AngouriMath

Navigation

Home Quick start Wiki Almanac Research What's new Try Use Angouri.org GitHub Report a bug Donate Contacts

AngouriMath.Convenience

← Back to list of namespaces

Classes within the AngouriMath.Convenience namespace

• ISettingState

  Summary

  A setting, without its value's type — enough to ask what it currently reads as.

• Setting`1

  Summary

  This class for configuring some internal mechanisms from outside
  

  Type parameter "T"

  Those configurations can be of different types
  

  Remarks

  A setting is one object for the whole process, and what it holds is per *flow*, not
  per thread: the stack of values lives in an AsyncLocal`1. A scope
  opened before an await is therefore still in force after it, and a
  scope opened inside a task is invisible to that task's siblings and to whatever
  started it. Backing the field with [ThreadStatic] gave neither: a continuation
  resumed on a pool thread saw the defaults, and a thread returned to the pool carried
  whatever scope was left on it into the next caller.
  The frames are immutable, which is what makes the reference safe to share. An
  AsyncLocal`1 copies on assignment to Value and on nothing else, so if a frame could be mutated in place, two flows holding the
  same chain would write over each other. Pushing and popping therefore build a new
  chain and assign it, rather than editing one.
  

• SettingsState

  Summary

  What every setting reads as, taken together, so that something holding a result computed
  under the settings of a moment can tell whether those settings still hold.
  

  Remarks

  A state and not a change count. Counting changes looks equivalent and is not: a
  scope opened and closed leaves every setting exactly as it found it while moving a
  counter twice, and the library opens such scopes constantly — a single
  Simplify of one unevaluated integral opened 3520 of them, all four from
  numeric downcasting in Number/Operators.cs. A counter therefore reports
  "everything has changed" continuously and is useless to a cache. Measured, not assumed:
  the counter was built first and threw away the whole benefit.
  The state of one setting is the reference to the frame on top of its stack, which
  is exact rather than a hash — releasing a scope restores the very frame object that was
  there before it, since the chain below a pushed frame is never rebuilt. So comparing
  snapshots is a handful of reference comparisons with no chance of collision, and a
  balanced open-and-close compares equal, which is the whole point.