Yichus Playground

Reference

SimConfig

Top-level configuration binding. Must be named config.

Field	Type	Description
name	String	Display title
description	String	Subtitle text
package_name	String	Must match computation package
function_name	String	Entry function to call
inputs	List[(String, InputConfig)]	Named input controls
outputs	List[(String, OutputConfig)]	Named output displays
assumptions	List[AssumptionConfig]	What-if toggles (or `[]`)
sweeps	List[SweepConfig]	Parameter sweep charts (or `[]`)
snippet_max_lines	Int	Why snippet limit (`0` = disabled)

Widget (enum)

Slider NumberInput

InputConfig

Field	Type	Description
label	String	Display label
default_value	Int	Initial value
min_value	Int	Minimum bound
max_value	Int	Maximum bound
step	Int	Step increment
widget	Widget	`Slider` or `NumberInput`

OutputFormat (enum)

Currency Percent Number

OutputConfig

Field	Type	Description
label	String	Display label
format	OutputFormat	How to format the value
primary	Bool	`True` = highlighted output

ChartType (enum)

Line Area Bar

SweepConfig

Field	Type	Description
input_param	String	Input name to sweep
min_value	Int	Sweep start
max_value	Int	Sweep end
steps	Int	Number of data points
output_param	String	Output name to plot
chart_type	ChartType	`Line`, `Area`, or `Bar`

AssumptionConfig

Field	Type	Description
name	String	Toggle label
description	String	Help text
variants	List[(String, String)]	(label, function_suffix) pairs

Quick Example

config = SimConfig(
  "My Sim", "Description",
  "MyPackage", "calculate",
  [("x", InputConfig("X", 50, 0, 100, 1, Slider))],
  [("y", OutputConfig("Result", Currency, True))],
  [], [], 0
)

Import Line

from Yichus/Simulation import (
  InputConfig, OutputConfig,
  AssumptionConfig, SweepConfig, SimConfig,
  Slider, NumberInput,
  Currency, Percent, Number,
  Line, Area, Bar
)

Packages & Imports

package MyPackage

from Bosatsu/Predef import Int, String, Bool, List
from Bosatsu/Numeric import Double, from_Int

Each file starts with package Name. Use from Pkg import ... to bring names into scope.

Types

Type	Notes
Int	Arbitrary-precision integer
String	Text value
Bool	`True` or `False`
List[A]	Linked list, e.g. `[1, 2, 3]`
(A, B)	Tuple, e.g. `("key", 42)`
Double	Floating point (from `Bosatsu/Numeric`)

Structs

struct Point(x: Int, y: Int)

p = Point(3, 4)
# Access fields via pattern matching

Functions

def add(a: Int, b: Int) -> Int:
  a.add(b)

def greet(name: String) -> String:
  "Hello, ".concat(name)

Functions use indentation for body. Type annotations are required on parameters and return type.

Pattern Matching

match point:
  case Point(x, y):
    x.add(y)

Exhaustive matching is required. Use _ for wildcard.

Enums

enum Color: Red, Green, Blue

match c:
  case Red: "red"
  case Green: "green"
  case Blue: "blue"

Constructors are bare names imported directly.

Let Bindings

def calc(x: Int) -> Int:
  doubled = x.times(2)
  offset = doubled.add(10)
  offset

Bindings are name = expr. The last expression is the return value.

Common Predef Functions

Function	Signature
add	Int -> Int -> Int
sub	Int -> Int -> Int
times	Int -> Int -> Int
div	Int -> Int -> Int
mod_Int	Int -> Int -> Int
eq_Int	Int -> Int -> Bool
cmp_Int	Int -> Int -> Comparison
int_to_String	Int -> String
concat_String	String -> String -> String

Bosatsu/Numeric (Double)

from Bosatsu/Numeric import (
  Double, from_Int,
  add_Double, sub_Double,
  mul_Double, div_Double
)

Function	Signature
from_Int	Int -> Double
add_Double	Double -> Double -> Double
sub_Double	Double -> Double -> Double
mul_Double	Double -> Double -> Double
div_Double	Double -> Double -> Double

Tips

All values are immutable. No loops -- use recursion or foldLeft.

Integer math only by default. Use from_Int to convert to Double for fractional arithmetic.

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