LocSta2 0.0.1

.NET 10.0 This package targets .NET 10.0. The package is compatible with this framework or higher. 
dotnet add package LocSta2 --version 0.0.1
                    


                    

                
NuGet\Install-Package LocSta2 -Version 0.0.1
This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package. 
<PackageReference Include="LocSta2" Version="0.0.1" />
For projects that support PackageReference, copy this XML node into the project file to reference the package. 
<PackageVersion Include="LocSta2" Version="0.0.1" />
                    


                            Directory.Packages.props
                        

                    

                
<PackageReference Include="LocSta2" />
                    


                            Project file
For projects that support Central Package Management (CPM), copy this XML node into the solution Directory.Packages.props file to version the package. 
paket add LocSta2 --version 0.0.1
                    


                    

                
#r "nuget: LocSta2, 0.0.1"
#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package. 
#:package LocSta2@0.0.1
#:package directive can be used in C# file-based apps starting in .NET 10 preview 4. Copy this into a .cs file before any lines of code to reference the package. 
#addin nuget:?package=LocSta2&version=0.0.1
                    


                            Install as a Cake Addin
                        

                    

                
#tool nuget:?package=LocSta2&version=0.0.1
                    


                            Install as a Cake Tool

<p align="center"> <img src="LocSta_logo.png" alt="LocSta logo" width="200" /> </p>

<h1 align="center">LocSta</h1>

<p align="center"> <strong>Loc</strong>al <strong>Sta</strong>te — A stateful stream processing library for F#. </p>

<p align="center"> <a href="https://fsprojects.github.io/LocSta/">Live Demo</a> </p>

LocSta provides composable, stateful stream blocks using F# computation expressions. Each block is a pure function that threads state automatically, making it easy to build complex signal processing pipelines — from simple counters to full audio DSP chains.

Core Concept

A SigStream<'v,'c,'s> is a function that takes a StateController and a context value, and returns a sequence of output values along with the updated state. The stream { } computation expression composes these blocks, automatically managing state allocation and threading. Streams can emit zero, one, or multiple values per tick using yield.

open LocSta.Core

// A simple stateful stream: counter that increments by 1
let myCounter =
    stream {
        let! state = useState 0
        let current = state.Value
        state.Value <- current + 1
        return current
    }

// Evaluate 5 samples (context is unit here)
let result = myCounter |> Eval.run 5 (fun _ -> ())
// result = [0; 1; 2; 3; 4]

Key Primitives

Primitive Description
stream { } Computation expression builder for composing streams
return / yield Emit a single value (yield allows multi-emit with Combine)
yield! Forward all values from a sub-stream
getCtx() Read the current input/context value
useState value Local mutable state, initialized once
useStateWith init Local mutable state with lazy initializer
useMemoWith init Memoized value (lazy, computed once)
ofSeq sequence Create a stream from a sequence (emits empty when exhausted)
map proj stream Transform stream output
Eval.run n getCtx stream Evaluate n values with a context generator
Eval.runWith inputs stream Evaluate with an input sequence
Eval.toSeq getCtx stream Convert to a lazy seq<'v> (stops after 1000 silent ticks)
Eval.toSeqWith max getCtx stream Same with custom silent-tick limit

Examples

Exponential Moving Average

open LocSta
open LocSta.Blocks.Statistics.Ema

let inputs = [1.0; 2.0; 3.0; 4.0; 5.0]
let result = ema 0.5 |> Eval.runWith inputs
// Smoothed output approaching the input signal

Composing Streams

open LocSta
open LocSta.Blocks.Operators

let stream1 = ofSeq [1.0; 2.0; 3.0]
let stream2 = ofSeq [10.0; 20.0; 30.0]
let summed = stream1 .+. stream2
let result = summed |> Eval.run 3 (fun _ -> ())
// result = [11.0; 22.0; 33.0]

Audio: Filtered Sine Oscillator

open LocSta
open LocSta.Blocks.Dsp.Oscillators.SineOsc
open LocSta.Blocks.Dsp.Filters.LowPass1

let sampleRate = 44100.0

let filtered =
    stream {
        let! osc = sineOsc sampleRate
        let! out = lowPass1 sampleRate
        // ... wire osc through filter
        return out
    }

Counting Events

open LocSta
open LocSta.Blocks.Counting.CountWhere

let inputs = [1; 5; 3; 7; 2; 8]
let result = countWhere (fun x -> x > 4) |> Eval.runWith inputs
// result = [0; 1; 1; 2; 2; 3]

Available Blocks

<details> <summary><strong>Generators</strong></summary>

Block Description
counter start increment Incrementing counter
fibonacci Fibonacci sequence generator

</details>

<details> <summary><strong>Delay</strong></summary>

Block Description
delayBy1 seed Delay signal by 1 sample
delayByN n seed Delay signal by n samples

</details>

<details> <summary><strong>State</strong></summary>

Block Description
hold predicate defaultValue Hold last value satisfying predicate
latch gate Latch value when gate is true
edge Detect rising edges (false → true)
changed Detect value changes

</details>

<details> <summary><strong>Arithmetic</strong></summary>

Block Description
diff Difference between consecutive samples
cumulativeSum Running cumulative sum
cumulativeProduct Running cumulative product
clamp lo hi Clamp to [lo, hi] range
rescale inMin inMax outMin outMax Linear rescaling between ranges

</details>

<details> <summary><strong>Statistics</strong></summary>

Block Description
movingAverage windowSize Simple moving average
ema alpha Exponential moving average
rollingStdDev windowSize Standard deviation over window
rollingMin windowSize Minimum over sliding window
rollingMax windowSize Maximum over sliding window
runningMin All-time running minimum
runningMax All-time running maximum

</details>

<details> <summary><strong>Detection</strong></summary>

Block Description
crossover threshold Detect threshold crossings
threshold lo hi Hysteresis threshold (Schmitt trigger)

</details>

<details> <summary><strong>Logic</strong></summary>

Block Description
debounce count Debounce boolean signal
toggle Toggle on each true input

</details>

<details> <summary><strong>Counting</strong></summary>

Block Description
countWhere predicate Count predicate satisfactions
countSince predicate Samples since predicate was last true
countIn windowSize Count true values in window
timeSince predicate dt Time elapsed since predicate
rate windowSize dt Event rate over window

</details>

<details> <summary><strong>Windowing</strong></summary>

Block Description
windowedReduce windowSize folder seed Fold over sliding window
segment predicate Segment stream by predicate

</details>

<details> <summary><strong>TimeSeries — Types</strong></summary>

Type Description
DataPoint<'v> A value with a DateTimeOffset timestamp
ResampleContext<'v> Window of DataPoints with optional before/after neighbors
Resampler<'v,'r> ResampleContext<'v> -> 'r — aggregation or interpolation function

</details>

<details> <summary><strong>TimeSeries — LookBack</strong></summary>

Block Description
lookBack1Opt () Previous DataPoint as voption (ValueNone on first tick)
lookBack1 default Previous DataPoint, padded with default
lookBack2Opt () / lookBack3Opt () Previous 2/3 DataPoints as voption tuple
lookBack2 default / lookBack3 default Previous 2/3 DataPoints, padded with default
lookBackOpt n Previous N DataPoints as voption list
lookBack n default Previous N DataPoints as list, padded with default

</details>

<details> <summary><strong>TimeSeries — LookAhead</strong></summary>

Block Description
lookAhead1Opt () (current, next) as voption — delays 1 tick
lookAhead1 default (current, next) — uses default before buffer fills
lookAhead2Opt () / lookAhead3Opt () (current, next1, next2/3) as voption — delays 2/3 ticks
lookAhead2 default / lookAhead3 default (current, next1, next2/3) padded with default
lookAheadOpt n (current, ahead list) as voption — delays N ticks
lookAhead n default (current, ahead list) — padded with default

</details>

<details> <summary><strong>TimeSeries — Window Aggregation</strong></summary>

Block Description
window n Sliding window of N DataPoints (raw buffer)
windowSum n Sum of values in sliding window. Input: DataPoint<float>
windowAvg n Average of values in sliding window
windowMin n Minimum value in sliding window
windowMax n Maximum value in sliding window
windowCount n Count of values in window (saturates at N)
cumulativeSum () Running total over all values
intervalSum () Cumulative sum that resets on boundary. Input: (DataPoint<float> * bool)

</details>

<details> <summary><strong>TimeSeries — Interpolation</strong></summary>

Block Description
sampleAndHold () Hold last known value at target timestamp. Input: (DateTimeOffset * DataPoint<'v> voption)
nearestNeighbor () Pick closest point by timestamp. Input: (DateTimeOffset * DataPoint<float> voption)
linear () Linear interpolation between surrounding points. Input: (DateTimeOffset * DataPoint<float> voption)

</details>

<details> <summary><strong>TimeSeries — Standalone Resamplers</strong></summary>

Block Description
Aggregate.last / first / count Last/first value, count in window
Aggregate.sum / avg / min / max Numeric aggregations over ResampleContext
Interpolate.sampleAndHold Hold last known value
Interpolate.nearestNeighbor Pick nearest value by timestamp
Interpolate.linear Linear interpolation (float only)

</details>

<details> <summary><strong>Operators</strong></summary>

Block Description
binOp op s1 s2 Combine two streams with binary operator
s1 .+. s2 Add two streams
s1 .-. s2 Subtract two streams
s1 .*. s2 Multiply two streams
s1 ./. s2 Divide two streams

</details>

<details> <summary><strong>DSP — Oscillators</strong></summary>

Block Description
sineOsc sampleRate Sine wave oscillator. Input: frequency
sawOsc sampleRate Sawtooth oscillator. Input: frequency
squareOsc sampleRate Square wave with pulse width. Input: (freq, pulseWidth)
triangleOsc sampleRate Triangle wave oscillator. Input: frequency
whiteNoise seed Seeded white noise generator

</details>

<details> <summary><strong>DSP — Filters</strong></summary>

Block Description
lowPass1 sampleRate 1-pole RC low-pass. Input: (signal, cutoffHz)
highPass1 sampleRate 1-pole high-pass. Input: (signal, cutoffHz)
biquadLowPass sampleRate 2nd-order resonant low-pass. Input: (signal, cutoff, q)
biquadHighPass sampleRate 2nd-order resonant high-pass. Input: (signal, cutoff, q)
biquadBandPass sampleRate 2nd-order band-pass. Input: (signal, cutoff, q)
dcBlock r DC blocking filter with configurable R

</details>

<details> <summary><strong>DSP — Envelope</strong></summary>

Block Description
envFollow attackMs releaseMs sampleRate Envelope follower. Input: signal
adsr attackTime decayTime sustainLevel releaseTime ADSR envelope generator. Input: gate (bool)

</details>

<details> <summary><strong>DSP — Dynamics</strong></summary>

Block Description
softClip drive Soft clipper via tanh saturation. Input: signal
hardClip threshold Hard clipper/limiter. Input: signal
gate threshold Noise gate. Input: (signal, envelope)

</details>

<details> <summary><strong>DSP — Modulation</strong></summary>

Block Description
ringMod s1 s2 Ring modulator (multiply two streams)
bitCrush bits Bit depth reducer. Input: signal
crossfade s1 s2 mix Crossfade between two streams

</details>

<details> <summary><strong>DSP — Analysis</strong></summary>

Block Description
rms windowSize RMS level over sliding window
zeroCrossRate windowSize Zero crossing rate over window
peakHold decayRate Peak hold with exponential decay

</details>

Building & Testing

dotnet build
dotnet test

Running the Demo Site

npm install
npm start

License

MIT

Product Compatible and additional computed target framework versions.
.NET net10.0 is compatible.  net10.0-android was computed.  net10.0-browser was computed.  net10.0-ios was computed.  net10.0-maccatalyst was computed.  net10.0-macos was computed.  net10.0-tvos was computed.  net10.0-windows was computed. 
Compatible target framework(s)
Included target framework(s) (in package)
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Version Downloads Last Updated
0.0.1 116 4/6/2026