Fixing bugs and fully implementing string compare in predicates

Author: mkitzan

include/cexpr/string.hpp

@@ -120,6 +120,18 @@ namespace cexpr
             return i == N;
         }
 
+		template <typename OtherCharT>
+    	bool operator==(std::basic_string<OtherCharT> const& other) const
+        {
+            return other == string_;
+        }
+
+		template <typename OtherCharT>
+    	bool operator!=(std::basic_string<OtherCharT> const& other) const
+        {
+            return !(other == string_);
+        }
+
     private:
         CharT string_[N];
         std::size_t size_;
@@ -129,17 +141,15 @@ namespace cexpr
     string(const CharT[N]) -> string<CharT, N>;
 
     template <typename CharT, std::size_t N>
-    constexpr bool operator==(std::basic_string<CharT> const& str, string<CharT, N> const& cstr)
+    bool operator==(std::basic_string<CharT> const& str, string<CharT, N> const& cstr)
     {
-        if (str.size() != N)
-        {
-            return false;
-        }
-
-        std::size_t i{};
-        for (; i < N && str[i] == cstr[i]; ++i);
+        return cstr == str;
+    }
 
-        return i == N;
+	template <typename CharT, std::size_t N>
+    bool operator!=(std::basic_string<CharT> const& str, string<CharT, N> const& cstr)
+    {
+        return cstr != str;
     }
 
 } // namespace cexpr

include/ra/selection.hpp

@@ -14,7 +14,7 @@ namespace ra
 
 		static auto& next()
 		{
-			auto& output_row = Input::next();
+			output_row = Input::next();
 
 			while(!Predicate::eval(output_row))
 			{
@@ -23,6 +23,12 @@ namespace ra
 
 			return output_row;
 		}
+
+	private:
+		static output_type output_row;
 	};
 
+	template <typename Output, typename Input>
+	typename selection<Output, Input>::output_type selection<Output, Input>::output_row{};
+
 } // namespace ra

include/sql/predicate.hpp

@@ -13,12 +13,12 @@ namespace sql
 		// shim to allow all value types like double or float
 		//	to be used as non-type template parameters.
 		template <typename ValT>
-		struct number
+		struct value
 		{
-			constexpr number(ValT val) : value{ val }
+			constexpr value(ValT v) : val{ v }
 			{}
 
-			ValT value;
+			ValT val;
 		};
 
 	} // namespace
@@ -81,7 +81,7 @@ namespace sql
 	{
 		static constexpr auto eval(Row const& row)
 		{
-			return Const.value;
+			return Const.val;
 		}
 	};
 

include/sql/query.hpp

@@ -61,7 +61,7 @@ namespace sql
 		}
 
 		template <typename ValT, typename CharT, std::size_t N>
-		constexpr number<ValT> convert(cexpr::string<CharT, N> const& str)
+		constexpr value<ValT> convert(cexpr::string<CharT, N> const& str)
 		{
 			auto curr{ str.cbegin() }, end{ str.cend() };
 			constexpr CharT nul{ '\0' }, dot{ '.' }, zro{ '0' }, min{ '-' };
@@ -91,7 +91,7 @@ namespace sql
 				}
 			}
 
-			return number<ValT>{ acc * sign };
+			return value<ValT>{ acc * sign };
 		}
 
 		constexpr bool isintegral(std::string_view const& tv) noexcept
@@ -192,7 +192,7 @@ namespace sql
 				constexpr auto pos{ Pos + 1 % tokens_.count() };
 				constexpr cexpr::string<char, tokens_[pos].length() + 1> name{ tokens_[pos] };
 
-				return TreeNode<Pos + 3, sql::constant<name, Row>>{};
+				return TreeNode<Pos + 3, sql::constant<value<decltype(name)>{ name }, Row>>{};
 			}
 			else if constexpr (isdigit(tokens_[Pos][0]))
 			{
@@ -224,7 +224,7 @@ namespace sql
 				constexpr cexpr::string<char, tokens_[pos].length() + 1> name{ tokens_[pos] };
 				constexpr auto node{ sql::operation<name, Row, typename Left::node, typename decltype(right)::node>{} };
 
-				return TreeNode<right.pos, decltype(node)>{};
+				return TreeNode<right.pos, std::remove_cvref_t<decltype(node)>>{};
 			}			
 		}
 
@@ -270,7 +270,7 @@ namespace sql
 				constexpr cexpr::string<char, tokens_[pos].length() + 1> name{ tokens_[pos] };
 				constexpr auto node{ sql::operation<name, Row, typename Left::node, typename decltype(right)::node>{} };
 
-				return recurse_logical<TreeNode<right.pos, decltype(node)>, Row>();
+				return recurse_logical<TreeNode<right.pos, std::remove_cvref_t<decltype(node)>>, Row>();
 			}
 		}
 
@@ -342,7 +342,7 @@ namespace sql
 
 			if constexpr (root.pos + 1 < tokens_.count() && (tokens_[root.pos] == "where" || tokens_[root.pos] == "WHERE"))
 			{
-				constexpr auto predicate{ parse_logical<root.pos + 1, typename decltype(root)::node::output_type>() };
+				constexpr auto predicate{ parse_logical<root.pos + 1, std::remove_cvref_t<typename decltype(root)::node::output_type>>() };
 
 				return ra::selection<typename decltype(predicate)::node, typename decltype(root)::node>{};
 			}

include/sql/tokens.hpp

@@ -77,7 +77,21 @@ namespace sql
 				last = curr;
 				last = next(last, end);
 
-				tokens_[i++] = token_view{ curr, (std::size_t) last - (std::size_t) curr };
+				if (*curr == '\"' || *curr == '\'')
+				{
+					tokens_[i++] = token_view{ curr, 1 };
+					for (char c{ *curr++ }; last != end && *last != c; ++last);
+				}
+
+				auto len{ reinterpret_cast<std::size_t>(last) - reinterpret_cast<std::size_t>(curr) };
+				tokens_[i++] = token_view{ curr, len };
+
+				if (*last == '\"' || *last == '\'')
+				{
+					tokens_[i++] = token_view{ last, 1 };
+					++last;
+				}
+
 				curr = last;
 			}
 		}

resources/tests/compose.py

@@ -36,6 +36,10 @@ def data(tokens):
 	return cs, ts
 
 def templ(query, ts):
+	num = 0
+	for t in ts:
+		query = query.replace(t, "T" + str(num))
+		num += 1
 	templ_spec = "\t\t\"" + query + "\""
 	for t in ts:
 		templ_spec += ",\n\t\t" + t

resources/tests/runner.py

@@ -18,6 +18,9 @@ def main():
 			for line in stream:
 				res = "Failed"
 			print("Test " + str(num) + ":\t" + res + "\n\t" + query)
+			if res == "Failed":
+				exit()
+			num += 1
 
 if __name__ == "__main__":
 	main()

resources/tests/test.cpp

@@ -0,0 +1,22 @@
+#include <iostream>
+
+#include "data.hpp"
+#include "sql/query.hpp"
+
+using query =
+	sql::query<
+		"select genre, year, pages from T0 where genre != \"science fiction\" and NOT year > 1970 and not pages = 300",
+		books
+	>;
+
+int main()
+{
+	books t0{ sql::load<books, '\t'>(data_folder + books_data) };
+
+	for (query q{ t0 }; auto const& [c0, c1, c2] : q)
+	{
+		std::cout << c0 << '|' << c1 << '|' << c2 << '\n';
+	}
+
+	return 0;
+}