andyibanez / modern-concurrency-on-apple-platforms-book-code Goto Github PK

I couldn't find a better way to contact you, so I decided to post here. Hope you don't mind.

I absolutely love your book! I received it as a Christmas gift and devoured it. Here's a list of errata items and suggestions. I know I could have submitted them directly to Apress, but that would require me to submit them one at a time and it would take too long.

• p. xviii: I recommend mentioning that
  code for the exercises is available at
  https://github.com/AndyIbanex/modern-concurrency-on-apple-platforms-book-code
• p. 9: "such us shared" -> "such as shared"
• p. 35: "a few ways" -> "two ways" since only two are described
• p. 44: "avoid code reuse" -> "avoid code repetition"
• p. 49: "calculated properties" -> "computed properties" (Apple terminology)
• p. 85: "they begin executing" -> "they can begin executing"
  since the task group could determine that it should wait to execute
  the task because there are already too many tasks running
• p. 91: It would be good to point out that
  "background" and "low" are the same,
  "high" and "userInitiated" are the same, and
  "medium" and "utility" are the same.
• p. 100 I was confused initially when I read
  "the images will always show up in the same order",
  but then I realized you meant that the vertical order of the
  images on the screen will match their order in the Array.
• p. 101 "new child task" -> "new implicit child task"
  to make this more clear
• p. 117 "and if they mutate, a copy is created" ->
  "and if they mutate, a copy-on-write copy is created"
  to emphasize that a full copy is not made immediately
• p. 119 "If it were a struct" -> "If it were a value type"
  to emphasize that the statement is not specific to structs
• p. 142 "and have read-only properties" ->
  "and only have read-only properties"
  to emphasize that Sendable types cannot have any mutable properties
• p. 148 "Finally, if you have a variable" -> "If you have a variable"
  because you use "Finally" again later on the page
• p. 153 "As iOS 15" -> "As of iOS 15"
• p. 172 "Struct" -> "struct"
• p. 172 "Func" -> "func"
• p. 174 "Func" -> "func"
• p. 176 "For" -> "for"
• p. 176 "Let" -> "let"
• p. 177 "Each command" -> "Each line" since
  what is being read from stdin is not necessarily commands.
• p. 186 "no danger or recursive calls" -> "no danger of recursive calls"
• p. 187 In Listing 9-18, "self" -> "let"
• p. 194 "hierarchy were" -> "hierarchy where"

If there's a better place for me to ask questions about the book than here, please let me know. I'm happy to post them elsewhere.

On page 175 you say "If you use the same async sequence in another loop, you will get the data instantly, because it will be cached."

I wonder what happens if the sequence is very long and/or the values it returns are very large. It seems like the app could crash due to running out of memory. I wonder if it only caches the values if there is enough free memory to do so.

I also wonder if it is possible to create an infinite AsyncSequence that never stops returning values ... in which case it definitely couldn't cache all the values.