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#include <mbgl/style/expression/let.hpp>
#include <mbgl/style/conversion/get_json_type.hpp>
#include <mbgl/util/string.hpp>
namespace mbgl {
namespace style {
namespace expression {
EvaluationResult Let::evaluate(const EvaluationContext& params) const {
return result->evaluate(params);
}
void Let::eachChild(const std::function<void(const Expression&)>& visit) const {
for (auto it = bindings.begin(); it != bindings.end(); it++) {
visit(*it->second);
}
visit(*result);
}
using namespace mbgl::style::conversion;
ParseResult Let::parse(const Convertible& value, ParsingContext& ctx) {
assert(isArray(value));
std::size_t length = arrayLength(value);
if (length < 4) {
ctx.error("Expected at least 3 arguments, but found " + util::toString(length - 1) + " instead.");
return ParseResult();
}
std::map<std::string, std::shared_ptr<Expression>> bindings_;
for(std::size_t i = 1; i < length - 1; i += 2) {
optional<std::string> name = toString(arrayMember(value, i));
if (!name) {
ctx.error("Expected string, but found " + getJSONType(arrayMember(value, i)) + " instead.", i);
return ParseResult();
}
bool isValidName = std::all_of(name->begin(), name->end(), [](unsigned char c) {
return std::isalnum(c) || c == '_';
});
if (!isValidName) {
ctx.error("Variable names must contain only alphanumeric characters or '_'.", 1);
return ParseResult();
}
ParseResult bindingValue = ctx.parse(arrayMember(value, i + 1), i + 1);
if (!bindingValue) {
return ParseResult();
}
bindings_.emplace(*name, std::move(*bindingValue));
}
ParseResult result_ = ctx.parse(arrayMember(value, length - 1), length - 1, ctx.getExpected(), bindings_);
if (!result_) {
return ParseResult();
}
return ParseResult(std::make_unique<Let>(std::move(bindings_), std::move(*result_)));
}
EvaluationResult Var::evaluate(const EvaluationContext& params) const {
return value->evaluate(params);
}
void Var::eachChild(const std::function<void(const Expression&)>&) const {}
ParseResult Var::parse(const Convertible& value_, ParsingContext& ctx) {
assert(isArray(value_));
if (arrayLength(value_) != 2 || !toString(arrayMember(value_, 1))) {
ctx.error("'var' expression requires exactly one string literal argument.");
return ParseResult();
}
std::string name_ = *toString(arrayMember(value_, 1));
optional<std::shared_ptr<Expression>> bindingValue = ctx.getBinding(name_);
if (!bindingValue) {
ctx.error(R"(Unknown variable ")" + name_ + R"(". Make sure ")" +
name_ + R"(" has been bound in an enclosing "let" expression before using it.)", 1);
return ParseResult();
}
return ParseResult(std::make_unique<Var>(name_, std::move(*bindingValue)));
}
} // namespace expression
} // namespace style
} // namespace mbgl
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