diff --git a/fermi.go b/fermi.go index 09b3e07..57d35ee 100644 --- a/fermi.go +++ b/fermi.go @@ -12,29 +12,62 @@ import ( "strings" ) -const NORMAL90CONFIDENCE = 1.6448536269514727 -const GENERAL_ERR_MSG = "Valid inputs: 2 || * 2 || / 2 || 2 20 || * 2 20 || / 2 20 || clean || =: var || op var || clean || help || debug || exit" -const N_SAMPLES = 100_000 +/* Types and interfaces */ -// Distribution interface -// https://go.dev/tour/methods/9 +type Stack struct { + old_dist Dist + vars map[string]Dist +} type Dist interface { Samples() []float64 } + type Scalar float64 + type Lognormal struct { low float64 high float64 } + type Beta struct { a float64 b float64 } + type FilledSamples struct { xs []float64 } +/* Constants */ +const GENERAL_ERR_MSG = " Operation | Variable assignment | Special\n" + + " Operation: operator operand\n" + + " operator: (empty) | * | / | + | -\n" + + " operand: scalar | lognormal | beta | variable\n" + + " lognormal: low high\n" + + " beta: beta alpha beta\n" + + " Variable assignment: =: variable_name\n" + + " Clear stack: . | c | clear\n" + + " Variable assignment and clear stack: =. variable_name\n" + + " Other special operations: help | debug | exit\n" + + " Examples: \n" + + " + 2\n" + + " / 2.5\n" + + " * 1 10 (interpreted as lognormal)\n" + + " + 1 10\n" + + " * beta 1 10\n" + + " 1 10 (multiplication taken as default operation)\n" + + " =: x\n" + + " .\n" + + " 1 100\n" + + " + x\n" + + " exit\n" +const NORMAL90CONFIDENCE = 1.6448536269514727 +const INIT_DIST Scalar = Scalar(1) +const N_SAMPLES = 100_000 + +/* Dist interface functions */ +// https://go.dev/tour/methods/9 func (p Scalar) Samples() []float64 { xs := make([]float64, N_SAMPLES) for i := 0; i < N_SAMPLES; i++ { @@ -42,29 +75,34 @@ func (p Scalar) Samples() []float64 { } return xs } + func (ln Lognormal) Samples() []float64 { sampler := func(r sample.Src) float64 { return sample.Sample_to(ln.low, ln.high, r) } // return sample.Sample_parallel(sampler, N_SAMPLES) // Can't do parallel because then I'd have to await throughout the code return sample.Sample_serially(sampler, N_SAMPLES) } + func (beta Beta) Samples() []float64 { sampler := func(r sample.Src) float64 { return sample.Sample_beta(beta.a, beta.b, r) } // return sample.Sample_parallel(sampler, N_SAMPLES) return sample.Sample_serially(sampler, N_SAMPLES) } + func (fs FilledSamples) Samples() []float64 { return fs.xs } // Parse line into Distribution + func parseLineErr(err_msg string) (string, Dist, error) { fmt.Println(GENERAL_ERR_MSG) fmt.Println(err_msg) var errorDist Dist return "", errorDist, errors.New(err_msg) } -func parseLine(line string, vars map[string]Dist) (string, Dist, error) { + +func parseLineIntoOpAndDist(line string, vars map[string]Dist) (string, Dist, error) { words := strings.Split(strings.TrimSpace(line), " ") op := "" @@ -138,7 +176,7 @@ func multiplyBetaDists(beta1 Beta, beta2 Beta) Beta { return Beta{a: beta1.a + beta2.a, b: beta1.b + beta2.b} } -func operateAsSamples(dist1 Dist, dist2 Dist, op string) (Dist, error) { +func operateDistsAsSamples(dist1 Dist, dist2 Dist, op string) (Dist, error) { xs := dist1.Samples() ys := dist2.Samples() @@ -179,7 +217,7 @@ func multiplyDists(old_dist Dist, new_dist Dist) (Dist, error) { case Scalar: return multiplyLogDists(o, Lognormal{low: float64(n), high: float64(n)}), nil default: - return operateAsSamples(old_dist, new_dist, "*") + return operateDistsAsSamples(old_dist, new_dist, "*") } } case Scalar: @@ -193,7 +231,7 @@ func multiplyDists(old_dist Dist, new_dist Dist) (Dist, error) { case Scalar: return Scalar(float64(o) * float64(n)), nil default: - return operateAsSamples(old_dist, new_dist, "*") + return operateDistsAsSamples(old_dist, new_dist, "*") } } case Beta: @@ -201,10 +239,10 @@ func multiplyDists(old_dist Dist, new_dist Dist) (Dist, error) { case Beta: return multiplyBetaDists(o, n), nil default: - return operateAsSamples(old_dist, new_dist, "*") + return operateDistsAsSamples(old_dist, new_dist, "*") } default: - return operateAsSamples(old_dist, new_dist, "*") + return operateDistsAsSamples(old_dist, new_dist, "*") } } @@ -219,7 +257,7 @@ func divideDists(old_dist Dist, new_dist Dist) (Dist, error) { case Scalar: return multiplyLogDists(o, Lognormal{low: 1.0 / float64(n), high: 1.0 / float64(n)}), nil default: - return operateAsSamples(old_dist, new_dist, "/") + return operateDistsAsSamples(old_dist, new_dist, "/") } } case Scalar: @@ -230,31 +268,16 @@ func divideDists(old_dist Dist, new_dist Dist) (Dist, error) { case Scalar: return Scalar(float64(o) / float64(n)), nil default: - return operateAsSamples(old_dist, new_dist, "/") + return operateDistsAsSamples(old_dist, new_dist, "/") } } default: - return operateAsSamples(old_dist, new_dist, "/") + return operateDistsAsSamples(old_dist, new_dist, "/") } } -func joinDists(old_dist Dist, new_dist Dist, op string) (Dist, error) { - - switch op { - case "*": - return multiplyDists(old_dist, new_dist) - case "/": - return divideDists(old_dist, new_dist) - case "+": - return operateAsSamples(old_dist, new_dist, "+") - case "-": - return operateAsSamples(old_dist, new_dist, "-") - default: - return old_dist, errors.New("Can't combine distributions in this way") - } -} - -/* Pretty print distributions */ +/* Pretty print distributions + */ func prettyPrintInt(n int) { switch { case math.Abs(float64(n)) >= 1_000_000_000_000: @@ -338,11 +361,32 @@ func prettyPrintDist(dist Dist) { /* Combine old dist and new line */ // We want this as a function to be able to have parenthesis/recusion, possibly functions -const init_dist Scalar = Scalar(1) +func combineStackAndDist(stack Stack, new_dist Dist, op string) Stack { + + var combined_dist Dist + var err error + switch op { + case "*": + if combined_dist, err = multiplyDists(stack.old_dist, new_dist); err == nil { + stack.old_dist = combined_dist + } + case "/": + if combined_dist, err = divideDists(stack.old_dist, new_dist); err == nil { + stack.old_dist = combined_dist + } + case "+": + if combined_dist, err = operateDistsAsSamples(stack.old_dist, new_dist, "+"); err == nil { + stack.old_dist = combined_dist + } + case "-": + if combined_dist, err = operateDistsAsSamples(stack.old_dist, new_dist, "-"); err == nil { + stack.old_dist = combined_dist + } + default: + fmt.Println("Can't combine distributions in this way") + } + return stack -type Stack struct { - old_dist Dist - vars map[string]Dist } func combineStackAndNewLine(stack Stack, new_line string) Stack { @@ -351,67 +395,58 @@ func combineStackAndNewLine(stack Stack, new_line string) Stack { return stack } - { - words := strings.Split(strings.TrimSpace(new_line), " ") - switch { - case words[0] == "exit" || words[0] == "e": - os.Exit(0) - case words[0] == "help" || words[0] == "h": - fmt.Println(GENERAL_ERR_MSG) - return stack - case words[0] == "debug" || words[0] == "d": - fmt.Printf("Old dist: %v\n", stack.old_dist) - fmt.Printf("Vars: %v\n", stack.vars) - return stack - case words[0] == "=:" && len(words) == 2: - stack.vars[words[1]] = stack.old_dist - fmt.Printf("%s ", words[1]) - prettyPrintDist(stack.old_dist) - return stack - case words[0] == "." || words[0] == "clean" || words[0] == "c": - stack.old_dist = init_dist - fmt.Println() - return stack - case words[0] == "=." && len(words) == 2: - stack.vars[words[1]] = stack.old_dist - fmt.Printf("%s ", words[1]) - prettyPrintDist(stack.old_dist) - stack.old_dist = init_dist - fmt.Println() - return stack - // Other possible cases: - // Save to file - // Sample n samples - // Save stack to a variable? - // clean stack - // Define a function? No, too much of a nerdsnipea - } - } - - op, new_dist, err := parseLine(new_line, stack.vars) - if err != nil { + // Various stack manipulations that don't involve distributions + words := strings.Split(strings.TrimSpace(new_line), " ") + switch { + case words[0] == "exit" || words[0] == "e": + os.Exit(0) + case words[0] == "help" || words[0] == "h": + fmt.Println(GENERAL_ERR_MSG) return stack - } - - joint_dist, err := joinDists(stack.old_dist, new_dist, op) - if err != nil { - fmt.Printf("%v\n", err) - fmt.Printf("Dist on stack: ") + case words[0] == "debug" || words[0] == "d": + fmt.Printf("Old dist: %v\n", stack.old_dist) + fmt.Printf("Vars: %v\n", stack.vars) + return stack + case words[0] == "=:" && len(words) == 2: + stack.vars[words[1]] = stack.old_dist + fmt.Printf("%s ", words[1]) prettyPrintDist(stack.old_dist) return stack + case words[0] == "." || words[0] == "clear" || words[0] == "c": + stack.old_dist = INIT_DIST + fmt.Println() + return stack + case words[0] == "=." && len(words) == 2: + stack.vars[words[1]] = stack.old_dist + fmt.Printf("%s ", words[1]) + prettyPrintDist(stack.old_dist) + stack.old_dist = INIT_DIST + fmt.Println() + return stack + // Other possible cases: save to file, sample n samples, save stack to a variable, clear stack, define a function } - stack.old_dist = joint_dist + + op, new_dist, err := parseLineIntoOpAndDist(new_line, stack.vars) + if err != nil { + return stack + } + stack = combineStackAndDist(stack, new_dist, op) prettyPrintDist(stack.old_dist) return stack } +func runRepl(stack Stack, reader *bufio.Reader) Stack { + + for { + new_line, _ := reader.ReadString('\n') + stack = combineStackAndNewLine(stack, new_line) + } +} + /* Main event loop */ func main() { reader := bufio.NewReader(os.Stdin) - stack := Stack{old_dist: init_dist, vars: make(map[string]Dist)} - for { - new_line, _ := reader.ReadString('\n') - stack = combineStackAndNewLine(stack, new_line) - } + stack := Stack{old_dist: INIT_DIST, vars: make(map[string]Dist)} + runRepl(stack, reader) }