Re: data associated with a particular state
I would use 3 records: (defrecord DownNode [] SomeInterfaceApplicableToDownState (wake-up [_] (-WaitingNode)) ... InterfaceApplicableToAllNodes ...) (defrecord WaitingNode [] SomeInterfaceApplicableToWaitingState (shutdown [_] (-DownNode)) (execute [_ job-id] (-RunningNode job-id)) ... InterfaceApplicableToAllNodes ...) (defrecord RunningNode [job-id] SomeInterfaceApplicableToRunningState ... InterfaceApplicableToAllNodes ...) After all, you won't be bashing the state of node in place, you will be constructing a new node at each modification. (unless you define the attrs mutable) On Tue, Mar 25, 2014 at 5:20 PM, László Török ltoro...@gmail.com wrote: AFAIK the only thing that records do not support compared to StructMaps is namespaced keyword lookup, i.e. (:some-ns/a-key a-record). If you do not need this, you should consider using records. Las On Tue, Mar 25, 2014 at 4:52 PM, Moritz Ulrich mor...@tarn-vedra.dewrote: The data type created by defstruct isn't anything more than a map which can store the specified fields a bit more efficient than 'normal' maps. You can just `assoc' any other key-value pairs as in any other map. Also, have a look at records - I think StructMaps have been deprecated (or at least aren't recommended anymore) for some time now. A record (`defrecord') will do pretty much the same, just nicer ;-) On Tue, Mar 25, 2014 at 1:51 AM, cmhowa...@alaska.edu wrote: Hi. I'm very new to Clojure, but I've read most of the functional programming tutorial http://java.ociweb.com/mark/clojure/article.html . Suppose I have a data structure called node that can be in one of a number of different states -- namely, down, waiting, and running. Suppose that in the running state, the node has a job-id number associated with it, but such a number is not applicable in the other two states. Should I add an extra field, and only check that field in the running state, like so... (defstruct node :state :job-id) Or is there some better, or more clojure-ish, way to approach this? If I was doing this in Haskell, I think that I would perhaps make some kind of algebraic NodeState data type, and have the JobId only attached to the Running constructor. -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups Clojure group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups Clojure group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups Clojure group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout. -- Kind Regards, Atamert Ölçgen -+- --+ +++ www.muhuk.com -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups Clojure group. To unsubscribe from this
Re: data associated with a particular state
The data type created by defstruct isn't anything more than a map which can store the specified fields a bit more efficient than 'normal' maps. You can just `assoc' any other key-value pairs as in any other map. Also, have a look at records - I think StructMaps have been deprecated (or at least aren't recommended anymore) for some time now. A record (`defrecord') will do pretty much the same, just nicer ;-) On Tue, Mar 25, 2014 at 1:51 AM, cmhowa...@alaska.edu wrote: Hi. I'm very new to Clojure, but I've read most of the functional programming tutorial http://java.ociweb.com/mark/clojure/article.html. Suppose I have a data structure called node that can be in one of a number of different states -- namely, down, waiting, and running. Suppose that in the running state, the node has a job-id number associated with it, but such a number is not applicable in the other two states. Should I add an extra field, and only check that field in the running state, like so... (defstruct node :state :job-id) Or is there some better, or more clojure-ish, way to approach this? If I was doing this in Haskell, I think that I would perhaps make some kind of algebraic NodeState data type, and have the JobId only attached to the Running constructor. -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups Clojure group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups Clojure group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: data associated with a particular state
AFAIK the only thing that records do not support compared to StructMaps is namespaced keyword lookup, i.e. (:some-ns/a-key a-record). If you do not need this, you should consider using records. Las On Tue, Mar 25, 2014 at 4:52 PM, Moritz Ulrich mor...@tarn-vedra.de wrote: The data type created by defstruct isn't anything more than a map which can store the specified fields a bit more efficient than 'normal' maps. You can just `assoc' any other key-value pairs as in any other map. Also, have a look at records - I think StructMaps have been deprecated (or at least aren't recommended anymore) for some time now. A record (`defrecord') will do pretty much the same, just nicer ;-) On Tue, Mar 25, 2014 at 1:51 AM, cmhowa...@alaska.edu wrote: Hi. I'm very new to Clojure, but I've read most of the functional programming tutorial http://java.ociweb.com/mark/clojure/article.html. Suppose I have a data structure called node that can be in one of a number of different states -- namely, down, waiting, and running. Suppose that in the running state, the node has a job-id number associated with it, but such a number is not applicable in the other two states. Should I add an extra field, and only check that field in the running state, like so... (defstruct node :state :job-id) Or is there some better, or more clojure-ish, way to approach this? If I was doing this in Haskell, I think that I would perhaps make some kind of algebraic NodeState data type, and have the JobId only attached to the Running constructor. -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups Clojure group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups Clojure group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups Clojure group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
data associated with a particular state
Hi. I'm very new to Clojure, but I've read most of the functional programming tutorial http://java.ociweb.com/mark/clojure/article.html. Suppose I have a data structure called node that can be in one of a number of different states -- namely, down, waiting, and running. Suppose that in the running state, the node has a job-id number associated with it, but such a number is not applicable in the other two states. Should I add an extra field, and only check that field in the running state, like so... (defstruct node :state :job-id) Or is there some better, or more clojure-ish, way to approach this? If I was doing this in Haskell, I think that I would perhaps make some kind of algebraic NodeState data type, and have the JobId only attached to the Running constructor. -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups Clojure group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
