3 ms·

Thanks, seems like the thing I'm looking for. If you look at line 531 of the CPU source code (as of today, anyway), there are multiple 256 byte tables that giv

by beagle3 12y ago

Thanks, seems like the thing I'm looking for. If you look at line 531 of the CPU source code (as of today, anyway), there are multiple 256 byte tables that give instruction encodings, lengths, and cycle counts. What I was asking is: "Is it possible to put these as a parameter of the 'op' macro so that it builds these tables automatically" The answer might be "No" if e.g. a single op has multiple instruction encodings. But assume that there is only one encoding per op. An equivalent question is - can static: sections assign to an array that will be available at runtime? From your example, the answer appears to be yes.

filwit 12y ago
> can static: sections assign to an array that will be available at runtime? The answer is yes, but it's a tad trickier than just accessing the compile-time list from run-time code (which doesn't make sense, and is illegal). Instead, use a macro to generate a bunch of run-time checks against a specific value. Eg: var eventNames {.compileTime.} = newSeq[string]() proc defineEvent(name:static[string]) = static: eventNames.add(name) macro checkDefined(name): stmt = # begin new statement result = newStmtList().add quote do: echo "Checking for '", `name`, "'" # loop over every known event name and # build a run-time 'if' check for each one. for n in eventNames: result.add quote do: if `n` == `name`: echo "Found it!" # add some events to compile-time list defineEvent("foo") defineEvent("bar") # define some runtime values let eventName1 = "foo" let eventName2 = "blah" # check runtime values againts compile-time list checkDefined(eventName1) checkDefined(eventName2) # output: # Checking for 'foo' # Found it! # Checking for 'blah' Note: This will inject a bunch of 'if' statements for each call to 'checkDefined', which might bloat your code.. it's probably better to make a macro which defines a proc, then just call that to check run-time values.. but I left those kinds of details out of this illustration for the sake of simplicity.
- beagle3 12y ago
  Thanks. I'm sure there's a way to promote a compile time seq into a constant runtime one. Might require some more macro trickery, though.
  - filwit 12y ago
    Err... what you said just reminded me of something, and I realized all the code I just showed you is really over-complicated and that Nim has much more straight forward options using `const`, like this: static: # define a compile-time list first var names = newSeq[string]() # add some values (at compile-time) names.add("foo") names.add("bar") # define the compiler vars as run-time const const runtimeNames = names # define some run-time variables var name1 = "foo" var name2 = "blah" # check runtime variables against const variable if runtimeNames.contains(name1): echo "Has Foo!" if runtimeNames.contains(name2): echo "Has Blah!" Sorry about the rather winded (and bad example) replys :| But thanks for the conversation, it reminded me of this and now I have some cleaning up of my own code to get too. Cheers!

by beagle3 12y ago

filwit 12y ago

> can static: sections assign to an array that will be available at runtime? The answer is yes, but it's a tad trickier than just accessing the compile-time list from run-time code (which doesn't make sense, and is illegal). Instead, use a macro to generate a bunch of run-time checks against a specific value. Eg: var eventNames {.compileTime.} = newSeq[string]() proc defineEvent(name:static[string]) = static: eventNames.add(name) macro checkDefined(name): stmt = # begin new statement result = newStmtList().add quote do: echo "Checking for '", `name`, "'" # loop over every known event name and # build a run-time 'if' check for each one. for n in eventNames: result.add quote do: if `n` == `name`: echo "Found it!" # add some events to compile-time list defineEvent("foo") defineEvent("bar") # define some runtime values let eventName1 = "foo" let eventName2 = "blah" # check runtime values againts compile-time list checkDefined(eventName1) checkDefined(eventName2) # output: # Checking for 'foo' # Found it! # Checking for 'blah' Note: This will inject a bunch of 'if' statements for each call to 'checkDefined', which might bloat your code.. it's probably better to make a macro which defines a proc, then just call that to check run-time values.. but I left those kinds of details out of this illustration for the sake of simplicity.

beagle3 12y ago
Thanks. I'm sure there's a way to promote a compile time seq into a constant runtime one. Might require some more macro trickery, though.
- filwit 12y ago
  Err... what you said just reminded me of something, and I realized all the code I just showed you is really over-complicated and that Nim has much more straight forward options using `const`, like this: static: # define a compile-time list first var names = newSeq[string]() # add some values (at compile-time) names.add("foo") names.add("bar") # define the compiler vars as run-time const const runtimeNames = names # define some run-time variables var name1 = "foo" var name2 = "blah" # check runtime variables against const variable if runtimeNames.contains(name1): echo "Has Foo!" if runtimeNames.contains(name2): echo "Has Blah!" Sorry about the rather winded (and bad example) replys :| But thanks for the conversation, it reminded me of this and now I have some cleaning up of my own code to get too. Cheers!