blockly minting (#2825)

* update mechanism to use average block time
* correctly sets accum height for zero-delegations
* update Decimal Format()
* clip withdrawal tokens
* PositiveDelegationInvariant
* DelegatorSharesInvariant
* DelAccumInvariants

docs/spec/mint/begin_block.md

@@ -1,18 +1,18 @@
 # Begin-Block
 
-## Inflation 
+Inflation occurs at the beginning of each block, however minting parameters
+are only calculated once per hour.
 
-Inflation occurs at the beginning of each block. 
+## NextInflationRate
 
-### NextInflation
+The target annual inflation rate is recalculated at the first block of each new
+hour. The inflation is also subject to a rate change (positive or negative)
+depending on the distance from the desired ratio (67%). The maximum rate change
+possible is defined to be 13% per year, however the annual inflation is capped
+as between 7% and 20%.
 
-The target annual inflation rate is recalculated for each provisions cycle. The
-inflation is also subject to a rate change (positive or negative) depending on
-the distance from the desired ratio (67%). The maximum rate change possible is
-defined to be 13% per year, however the annual inflation is capped as between
-7% and 20%.
-
-NextInflation(params Params, bondedRatio sdk.Dec) (inflation sdk.Dec) {
+```
+NextInflationRate(params Params, bondedRatio sdk.Dec) (inflation sdk.Dec) {
 	inflationRateChangePerYear = (1 - bondedRatio/params.GoalBonded) * params.InflationRateChange
 	inflationRateChange = inflationRateChangePerYear/hrsPerYr
 
@@ -26,3 +26,25 @@ NextInflation(params Params, bondedRatio sdk.Dec) (inflation sdk.Dec) {
 	}
 
 	return inflation
+```
+
+## NextAnnualProvisions
+
+Calculate the annual provisions based on current total supply and inflation
+rate. This parameter is calculated once per block. 
+
+```
+NextAnnualProvisions(params Params, totalSupply sdk.Dec) (provisions sdk.Dec) {
+	return Inflation * totalSupply
+```
+
+## BlockProvision
+
+Calculate the provisions generated for each block based on current 
+annual provisions 
+
+```
+BlockProvision(params Params) sdk.Coin {
+	provisionAmt = AnnualProvisions/ params.BlocksPerYear
+	return sdk.NewCoin(params.MintDenom, provisionAmt.Truncate())
+```

docs/spec/mint/state.md

@@ -8,8 +8,9 @@ The minter is a space for holding current inflation information.
 
 ```golang
 type Minter struct {
-	InflationLastTime time.Time // block time which the last inflation was processed
-	Inflation         sdk.Dec   // current annual inflation rate
+	LastUpdate       time.Time // time which the last update was made to the minter
+	Inflation        sdk.Dec   // current annual inflation rate
+	AnnualProvisions sdk.Dec   // current annual exptected provisions
 }
 ```
 
@@ -26,6 +27,7 @@ type Params struct {
 	InflationMax        sdk.Dec // maximum inflation rate
 	InflationMin        sdk.Dec // minimum inflation rate
 	GoalBonded          sdk.Dec // goal of percent bonded atoms
+	BlocksPerYear       uint64   // expected blocks per year
 }
 ```