optional<Value>> Case::possibleOutputs() const {
std::vector<optional<Value>> result;
for (const auto& branch : branches) {
for (auto& output : branch.second->possibleOutputs()) {
result.push_back(std::move(output));
}
}
for (auto& output : otherwise->possibleOutputs()) {
result.push_back(std::move(output));
}
return result;
}
using namespace mbgl::style::conversion;
ParseResult Case::parse(const Convertible& value, ParsingContext& ctx) {
assert(isArray(value));
auto length = arrayLength(value);
if (length < 4) {
ctx.error("Expected at least 3 arguments, but found only " + util::toString(length - 1) + ".");
return ParseResult();
}
// Expect even-length array: ["case", 2 * (n pairs)..., otherwise]
if (length % 2 != 0) {
ctx.error("Expected an odd number of arguments");
return ParseResult();
}
optional<type::Type> outputType;
if (ctx.getExpected() && *ctx.getExpected() != type::Value) {
outputType = ctx.getExpected();
}
std::vector<Case::Branch> branches;
branches.reserve((length - 2) / 2);
for (size_t i = 1; i + 1 < length; i += 2) {
auto test = ctx.parse(arrayMember(value, i), i, {type::Boolean});
if (!test) {
return test;
}
auto output = ctx.parse(arrayMember(value, i + 1), i + 1, outputType);
if (!output) {
return output;
}
if (!outputType) {
outputType = (*output)->getType();
}
branches.push_back(std::make_pair(std::move(*test), std::move(*output)));
}
assert(outputType);
auto otherwise = ctx.parse(arrayMember(value, length - 1), length - 1, outputType);
if (!otherwise) {
return otherwise;
}
return ParseResult(std::make_unique<Case>(*outputType,
std::move(branches),
std::move(*otherwise)));
}
} // namespace expression
} // namespace style
} // namespace mbgl
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