answer:In your code, your `options_for_select()` call sets the selected value to "gender" and does not attempt to use the value from your form object. Please see the docs for options_for_select()(http://api.rubyonrails.org/classes/ActionView/Helpers/FormOptionsHelper.html#method-i-options_for_select) for usage examples. ```ruby options_for_select('Mare', 'Stallion', 'Gelding', f.object.gender) options_for_select('Mare', 'Stallion', 'Gelding', :selected => f.object.gender) ``` Alternatively, you can do this(http://api.rubyonrails.org/classes/ActionView/Helpers/FormOptionsHelper.html#method-i-select), which will already use the `gender()` value for your form object: ```ruby <%= f.select :gender, 'Mare', 'Stallion', 'Gelding' %> ```,It's difficult to provide a specific answer without knowing more details about your code. However, I can provide a general overview of how to select the correct option in a select form in erb. Here are the steps you can follow: 1. First, you need to get the value from the action that was sent to the form. 2. Then, you join a loop in erb that includes all the possible options, so each option has its own line. 3. Check if the option's value matches the selected value. If it matches, add a selected attribute to the respective option, like this: ``` <% @page_contents.each do |feed| %> <option <%= 'selected' if feed.visibility == 'private' %> value='<%= feed.visibility %>' > <%= feed.visibility %> </option> <% end %> ``` If you are not familiar with any of these steps, I suggest you do some research on erb and its syntax., It sounds like you may be having an issue with pre-selecting the correct option in a form select field in your ERB template. Here are a few things you can check: 1. Make sure you are setting the `value` attribute of the `<option>` element to the correct value for the current record. This should match the value of the corresponding attribute in the object you are editing. 2. Ensure that the `name` attribute of the `<select>` element matches the name of the attribute you are editing in your object. 3. Check that the object you are editing is not `nil`. If it is, then the form helpers won't be able to set the selected value correctly. 4. Make sure that you are passing the correct object to the form partial or include. 5. If you are using a collection of options (e.g., `collection_select`), ensure that the `value` option in the helper method matches the value of the current record's attribute. 6. Ensure that you have included the `form_for` or `form_with` helper at the beginning of your ERB file to define the form context. If you're still having trouble, you can post your ERB code and any relevant controller code, and I can take a closer look to help you further.

answer:As the error message says: ``` expected type `&mut _` found type `&closure@src/main.rs:3:25: 3:53 string:_` ``` It is expecting a mutable reference to something (`&mut _`), but you are providing an immutable reference to a closure (`&...`). To solve this, you need to take a mutable reference: ```rust call(&mut change_string); ``` However, this will result in another error: ``` error: cannot borrow immutable local variable `change_string` as mutable --> src/main.rs:9:15 | 3 | let change_string = || string.push_str(" world"); | ------------- use `mut change_string` here to make mutable ... 9 | call(&mut change_string); | ^^^^^^^^^^^^^ cannot borrow mutably ``` Taking a mutable reference requires that the value itself be mutable. To fix this, you need to declare `change_string` as mutable: ```rust let mut change_string = || string.push_str(" world"); ``` In this case, you don't need to take a `&mut F` at all, as `FnMut` is implemented for mutable references to `FnMut`. So, you can simplify the code like this: ```rust fn call(mut f: impl FnMut()) { f(); } call(&mut change_string); call(&mut change_string); ``` This will allow you to call the `change_string` closure mutably without any errors.,The error occurs because you are trying to pass a closure by value (`&change_string`) with a mutable reference when the function signature requires a mutable reference (`&mut F`). To solve this issue, you need to pass the closure by value explicitly: ```rust let mut string: String = "hello".to_owned(); let change_string = || string.push_str(" world"); fn call<F>(mut f: &mut F) where F: FnMut(), { f(); } call(change_string); // You need to pass the closure by value call(change_string); ``` By using `call(change_string)`, you are passing the closure directly instead of the reference to it. This should resolve the type mismatch error and allow you to call the closure multiple times., The issue here is that you're trying to pass a mutable reference to a closure that is not defined as mutable. Even though you're using `FnMut`, the closure itself does not need to be mutable because it does not capture any mutable variables. To fix this, you need to define `change_string` as a mutable closure: ```rust let mut string: String = "hello".to_owned(); let mut change_string = || { string.push_str(" world"); }; fn call<F>(mut f: &mut F) where F: FnMut(), { f(); } call(&mut change_string); call(&mut change_string); ``` Now, the closure `change_string` is defined as mutable, and you can pass a mutable reference to it when calling `call`. The `call` function also takes a mutable reference to `F` to match the argument type.

answer:Learning about PowerPC architecture and programming can be challenging when it comes to finding affordable evaluation boards and platforms. However, there are a few options and resources available for you to explore: 1. Personal Computer/laptops: Many modern personal computers and laptops run on processors that are based on the PowerPC architecture. You can leverage this fact to explore PowerPC assembly programming through the use of emulators or virtual environments. Some operating systems compatible with PowerPC include Linux/BSD distributions, such as Gentoo Linux or NetBSD. 2. Freescale Semiconductor's development boards: Freescale (now part of NXP) has offered several PowerPC-based evaluation boards in the past. However, many of these boards might not be available at a lower cost nowadays. Nonetheless, you can try checking out the second-hand market or local suppliers to see if any affordable options can be found. 3. Online communities and resources: There are various open-source projects and online communities that develop and support PowerPC systems. Engaging with these communities can provide you with additional resources, tutorials, and assistance with any questions or challenges you might encounter. Some popular platforms in this category include PowerPC Linux communities. 4. Books and learning resources: Although you mentioned that you already have a strong background in assembly and compiler technology, for anyone interested in learning PowerPC assembly programming, consider these highly recommended books: - "PowerPC System Architecture" by James Brown, Brian H. Evans, Robert E. Hilliard, and Bill Harris - "PowerPC Assembly Language" by William Dally and Michael Lam - "PowerPC Microprocessor Family: Programming, Interfacing, Troubleshooting" by John Iovino, John W. Valvano, and Frank Vahid Remember, building solid knowledge and practice in embedded systems involves investing time and resources. Be patient, explore different avenues, and continue learning from the resources available to you.,A cost-effective way to learn about PowerPC architecture is to get an old PowerPC Mac. You can find various models, ranging from old System 7 machines to the ones sold until they stopped producing PowerPC Macs. These older Macs can serve as a platform for you to practice programming in PowerPC assembly and gain a deeper understanding of the architecture. You can search online marketplaces or auction websites to find affordable options. Here are a couple of links to get you started: - G3 Macs(http://www.google.com/products?q=g3+mac&hl=en&aq=f) - Original iMac(http://www.google.com/products?q=original+imac&hl=en&aq=f) By acquiring one of these machines, you can experiment with PowerPC assembly programming and gain hands-on experience. As for books on PowerPC architecture and programming, here are a few recommendations: 1. "PowerPC System Architecture" by Steve Hoxey - This book provides a comprehensive overview of the PowerPC system architecture, covering topics such as instruction set, memory management, and input/output. 2. "PowerPC Microprocessor Common Hardware Reference Platform" by IBM - This reference manual from IBM dives deep into the technical details of the PowerPC microprocessor, including its architecture, instruction set, and system design. 3. "Embedded Systems Programming on PowerPC" by Ray Weiss - This book focuses specifically on embedded systems programming using PowerPC architecture. It covers topics such as real-time operating systems, device drivers, and system integration. These books will help you gain a solid understanding of PowerPC architecture and enable you to apply your knowledge effectively in embedded systems development., While PowerPC evaluation boards can be expensive, there are a few options that might be more budget-friendly for you to learn about PowerPC architecture and programming. 1. Single-board computers (SBCs) with PowerPC processors: One more affordable option is to look for single-board computers (SBCs) with PowerPC processors. The prices are generally lower than evaluation boards, and you can still practice programming and working with the PowerPC architecture. One example is the Genesi Efika Smartbook, which has a PowerPC processor and can be found used for around 100-200. Another option is the TQMa6x series of SBCs from Toradex, which have PowerPC processors starting at around 250. 2. Emulation and virtualization: Using emulators or virtual machines can be a cost-effective way to learn PowerPC assembly programming. You can set up a virtual PowerPC environment on your current computer and practice coding without needing dedicated hardware. One popular choice is QEMU, a free and open-source emulator that supports PowerPC architectures. 3. Raspberry Pi: The Raspberry Pi doesn't use a PowerPC architecture, but it can still be a helpful platform for learning assembly programming with an ARM-based architecture. The knowledge and experience you gain can be applied to PowerPC programming, as both ARM and PowerPC are RISC architectures. For learning PowerPC assembly and architecture, the following books are highly recommended: 1. "Programming and Interfacing the PowerPC" by K.K. Mehrotra: This book provides a comprehensive introduction to PowerPC architecture, assembly programming, and interfacing with peripherals. 2. "PowerPC Assembly Language Programming: For the Cell Broadband Engine Architecture" by Suzanne Matthews and Kenneth I. Kozyrkov: Although this book focuses on the Cell Broadband Engine architecture, it can still provide valuable insights into PowerPC assembly programming. 3. "The PowerPC Companion" by Rick Booth and Jim Wilson: This book provides an easy-to-understand introduction to PowerPC architecture and assembly programming. 4. "The PowerPC Microprocessor Family: Architecture and Interfacing" by Mohammad Tehranipoor and Reza Curtmola: This book offers a thorough analysis of PowerPC architecture and its interface, making it an excellent resource for understanding the inner workings of PowerPC processors.

answer:To resolve this issue, you need to make two changes. Firstly, you are calling the form_search function on the model from the controller, so you should use the following code: ```ruby Project.form_search ``` Additionally, you need to define the form_search method in the model as a class method using: ```ruby def self.form_search ``` Secondly, you are trying to access the params variable within the model, but in the MVC architecture, the model is unaware of the request, so the params variable is not defined there. To fix this, you should pass the variable as a parameter to your function, as you are already doing. Your updated code in the model should look like this: ```ruby def self.form_search(searches) searches = searches.where('amount > ?', params:price_min) if check_params(params:price_min) @project_pages = ProjectPage.where(:project_id => searches.pluck(:'projects.id')) end ``` By making these changes, you should be able to successfully call the form_search method from your ProjectPage controller.,It seems like you're trying to call the form_search method from the ProjectPage controller, but the method is actually defined in the ProjectPage model. In Rails, it's not common to call methods defined in the model from the controller. Instead, you should pass the searches parameter as an instance variable in the controller and use it in the model. Here's an alternative approach you can try: 1. Modify your ProjectPage controller's index method to pass the necessary parameters to the model: ```ruby def index @searches = Project.published.financed @project_pages = form_search(@searches, params) end ``` 2. Define the form_search method in the ProjectPage model, taking the searches and parameters as arguments: ```ruby def self.form_search(searches, params) searches = searches.where('amount > ?', params:price_min) if check_params(params:price_min) @project_pages = ProjectPage.where(:project_id => searches.pluck(:'projects.id')) end ``` By refactoring your code like this, the form_search method will be called correctly and you should be able to retrieve the required data from the model., It looks like you're trying to call the `form_search` method from your `ProjectPage` model, but it's currently defined as an instance method. That means you would need to call it on an instance of the `ProjectPage` model, like this: ```ruby @project_page = ProjectPage.new @project_pages = @project_page.form_search(params) ``` However, it seems like you actually want to define `form_search` as a class method, since you're calling it in the `index` action of your `ProjectPage` controller. Here's how you can define it as a class method: In your `ProjectPage` model: ```ruby def self.form_search(searches) searches = searches.where('amount > ?', params:price_min) if check_params(params:price_min) ProjectPage.where(:project_id => searches.pluck(:'projects.id')) end ``` Then in your `ProjectPage` controller: ```ruby def index @searches = Project.published.financed @project_pages = ProjectPage.form_search(@searches) end ``` Note that I changed the method definition to use `self`, which makes it a class method. I also updated the argument to `form_search` to be `@searches` instead of `params` since that's the variable you're passing in from the controller. With these changes, `form_search` should now be successfully called in your controller.