Scanner: Cleanup. (#411)

include/bx/inline/scanner.inl

@@ -12,14 +12,14 @@ namespace bx
 	inline Scanner::Scanner(const StringView& _input)
 		: m_input(_input)
 		, m_tail(_input)
-		, m_line(0)
+		, m_line(1)
 	{
 	}
 
 	inline void Scanner::reset()
 	{
 		m_tail = m_input;
-		m_line = 0;
+		m_line = 1;
 	}
 
 	inline StringView Scanner::acceptAll()
@@ -43,7 +43,7 @@ namespace bx
 			return moveBy(1);
 		}
 
-		return StringView();
+		return getCursor();
 	}
 
 	inline StringView Scanner::accept(char _ch0, char _ch1)
@@ -59,7 +59,7 @@ namespace bx
 			}
 		}
 
-		return StringView();
+		return getCursor();
 	}
 
 	template<typename ...Args>
@@ -82,7 +82,7 @@ namespace bx
 			return moveTo({ m_tail.getPtr(), _str.getLength() });
 		}
 
-		return StringView();
+		return getCursor();
 	}
 
 	inline StringView Scanner::accept(Class _class)
@@ -98,7 +98,7 @@ namespace bx
 			return moveBy(1);
 		}
 
-		return StringView();
+		return getCursor();
 	}
 
 	inline StringView Scanner::acceptWhile(const StringView& _any)
@@ -110,7 +110,7 @@ namespace bx
 			return moveTo({ m_tail.getPtr(), input.getPtr() });
 		}
 
-		return StringView();
+		return getCursor();
 	}
 
 	inline StringView Scanner::acceptWhile(CharTestFn _fn)
@@ -136,7 +136,7 @@ namespace bx
 			return moveTo({ m_tail.getPtr(), result.getPtr() });
 		}
 
-		return result;
+		return getCursor();
 	}
 
 	inline StringView Scanner::acceptUntil(Class _class)
@@ -148,7 +148,7 @@ namespace bx
 	inline StringView Scanner::peek() const
 	{
 		return m_tail.isEmpty()
-			? StringView()
+			? getCursor()
 			: StringView(m_tail.getPtr(), m_tail.getPtr() + 1)
 			;
 	}
@@ -161,7 +161,7 @@ namespace bx
 			return StringView(m_tail.getPtr(), m_tail.getPtr() + 1);
 		}
 
-		return StringView();
+		return getCursor();
 	}
 
 	inline StringView Scanner::peek(const StringView& _str) const
@@ -171,7 +171,7 @@ namespace bx
 			return StringView(m_tail.getPtr(), _str.getLength() );
 		}
 
-		return StringView();
+		return getCursor();
 	}
 
 	inline StringView Scanner::peek(Class _class) const

include/bx/scanner.h

@@ -16,7 +16,9 @@ namespace bx
 	/// moves. `accept*` functions advance cursor when they match, `peek*` functions perform the
 	/// same test without moving cursor.
 	///
-	/// All returned string views point into input string, and no copies are made.
+	/// All returned string views point into input string, and no copies are made. This includes
+	/// empty string views returned when nothing matched, which point at cursor rather than being
+	/// default constructed. They can be used with `seek` and `between`.
 	///
 	/// @attention Scanner doesn't own input string. Input string must outlive Scanner.
 	///
@@ -142,11 +144,11 @@ namespace bx
 		///
 		/// @param[in] _find String to search for.
 		///
-		/// @returns Accepted string view, or empty string view if `_find` is not found, or it's
-		///   already at cursor.
+		/// @returns Accepted string view, or empty string view at cursor if `_find` is not found,
+		///   or it's already at cursor.
 		///
-		/// @attention Returned string view is empty in both cases, and cursor doesn't move.
-		///   Use `getCursor` and `between` to capture text that can legitimately be empty.
+		/// @attention Returned string view is empty in both cases, and cursor doesn't move. If
+		///   these two cases have to be told apart, test for `_find` separately with `peek`.
 		///
 		StringView acceptUntil(const StringView& _find);
 
@@ -208,7 +210,7 @@ namespace bx
 		///
 		bool seek(int32_t _bytes);
 
-		/// Returns zero-based line number cursor is on.
+		/// Returns one-based line number cursor is on.
 		///
 		/// @returns Line number.
 		///
@@ -226,9 +228,9 @@ namespace bx
 		///
 		/// @returns Zero length string view at requested position.
 		///
-		/// @remarks Unlike default constructed `StringView`, returned string view keeps pointer
-		///   into input string even though it's empty. Use it with `between` to capture text that
-		///   can legitimately be empty.
+		/// @remarks Returned string view keeps pointer into input string even though it's empty,
+		///   and it can be passed to `seek` to return to this position later, or to `between` to
+		///   capture text that can legitimately be empty.
 		///
 		StringView getCursor(Cursor _which = Cursor::Current) const;
 
@@ -250,10 +252,10 @@ namespace bx
 	private:
 		/// Move cursor to `_to`, and update line number.
 		///
-		/// @param[in] _to Position to move cursor to.
+		/// @param[in] _to Position to move cursor to. Empty string view is treated as cursor
+		///   position obtained by `getCursor` rather than as span, and cursor moves to it.
 		///
-		/// @returns String view between old and new cursor position, or empty string view if `_to`
-		///   is empty.
+		/// @returns String view between old and new cursor position.
 		///
 		StringView moveTo(const StringView& _to);
 

src/scanner.cpp

@@ -71,7 +71,13 @@ namespace bx
 			return result;
 		}
 
-		return StringView();
+		if (_to.getPtr() != m_tail.getPtr()
+		&&  contain(m_input, _to) )
+		{
+			moveBy(int32_t(_to.getPtr() - m_tail.getPtr() ) );
+		}
+
+		return getCursor();
 	}
 
 	StringView Scanner::strFunc(Class _class) const

src/url.cpp

@@ -51,9 +51,7 @@ namespace bx
 
 		Scanner scanner(_url);
 
-		const StringView schemeBegin = scanner.getCursor();
-		scanner.acceptUntil("://");
-		const StringView scheme = scanner.between(schemeBegin);
+		const StringView scheme = scanner.acceptUntil("://");
 
 		const bool hasScheme = !scanner.accept("://").isEmpty();
 
@@ -67,9 +65,7 @@ namespace bx
 			m_tokens[Scheme].set(scheme);
 		}
 
-		const StringView authorityBegin = scanner.getCursor();
-		scanner.acceptWhile(isNotSlash);
-		const StringView authority = scanner.between(authorityBegin);
+		const StringView authority = scanner.acceptWhile(isNotSlash);
 
 		const bool hasPath = !scanner.peek('/').isEmpty();
 
@@ -81,22 +77,16 @@ namespace bx
 
 		if (hasPath)
 		{
-			const StringView pathBegin = scanner.getCursor();
-			scanner.acceptWhile(isNotQueryOrFragment);
-			m_tokens[Path].set(scanner.between(pathBegin) );
+			m_tokens[Path].set(scanner.acceptWhile(isNotQueryOrFragment) );
 
 			if (!scanner.accept('?').isEmpty() )
 			{
-				const StringView queryBegin = scanner.getCursor();
-				scanner.acceptWhile(isNotFragment);
-				m_tokens[Query].set(scanner.between(queryBegin) );
+				m_tokens[Query].set(scanner.acceptWhile(isNotFragment) );
 			}
 
 			if (!scanner.accept('#').isEmpty() )
 			{
-				const StringView fragmentBegin = scanner.getCursor();
-				scanner.acceptWhile(isNotQuery);
-				m_tokens[Fragment].set(scanner.between(fragmentBegin) );
+				m_tokens[Fragment].set(scanner.acceptWhile(isNotQuery) );
 			}
 
 			// Anything left over is a query following a fragment.
@@ -108,17 +98,13 @@ namespace bx
 
 		Scanner authorityScanner(authority);
 
-		const StringView userInfoBegin = authorityScanner.getCursor();
-		authorityScanner.acceptUntil("@");
-		const StringView userInfo = authorityScanner.between(userInfoBegin);
+		const StringView userInfo = authorityScanner.acceptUntil("@");
 
 		if (!authorityScanner.accept('@').isEmpty() )
 		{
 			Scanner userInfoScanner(userInfo);
 
-			const StringView userNameBegin = userInfoScanner.getCursor();
-			userInfoScanner.acceptWhile(isNotColon);
-			m_tokens[UserName].set(userInfoScanner.between(userNameBegin) );
+			m_tokens[UserName].set(userInfoScanner.acceptWhile(isNotColon) );
 
 			if (!userInfoScanner.accept(':').isEmpty() )
 			{
@@ -126,9 +112,7 @@ namespace bx
 			}
 		}
 
-		const StringView hostBegin = authorityScanner.getCursor();
-		authorityScanner.acceptWhile(isNotColon);
-		m_tokens[Host].set(authorityScanner.between(hostBegin) );
+		m_tokens[Host].set(authorityScanner.acceptWhile(isNotColon) );
 
 		if (!authorityScanner.accept(':').isEmpty() )
 		{

tests/scanner_test.cpp

@@ -14,7 +14,7 @@ namespace bx
 		Scanner scanner(_str);
 		scanner.acceptAll();
 
-		return scanner.getLine();
+		return scanner.getLine() - 1;
 	}
 
 	void printLines(const StringView& _str)
@@ -79,27 +79,27 @@ TEST_CASE("Scanner", "[scanner]")
 	REQUIRE(!scanner.isDone() );
 	REQUIRE("xyz" == scanner.accept("xyz") );
 
-	REQUIRE(0 == scanner.getLine() );
-	REQUIRE("\n    " == scanner.acceptUntil(bx::Scanner::Class::Space) );
 	REQUIRE(1 == scanner.getLine() );
+	REQUIRE("\n    " == scanner.acceptUntil(bx::Scanner::Class::Space) );
+	REQUIRE(2 == scanner.getLine() );
 
 	scanner.acceptAll();
 	REQUIRE(scanner.accept().isEmpty() );
 
-	REQUIRE(numLines == scanner.getLine() );
+	REQUIRE(numLines + 1 == scanner.getLine() );
 
 	REQUIRE(scanner.isDone() );
 
 	REQUIRE(scanner.seek(start) );
-	REQUIRE(0 == scanner.getLine() );
+	REQUIRE(1 == scanner.getLine() );
 	REQUIRE(!scanner.isDone() );
 
 	REQUIRE(scanner.seek(INT32_MAX) );
-	REQUIRE(numLines == scanner.getLine() );
+	REQUIRE(numLines + 1 == scanner.getLine() );
 	REQUIRE(scanner.isDone() );
 
 	REQUIRE(scanner.seek(INT32_MIN) );
-	REQUIRE(0 == scanner.getLine() );
+	REQUIRE(1 == scanner.getLine() );
 	REQUIRE(!scanner.isDone() );
 }
 
@@ -206,7 +206,7 @@ TEST_CASE("Scanner.getColumn", "[scanner]")
 	REQUIRE(4 == sc.getColumn() );
 
 	sc.accept('\n');
-	REQUIRE(1 == sc.getLine() );
+	REQUIRE(2 == sc.getLine() );
 	REQUIRE(1 == sc.getColumn() );
 	sc.accept();
 	REQUIRE(2 == sc.getColumn() );
@@ -237,11 +237,11 @@ TEST_CASE("Scanner.reset", "[scanner]")
 
 	sc.acceptAll();
 	REQUIRE(sc.isDone() );
-	REQUIRE(2 == sc.getLine() );
+	REQUIRE(3 == sc.getLine() );
 
 	sc.reset();
 	REQUIRE(!sc.isDone() );
-	REQUIRE(0 == sc.getLine() );
+	REQUIRE(1 == sc.getLine() );
 	REQUIRE(1 == sc.getColumn() );
 	REQUIRE("abc" == sc.accept(bx::Scanner::Class::Identifier) );