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POEdit a list in a given position?
 

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    <p>And it goes like this. Someone have a chain of restaurants. each restaurant is a 3-tuple with a “restaurant name”, an number of tables and a 3-tuple list with the menu (price, "recipe name" , "special ingredient") :</p> <pre><code>("restaurant name", number of tables, [(price, "recipe name" , "special ingredient")]) </code></pre> <p>So, I got something like:</p> <pre><code>chainRestaurants = [("Food and friends",20,[(2.5,"Steak","lemon"),(3.5,"Vegetarian Meals","tomato"),(4.0,"Italian Beef","banana")]),("All in",10,[(2.5,"Stracotto","Garlic"),(3.0,"Roast Beef","Butter"),(3.3,"Veal Chops","Pepper")]),("Orange",25,[(4.5,"Turkey","Mustard"),(5.1,"Chicken","egg"),(6.0,"Chicken Salad","fruit")])] </code></pre> <p>Part of my assignment (the part where I’m stuck in) is: pick the restaurantlist and add, replace, change the order, edit the menus, the restaurants and the restaurant chain list.</p> <p>So, the Question: make a function that allows to edit a 3-tuple (a recipe) from a menu, given the restaurant name position, the menu position and the new recipe.</p> <p>example: editRecipe 1 2 (2222,"SSSSSS","llllll")</p> <p>output:</p> <pre><code>[("Food and friends",20,[(2.5,"Steak","lemon"),(2222,"SSSSSS","llllll"),(4.0,"Italian Beef","banana")]),("All in",10,[(2.5,"Stracotto","Garlic"),(3.0,"Roast Beef","Butter"),(3.3,"Veal Chops","Pepper")]),("Orange",25,[(4.5,"Turkey","Mustard"),(5.1,"Chicken","egg"),(6.0,"Chicken Salad","fruit")])] </code></pre> <p>I've already solve this problem, but never with a 3-tuple as an argument... and I need it! :/</p> <p>There's my code:</p> <pre><code>chainRestaurants = [("Food and friends",20,[(2.5,"Steak","lemon"),(3.5,"Vegetarian Meals","tomato"),(4.0,"Italian Beef","banana")]),("All in",10,[(2.5,"Stracotto","Garlic"),(3.0,"Roast Beef","Butter"),(3.3,"Veal Chops","Pepper")]),("Orange",25,[(4.5,"Turkey","Mustard"),(5.1,"Chicken","egg"),(6.0,"Chicken Salad","fruit")])] menu1 = [(2.5,"Steak","lemon"),(3.5,"Vegetarian Meals","tomato"),(4.0,"Italian Beef","banana")] restaurant1 = ("Food and friends",20,menu1) menu2 = [(2.5,"Stracotto","Garlic"),(3.0,"Roast Beef","Butter"),(3.3,"Veal Chops","Pepper")] restaurant2 = ("All in",10,menu2) menu3 = [(4.5,"Turkey","Mustard"),(5.1,"Chicken","egg"),(6.0,"Chicken Salad","fruit")] restaurant3 = ("Orange",25,menu3) chainRestaurants1 = [restaurant1] ++ [restaurant2] ++ [restaurant3] editRecipe restaurantposition menuposition newrecipe | menuposition == 0 = error "No such thing" | restaurantposition == 1 &amp;&amp; menuposition &gt; length menu1 = error "No such thing" | restaurantposition == 2 &amp;&amp; menuposition &gt; length menu2 = error "No such thing" | restaurantposition == 3 &amp;&amp; menuposition &gt; length menu3 = error "No such thing" editRecipe restaurantposition menuposition newrecipe = case restaurantposition of 1 -&gt; [("Food and friends",20, take (menuposition-1) menu1 ++ newrecipe ++ drop (menuposition) menu1)] ++ [restaurant2] ++ [restaurant3] 2 -&gt; [restaurant1] ++ [("Food and friends",20, take (menuposition-1) menu2 ++ newrecipe ++ drop (menuposition) menu2)] ++ [restaurant3] 3 -&gt; [restaurant1] ++ [restaurant2] ++ [("Orange",25, take (menuposition-1) menu3 ++ newrecipe ++ drop (menuposition) menu3)] otherwise -&gt; error "No such thing" </code></pre> <p>But this code need a list (newrecipe) as argument, but I need a 3-tuple. :/</p> <pre><code>ex: editRecipe 1 2 [(5.1,"xxxxxxxxx","ccccccccccc")] </code></pre> <p>and I need:</p> <pre><code>editRecipe 1 2 (5.1,"xxxxxxxxx","ccccccccccc") </code></pre> <p>But with my code, I must insert a list whit a tuple as argument. The question is: is it possible to insert only a tuple as argument and not a list?</p>
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    1. COIt doesn't matter if that argument is a 3-tuple or any other kind of value... It should work the same way as where you solved this problem before.
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    2. COThe SO community responds much better if you provide your code that failed, even if it doesn't compile. Allowing us to give advice and point out easier methods.
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      1. USThomas M. DuBuisson
    3. COThis question is vague. What exactly do you want your function(s) to do?
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      1. USPrateek
 

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