Method Invoke

source/TextIO.cpp:810–1029

	}

	ResultType Invoke(ResultToken &aResultToken, int aID, int aFlags, ExprTokenType *aParam[], int aParamCount)
	{
		aResultToken.symbol = SYM_INTEGER; // Set default return type -- the most common cases return integer.

		auto member = MemberID(aID);
		switch (member)
		{
		case M_Read:
			{
				DWORD length;
				if (aParamCount)
					length = (DWORD)ParamIndexToInt64(0);
				else
					length = (DWORD)(mFile.Length() - mFile.Tell()); // We don't know the actual number of characters these bytes will translate to, but this should be sufficient.
				if (length == -1)
					break; // Fail.
				if (!TokenSetResult(aResultToken, NULL, length)) // Only after checking length above: TokenSetResult requires non-NULL aResult if aResultLength == -1.
					return FAIL;
				length = mFile.Read(aResultToken.marker, length);
				aResultToken.symbol = SYM_STRING;
				aResultToken.marker[length] = '\0';
				aResultToken.marker_length = length; // Update marker_length to the actual number of characters read.
				return OK;
			}
			break;
		
		case M_ReadLine:
			{	// See above for comments.
				if (!TokenSetResult(aResultToken, NULL, READ_FILE_LINE_SIZE))
					return FAIL;
				DWORD length = mFile.ReadLine(aResultToken.marker, READ_FILE_LINE_SIZE - 1);
				aResultToken.symbol = SYM_STRING;
				if (length && aResultToken.marker[length - 1] == '\n')
					--length;
				aResultToken.marker[length] = '\0';
				aResultToken.marker_length = length;
				return OK;
			}
			break;

		case M_Write:
		case M_WriteLine:
			{
				DWORD bytes_written = 0;
				size_t chars_to_write = 0;
				if (aParamCount)
				{
					LPTSTR param1 = ParamIndexToString(0, _f_number_buf, &chars_to_write);
					bytes_written = mFile.Write(param1, (DWORD)chars_to_write);
				}
				if (member == M_WriteLine && (bytes_written || !chars_to_write)) // i.e. don't attempt it if above failed.
				{
					bytes_written += mFile.Write(_T("\n"), 1);
				}
				aResultToken.value_int64 = bytes_written;
				return OK;
			}
			break;