I have strings and determine the ranges of indexes. I will need later for instance .last .count for these ranges. How should I initialise the range for string to be able to get functionality .last .count for these ranges (that is obvious in swift2 but not in swift3) ?
For example, I am often using the .count for range of string in my code in swift2, like this
var str = "Hello, playground"
let myRange = str.rangeOfString("Hello")
let myCountOfRange = myRange.count
Now it is not possible to do this in swift3
var str = "Hello, playground"
let myRange = str.range(of: "Hello")
let myCountOfRange = myRange.count // type index does not conform to protocol strideable
In Swift3, to find the size of a range you can do:
var str = "Hello, playground"
let myRange = str.range(of: "Hello")
let myCountOfRange = str[myRange!].characters.count
I don't know if this is the best way, but it works.
Alternatively:
let myCountOfRange = str.distance(from: myRange!.lowerBound, to: myRange!.upperBound)
Both require access to the original collection (ie. string), and that apparently is a limitation of Swift 3. The new model for collections and indices is discussed here.
If you want to store the ranges in an array and call .count and .last on them, you can convert the Range<Index> to a CountableRange<Int> while you still have access to the collection:
var str = "Hello, playground"
let myRange = str.range(of: "Hello")!
let lb = str.distance(from: str.startIndex, to: myRange.lowerBound) as Int
let ub = str.distance(from: str.startIndex, to: myRange.upperBound) as Int
let newRange = lb..<ub
newRange.count // 5
newRange.last // 4
Related
I have a range of data in a Google Sheet and I want to store that data into an array using the app script. At the moment I can bring in the data easily enough and put it into an array with this code:
var sheetData = sheet.getSheetByName('Fruit').getRange('A1:C2').getValues()
However, this puts each row into an array. For example, [[Apple,Red,Round],[Banana,Yellow,Long]].
How can I arrange the array by columns so it would look: [[Apple,Banana],[Red,Yellow],[Round,Long]].
Thanks.
It looks like you have to transpose the array. You can create a function
function transpose(data) {
return (data[0] || []).map (function (col , colIndex) {
return data.map (function (row) {
return row[colIndex];
});
});
}
and then pass the values obtained by .getValues() to that function..
var sheetData = transpose(sheet.getSheetByName('Fruit').getRange('A1:C2').getValues())
and check the log. See if that works for you?
Use the Google Sheets API, which allows you to specify the primary dimension of the response. To do so, first you must enable the API and the advanced service
To acquire values most efficiently, use the spreadsheets.values endpoints, either get or batchGet as appropriate. You are able to supply optional arguments to both calls, and one of which controls the orientation of the response:
const wb = SpreadsheetApp.getActive();
const valService = Sheets.Spreadsheets.Values;
const asColumn2D = { majorDimension: SpreadsheetApp.Dimension.COLUMNS };
const asRow2D = { majorDimension: SpreadsheetApp.Dimension.ROWS }; // this is the default
var sheet = wb.getSheetByName("some name");
var rgPrefix = "'" + sheet.getName() + "'!";
// spreadsheetId, range string, {optional arguments}
var single = valService.get(wb.getId(), rgPrefix + "A1:C30");
var singleAsCols = valService.get(wb.getId(), rgPrefix + "A1:C30", asColumn2D);
// spreadsheetId, {other arguments}
var batchAsCols = valService.batchGet(wb.getId(), {
ranges: [
rgPrefix + "A1:C30",
rgPrefix + "J8",
...
],
majorDimension: SpreadsheetApp.Dimension.COLUMNS
});
console.log({rowResp: single, colResp: singleAsCols, batchResponse: batchAsCols});
The reply will either be a ValueRange (using get) or an object wrapping several ValueRanges (if using batchGet). You can access the data (if any was present) at the ValueRange's values property. Note that trailing blanks are omitted.
You can find more information in the Sheets API documentation, and other relevant Stack Overflow questions such as this one.
I started with Metalkit and I have a very simple kernel as a test case.
kernel void compute(device float* outData [[ buffer(0) ]])
{
outData[0] = 234.5;
outData[3] = 345.6;
}
This "computed" data is stored in a MTLBuffer.
var buffer : MTLBuffer?
...
buffer = device.makeBuffer(length: MemoryLayout<Float>.size * 5, options: [])
...
commandBuffer.waitUntilCompleted()
At this point the kernel has written some test data to the MTLBuffer.
Question is how I should access that data from my main program?
I get a unsafeMutableRawPointer from buffer.contents(). How do I get a swift array of values that I can use everywhere else (displaying on screen, writing to file,...)?
These snippets work in this very simple app, but I am not sure if they are correct:
let raw = buffer.contents()
let b = raw.bindMemory(to: Float.self, capacity: 5)
print(b.advanced(by: 3).pointee)
let a = raw.assumingMemoryBound(to: Float.self)
print(a.advanced(by: 3).pointee)
let bufferPointer = UnsafeBufferPointer(start: b, count: 5)
let values = Array(bufferPointer)
print(values)
let value = raw.load(fromByteOffset: MemoryLayout<Float>.size * 3, as: Float.self)
print(value)
Both bindMemory and assumingMemoryBound work. Though assumingMemoryBound assumes the underlying bytes are already typed and bindMemory doesn't. I think that one of either should work, but not both. Which one should it be and why?
I use the code presented below to load to arrays, but I can't decide if mine or your version is best.
let count = 16
var array = [Float]()
array.reserveCapacity(count)
for i in 0..<count {
array.append(buffer.contents().load(fromByteOffset: MemoryLayout<Float>.size * i, as: Float.self))
}
I am trying to use a DynamoDB table to store this data:
DartsPlayerInsultTable
CustomerId String
PlayerId String
PlayerInsult String
Using the method (concept, not code) described here:
https://java.awsblog.com/post/Tx3GYZEVGO924K4/The-DynamoDBMapper-Local-Secondary-Indexes-and-You
here:
http://mobile.awsblog.com/post/TxTCW7KW8BGZAF/Amazon-DynamoDB-on-Mobile-Part-4-Local-Secondary-Indexes
and here:
http://labs.journwe.com/2013/12/15/dynamodb-secondary-indexes/comment-page-1/#comment-116
I want to have multiple insult records per customer-player.
CustomerId is my Hash Key
PlayerId is my Range Key
and I a trying to use PlayerInsult in a key so that
a second PlayerInsult value inserts a second record
rather than replacing the existing one.
Have tried both Global and Secondary indexes for this,
but if I try to add a row with a new insult, it still
replaces the insult with the same customer-player key
rather than adding a new one.
Any suggestions on the best approach to use for this is
DynanoDB? Do I need to create a hybrid column for a range-key?
Trying to keep this simple...
class func createDartsPlayerInsultTable() -> BFTask {
let dynamoDB = AWSDynamoDB.defaultDynamoDB()
let hashKeyAttributeDefinition = AWSDynamoDBAttributeDefinition()
hashKeyAttributeDefinition.attributeName = "CustomerId"
hashKeyAttributeDefinition.attributeType = AWSDynamoDBScalarAttributeType.S
let hashKeySchemaElement = AWSDynamoDBKeySchemaElement()
hashKeySchemaElement.attributeName = "CustomerId"
hashKeySchemaElement.keyType = AWSDynamoDBKeyType.Hash
let rangeKeyAttributeDefinition = AWSDynamoDBAttributeDefinition()
rangeKeyAttributeDefinition.attributeName = "PlayerId"
rangeKeyAttributeDefinition.attributeType = AWSDynamoDBScalarAttributeType.S
let rangeKeySchemaElement = AWSDynamoDBKeySchemaElement()
rangeKeySchemaElement.attributeName = "PlayerId"
rangeKeySchemaElement.keyType = AWSDynamoDBKeyType.Range
/*
let indexRangeKeyAttributeDefinition = AWSDynamoDBAttributeDefinition()
indexRangeKeyAttributeDefinition.attributeName = "PlayerInsult"
indexRangeKeyAttributeDefinition.attributeType = AWSDynamoDBScalarAttributeType.S
let rangeKeySchemaElement = AWSDynamoDBKeySchemaElement()
rangeKeySchemaElement.attributeName = "PlayerId"
rangeKeySchemaElement.keyType = AWSDynamoDBKeyType.Range
let indexRangeKeyElement = AWSDynamoDBKeySchemaElement()
indexRangeKeyElement.attributeName = "PlayerInsult"
indexRangeKeyElement.keyType = AWSDynamoDBIndexRangeKeyType.
*/
//Add non-key attributes
let playerInsultAttrDef = AWSDynamoDBAttributeDefinition()
playerInsultAttrDef.attributeName = "PlayerInsult"
playerInsultAttrDef.attributeType = AWSDynamoDBScalarAttributeType.S
let provisionedThroughput = AWSDynamoDBProvisionedThroughput()
provisionedThroughput.readCapacityUnits = 5
provisionedThroughput.writeCapacityUnits = 5
// CREATE GLOBAL SECONDARY INDEX
/*
let gsi = AWSDynamoDBGlobalSecondaryIndex()
let gsiArray = NSMutableArray()
let gsiHashKeySchema = AWSDynamoDBKeySchemaElement()
gsiHashKeySchema.attributeName = "PlayerId"
gsiHashKeySchema.keyType = AWSDynamoDBKeyType.Hash
let gsiRangeKeySchema = AWSDynamoDBKeySchemaElement()
gsiRangeKeySchema.attributeName = "PlayerInsult"
gsiRangeKeySchema.keyType = AWSDynamoDBKeyType.Range
let gsiProjection = AWSDynamoDBProjection()
gsiProjection.projectionType = AWSDynamoDBProjectionType.All;
gsi.keySchema = [gsiHashKeySchema,gsiRangeKeySchema];
gsi.indexName = "PlayerInsult";
gsi.projection = gsiProjection;
gsi.provisionedThroughput = provisionedThroughput;
gsiArray .addObject(gsi)
*/
// CREATE LOCAL SECONDARY INDEX
let lsi = AWSDynamoDBLocalSecondaryIndex()
let lsiArray = NSMutableArray()
let lsiHashKeySchema = AWSDynamoDBKeySchemaElement()
lsiHashKeySchema.attributeName = "CustomerId"
lsiHashKeySchema.keyType = AWSDynamoDBKeyType.Hash
let lsiRangeKeySchema = AWSDynamoDBKeySchemaElement()
lsiRangeKeySchema.attributeName = "PlayerInsult"
lsiRangeKeySchema.keyType = AWSDynamoDBKeyType.Range
let lsiProjection = AWSDynamoDBProjection()
lsiProjection.projectionType = AWSDynamoDBProjectionType.All;
lsi.keySchema = [lsiHashKeySchema,lsiRangeKeySchema];
lsi.indexName = "PlayerInsult";
lsi.projection = lsiProjection;
//lsi.provisionedThroughput = provisionedThroughput;
lsiArray .addObject(lsi)
//Create TableInput
let createTableInput = AWSDynamoDBCreateTableInput()
createTableInput.tableName = DartsPlayerInsultTableName;
createTableInput.attributeDefinitions = [hashKeyAttributeDefinition, rangeKeyAttributeDefinition, playerInsultAttrDef]
//createTableInput.attributeDefinitions = [hashKeyAttributeDefinition, rangeKeyAttributeDefinition]
createTableInput.keySchema = [hashKeySchemaElement, rangeKeySchemaElement]
createTableInput.provisionedThroughput = provisionedThroughput
//createTableInput.globalSecondaryIndexes = gsiArray as [AnyObject]
createTableInput.localSecondaryIndexes = lsiArray as [AnyObject]
return dynamoDB.createTable(createTableInput).continueWithSuccessBlock({ (var task:BFTask!) -> AnyObject! in
if ((task.result) != nil) {
// Wait for up to 4 minutes until the table becomes ACTIVE.
let describeTableInput = AWSDynamoDBDescribeTableInput()
describeTableInput.tableName = DartsPlayerInsultTableName;
task = dynamoDB.describeTable(describeTableInput)
for var i = 0; i < 16; i++ {
task = task.continueWithSuccessBlock({ (task:BFTask!) -> AnyObject! in
let describeTableOutput:AWSDynamoDBDescribeTableOutput = task.result as! AWSDynamoDBDescribeTableOutput
let tableStatus = describeTableOutput.table.tableStatus
if tableStatus == AWSDynamoDBTableStatus.Active {
return task
}
sleep(15)
return dynamoDB .describeTable(describeTableInput)
})
}
}
return task
})
}
Putting this as an answer and not another comment in case it gets long...
It sounds like the average user's insults might fit into a single record. With the disclaimer that I know absolutely nothing about swift, this might at least be something relatively simple. Keep your customer and player keys. Before you persist the insults, turn the whole list into one big string using whatever version of join("|") swift has. When you fetch the record, do a split("|") to get your list back. (Just be a little judicious with your choice of separators, I'm only using "|" as an example, you don't want to choose something that might appear in an insult...)
There's going to be that one user with enough insults to take you over the 400kb object limit. Set a max list size constant in your code -- when you turn your lists into strings to persist them to dynamo, check the player's list length against that limit. If you exceed it, break your list into chunks of that size and use hash and range keys like ("foo", "bar"), ("foo", "bar1"), ("foo", "bar2"), etc. Yes, the first one does not have a bucket number at the end...
When you query for the data, just do a straight query first and assume you'll be in the good case (just "foo" and "bar", no other buckets). When you unpack that first list, check its length. If it's equal to your max list size constant, you know that you got a "bad" user and need to do a range query. That second one can use the hash key "foo" and the range "bar" to "bar9999". You will fetch back all those buckets with that range query. Unpack and concatenate all the lists.
This is a little gory, but it should also ultimately be straight ahead to code up. Hopefully it's still simple enough to hook into the patterns you mentioned.
What I decided to do was make a conventional dynamodb table with just one hash key, but the new hash key is a combined string of:
CustomerId + "|" + PlayerId
It is not too hard to maintain synchrony between players and insults tables because once a player is inserted into the player table, modifying the player name results in a new row being inserted. Thus, insults do not need to be modified if the player name changes. You only need to cleanup insults if a player is deleted.
This update behavior is just the way dynamodb works if you make Player name a hash key, which I did to insure they were unique.
I am using Swift in a project, and using SQLite.swift for database handling. I am trying to retrieve the most recent entry from my database like below:
func returnLatestEmailAddressFromEmailsTable() -> String{
let dbPath = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true).first as String
let db = Database("\(dbPath)/db.sqlite3")
let emails = db["emails"]
let email = Expression<String>("email")
let time = Expression<Int>("time")
var returnEmail:String = ""
for res in emails.limit(1).order(time.desc) {
returnEmail = res[email]
println("from inside: \(returnEmail)")
}
return returnEmail
}
I am trying to test the returned string from the above function like this:
println("from outside: \(returnLatestEmailAddressFromEmailsTable())")
Note how I print the value from both inside and outside of the function. Inside, it works every single time. I am struggling with the "from outside:" part.
Sometimes the function returns the correct email, but sometimes it returns "" (presumably, the value was not set in the for loop).
How can I add "blocking" functionality so calling returnLatestEmailAddressFromEmailsTable() will always first evaluate the for loop, and only after this return the value?
Hello everyone this is my little Frankenstein code, don't make fun of it, it works!
So you would pass in the table name and a data as an Associative array which are objects.
I'm pretty sure this is not good code as I was and still am learning ActionScript. So what can I change or how would you guys make it better?
public function save(table:String,data:Object):void
{
var conn:SQLConnection = new SQLConnection();
var folder:File = File.applicationStorageDirectory;
var dbFile:File = folder.resolvePath("task.db");
conn.open(dbFile);
var stat:SQLStatement=new SQLStatement();
stat.sqlConnection=conn;
//make fields and values
var fields:String="";
var values:String="";
for(var sRole:String in data)
{
fields=fields+sRole+",:";
stat.parameters[":"+sRole]=data[sRole];
}
//trim off white space
var s:String=new String(fields);
var cleanString:String=s.slice( 0, -2 );
//over here we add : infront of the values I forget why
var find:RegExp=/:/g;
var mymyField:String=new String(cleanString.replace(find,""));
cleanString=":"+cleanString;
var SQLFields:String=mymyField;
var SQLValues:String=cleanString;
stat.text="INSERT INTO "+table+" ("+SQLFields+")VALUES("+SQLValues+")";
stat.execute();
}
The part where you build your query is quite a horror, to be honest. Half the code removes junk you added just a few lines before. This makes it hard to read and understand. Which is a sign of poor code quality. The following is far shorter and simpler:
//make fields and values
var fields:Array = [];
for(var field:String in data) {
fields.push(field);
stat.parameters[":"+field]=data[fieldName];
}
var sqlFields:String = fields.join(",");
var sqlValues:String = ":"+fields.join(",:");
stat.text="INSERT INTO "+table+" ("+sqlFields+")VALUES("+sqlValues+")";
stat.execute();
Someone once told me that a stupid idea that works isn't stupid. As programmer's our first goal is (often) to solve business issues; and as long as our code does that then we are successful. You don't need to apologize for code that works.
In terms of what I would do to change your snippet; I might just encapsulate it a bit more. Can the folder, dbFile, and db file name (task.db) be added either as properties to your class or arguments to the method?
Can you separate out the creation of the SQL Statement from the connection handling from your data parsing?
Some remarks,
As said before you can factorise out all the db connection so you can reuse the function without rewriting it if you need to change the db name.
Don't use new String() you can avoid it
it's not usefull to clean white space between your field :a, :b is the same as :a,:b
Some convention don't begin your local var name with an uppercase, and it's not usefull to reassign them to another var
If i don't get wrong after your //make fields and values can be rewritten for example as :
//make fields and values
var fields:String = "";
var values:String = "";
var fieldSeparator:String = "";
for(var sRole:String in data)
{
fields += fieldSeparator + sRole;
var paramName:String = ":" + sRole;
values += fieldSeparator + paramName;
stat.parameters[paramName] = data[sRole];
fieldSeparator = ",";
}
stat.text = "INSERT INTO " + table +" (" + fields + ") VALUES (" + values + ")";
stat.execute();