simplify suggestions ordering

This commit is contained in:
Joeri Exelmans 2025-05-20 16:53:04 +02:00
parent fdbf43a4e9
commit bb6e742f5f
8 changed files with 109 additions and 110 deletions

View file

@ -2,8 +2,10 @@ import { useEffect, useState } from 'react';
import './App.css';
import { ExprBlock, type ExprBlockState } from './ExprBlock';
import { GlobalContext } from './GlobalContext';
import { biggerExample, higherOrder, higherOrder2Params, inc, initialEditorState, lambda2Params, nonEmptyEditorState, pushBool, tripleFunctionCallEditorState } from "./configurations";
import { biggerExample, emptySet, higherOrder, higherOrder2Params, inc, initialEditorState, lambda2Params, nonEmptyEditorState, pushBool, tripleFunctionCallEditorState } from "./configurations";
import { actionShortcuts } from './actions';
import { scoreResolved, type ResolvedType } from './eval';
import type { InputBlockState } from './InputBlock';
const examples: [string, ExprBlockState][] = [
@ -16,6 +18,7 @@ const examples: [string, ExprBlockState][] = [
["higher order 2" , higherOrder2Params ],
["push Bool" , pushBool ],
["inc" , inc ],
["empty set" , emptySet ],
];
type AppState = {
@ -163,9 +166,8 @@ export function App() {
state={appState.history.at(-1)!}
setState={pushHistory}
onCancel={() => {}}
suggestionPriority={() => {
// console.log('suggestionPriority of App, always 0');
return 0;
score={(resolved: ResolvedType) => {
return scoreResolved(resolved, () => 0);
}}
/>
</GlobalContext>

View file

@ -1,15 +1,14 @@
import { useContext } from "react";
import { ExprBlock, type ExprBlockState, type SetStateFn, type State2Props } from "./ExprBlock";
import { EnvContext } from "./EnvContext";
import { addFocusRightMost, evalCallBlock2, evalEditorBlock, removeFocus, scoreResolved, type ResolvedType } from "./eval";
import { addFocusRightMost, evalCallBlock2, evalExprBlock, recomputeTypeVarsForEnv, scoreResolved, type Environment, type ResolvedType } from "./eval";
import { ExprBlock, type ExprBlockState, type SetStateFn, type State2Props } from "./ExprBlock";
import { GlobalContext } from "./GlobalContext";
import { Value } from "./Value";
import "./CallBlock.css";
import { initialEditorState } from "./configurations";
import { CallContext } from "./CallContext";
import { getActions } from "./actions";
import "./CallBlock.css";
import { CallContext } from "./CallContext";
export interface CallBlockState {
kind: "call";
@ -17,48 +16,61 @@ export interface CallBlockState {
input: ExprBlockState;
}
interface CallBlockProps<
export interface CallBlockProps<
FnState=ExprBlockState,
InputState=ExprBlockState,
> extends State2Props<CallBlockState,ExprBlockState> {}
function nestedFnProperties({state, setState, suggestionPriority}: CallBlockProps, env) {
function nestedFnProperties({state, setState, score}: CallBlockProps, env) {
const setFn = (callback: SetStateFn) => {
setState(state => ({...state, fn: callback(state.fn)}));
}
const onFnCancel = () => {
setState(state => state.input); // we become our input
}
const fnSuggestionPriority = (fnSuggestion: ResolvedType) => computePriority(
const scoreFn = (fnSuggestion: ResolvedType) => {
return computePriority(
fnSuggestion,
evalEditorBlock(state.input, env)[0],
suggestionPriority,
evalExprBlock(state.input, env)[0],
score,
env,
);
return {state: state.fn, setState: setFn, onCancel: onFnCancel, suggestionPriority: fnSuggestionPriority};
};
return {state: state.fn, setState: setFn, onCancel: onFnCancel, score: scoreFn};
}
function nestedInputProperties({state, setState, suggestionPriority}: CallBlockProps, env) {
function nestedInputProperties({state, setState, score}: CallBlockProps, env: Environment) {
const setInput = (callback: SetStateFn) => {
setState(state => ({...state, input: callback(state.input)}));
}
const onInputCancel = () => {
setState(state => addFocusRightMost(state.fn)); // we become our function
}
const inputSuggestionPriorirty = (inputSuggestion: ResolvedType) => computePriority(
evalEditorBlock(state.fn, env)[0], // fn *may* be set
inputSuggestion, // suggestions will be for input
suggestionPriority, // priority function we get from parent block
env,
)
return {state: state.input, setState: setInput, onCancel: onInputCancel, suggestionPriority: inputSuggestionPriorirty};
const scoreInput = (inputSuggestion: ResolvedType) => {
return computePriority(
evalExprBlock(state.fn, env)[0], // fn *may* be set
inputSuggestion, // suggestions will be for input
score, // priority function we get from parent block
env,
);
}
return {state: state.input, setState: setInput, onCancel: onInputCancel, score: scoreInput};
}
function computePriority(fn: ResolvedType, input: ResolvedType, outPriority: (s: ResolvedType) => number, env) {
// dirty, but works:
const [fnR, env2] = recomputeTypeVarsForEnv('<fn>', fn, env);
const [inR, env3] = recomputeTypeVarsForEnv('<in>', input, env2);
const [resolved] = evalCallBlock2(fnR, inR, env3);
const score = scoreResolved(resolved, outPriority);
return score;
}
export function CallBlock(props: CallBlockProps) {
const env = useContext(EnvContext);
const globalContext = useContext(GlobalContext);
const addParam = getActions(globalContext, props.setState).c;
const [resolved] = evalEditorBlock(props.state, env);
const [resolved] = evalExprBlock(props.state, env);
return <span className={"functionBlock" + ((resolved.kind === "error") ? " unifyError" : "")}>
<CallContext value={{addParam}}>
<FunctionHeader {...props} addParam={addParam} />
@ -80,12 +92,6 @@ export function CallBlock(props: CallBlockProps) {
</span>;
}
function computePriority(fn: ResolvedType, input: ResolvedType, outPriority: (s: ResolvedType) => number, env) {
const [resolved] = evalCallBlock2(fn, input, env);
const score = scoreResolved(resolved, outPriority);
return score;
}
function FunctionHeader(props) {
const env = useContext(EnvContext);
const globalContext = useContext(GlobalContext);

View file

@ -2,14 +2,14 @@ import { useContext } from "react";
import { getType } from "dope2";
import { CallBlock, type CallBlockState } from "./CallBlock";
import { CallBlock, type CallBlockProps, type CallBlockState } from "./CallBlock";
import { EnvContext } from "./EnvContext";
import { GlobalContext } from "./GlobalContext";
import { InputBlock, type InputBlockState } from "./InputBlock";
import { LambdaBlock, type LambdaBlockState } from "./LambdaBlock";
import { LetInBlock, type LetInBlockState } from "./LetInBlock";
import { InputBlock, type InputBlockProps, type InputBlockState } from "./InputBlock";
import { LambdaBlock, type LambdaBlockProps, type LambdaBlockState } from "./LambdaBlock";
import { LetInBlock, type LetInBlockProps, type LetInBlockState } from "./LetInBlock";
import { Type } from "./Type";
import { evalEditorBlock, type ResolvedType } from "./eval";
import { evalExprBlock, type ResolvedType } from "./eval";
import "./ExprBlock.css";
import { Input } from "./Input";
@ -26,48 +26,31 @@ export type SetStateFn<InType = ExprBlockState, OutType = InType> = (state: InTy
export interface State2Props<InType, OutType = InType> {
state: InType;
setState: (callback: SetStateFn<InType, OutType>) => void;
suggestionPriority: (suggestion: ResolvedType) => number;
score: (suggestion: ResolvedType) => number;
}
interface ExprBlockProps extends State2Props<ExprBlockState> {
onCancel: () => void;
}
export function ExprBlock({state, setState, suggestionPriority, onCancel}: ExprBlockProps) {
export function ExprBlock(props: ExprBlockProps) {
const env = useContext(EnvContext);
const globalContext = useContext(GlobalContext);
const renderBlock = {
input: () => <InputBlock
state={state as InputBlockState}
setState={setState as (callback:(p:InputBlockState)=>ExprBlockState)=>void}
suggestionPriority={suggestionPriority}
onCancel={onCancel}
/>,
call: () => <CallBlock
state={state as CallBlockState}
setState={setState as (callback:(p:CallBlockState)=>ExprBlockState)=>void}
suggestionPriority={suggestionPriority}
/>,
let: () => <LetInBlock
state={state as LetInBlockState}
setState={setState as (callback:(p:LetInBlockState)=>ExprBlockState)=>void}
suggestionPriority={suggestionPriority}
/>,
lambda: () => <LambdaBlock
state={state as LambdaBlockState}
setState={setState as (callback:(p:LambdaBlockState)=>ExprBlockState)=>void}
suggestionPriority={suggestionPriority}
/>,
input: () => <InputBlock {...props as InputBlockProps} />,
call: () => <CallBlock {...props as CallBlockProps} />,
let: () => <LetInBlock {...props as LetInBlockProps} />,
lambda: () => <LambdaBlock {...props as LambdaBlockProps} />,
};
const [resolved] = evalEditorBlock(state, env);
const actions = getActions(globalContext, setState);
const [resolved] = evalExprBlock(props.state, env);
const actions = getActions(globalContext, props.setState);
const extraHandlers = Object.fromEntries(Object.entries(actions).map(([shortcut, action]) =>
[shortcut, (e) => { e.preventDefault(); action(); }]))
return <span className={"editor" + ((resolved.kind!=="value") ? " "+resolved.kind : "")}>
{renderBlock[state.kind]()}
{renderBlock[props.state.kind]()}
<div className="typeSignature">
&nbsp;::&nbsp;<Type type={getType(resolved)} />
</div>
@ -76,7 +59,7 @@ export function ExprBlock({state, setState, suggestionPriority, onCancel}: ExprB
text=""
suggestion=""
onEnter={() => {}}
onCancel={onCancel}
onCancel={props.onCancel}
onTextChange={() => {}}
extraHandlers={extraHandlers}
/>

View file

@ -3,13 +3,12 @@ import { memo, useContext, useEffect, useMemo, useRef, useState } from "react";
import { getType, prettyT, trie } from "dope2";
import { EnvContext } from "./EnvContext";
import type { Dynamic, ResolvedType } from "./eval";
import type { Environment, ResolvedType } from "./eval";
import "./InputBlock.css";
import { Type } from "./Type";
import type { ExprBlockState, State2Props } from "./ExprBlock";
import { attemptParseLiteral } from "./eval";
import { Input } from "./Input";
import { initialEditorState } from "./configurations";
import { CallContext } from "./CallContext";
import { getActions } from "./actions";
import { GlobalContext } from "./GlobalContext";
@ -33,37 +32,35 @@ export interface InputBlockState {
focus: boolean
}
export type SuggestionType = ['literal'|'name', string, Dynamic];
export type SuggestionType = ["literal"|"name", string, ResolvedType];
export type PrioritizedSuggestionType = [number, ...SuggestionType];
interface InputBlockProps extends State2Props<InputBlockState,ExprBlockState> {
export interface InputBlockProps extends State2Props<InputBlockState,ExprBlockState> {
onCancel: () => void;
}
const computeSuggestions = (text, env, suggestionPriority: (s: ResolvedType) => number): PrioritizedSuggestionType[] => {
const computeSuggestions = (
text: string,
env: Environment,
score: InputBlockProps['score'],
): PrioritizedSuggestionType[] => {
const literals = attemptParseLiteral(text, env);
const ls: SuggestionType[] = [
// literals
... literals.map((lit) => ["literal", text, lit]),
... literals.map((resolved) => ["literal", text, resolved]),
// names
... trie.suggest(env.names)(text)(Infinity)
.map(([name,type]) => [
"name",
name, {
...type,
substitutions: type.substitutions || new Map(),
kind: type.kind || "value",
}]),
.map(([name, resolved]) => ["name", name, resolved]),
]
// return []; // <-- uncomment to disable suggestions (useful for debugging)
return ls
.map((suggestion) => [suggestionPriority(suggestion[2]), ...suggestion] as PrioritizedSuggestionType)
.map((suggestion: SuggestionType) =>
[score(suggestion[2]), ...suggestion] as PrioritizedSuggestionType)
.sort(([priorityA], [priorityB]) => priorityB - priorityA)
}
export function InputBlock({ state, setState, suggestionPriority, onCancel }: InputBlockProps) {
export function InputBlock({ state, setState, score, onCancel }: InputBlockProps) {
const {text, focus} = state;
const globalContext = useContext(GlobalContext);
const env = useContext(EnvContext);
@ -72,7 +69,7 @@ export function InputBlock({ state, setState, suggestionPriority, onCancel }: In
const [i, setI] = useState(0); // selected suggestion idx
const singleSuggestion = trie.growPrefix(env.names)(text);
const suggestions = useMemo(() => computeSuggestions(text, env, suggestionPriority), [text, suggestionPriority, env]);
const suggestions = useMemo(() => computeSuggestions(text, env, score), [text, score, env]);
useEffect(() => {
@ -176,20 +173,20 @@ interface SuggestionProps {
suggestion: PrioritizedSuggestionType;
}
function Suggestion({ setI, j, onSelect, highlighted, suggestion: [priority, kind, name, dynamic] }: SuggestionProps) {
function Suggestion({ setI, j, onSelect, highlighted, suggestion: [priority, kind, text, resolved] }: SuggestionProps) {
const onMouseEnter = j => () => {
setI(j);
};
const onMouseDown = j => () => {
setI(j);
onSelect([priority, kind, name, dynamic]);
onSelect();
};
return <div
key={`${j}_${name}`}
className={(highlighted ? " selected" : "")}
onMouseEnter={onMouseEnter(j)}
onMouseDown={onMouseDown(j)}>
({priority}) ({kind}) {name} :: <Type type={getType(dynamic)} />
({priority}) ({kind}) {text} :: <Type type={resolved.t} />
</div>
}

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@ -4,7 +4,7 @@ import { eqType, getSymbol, reduceUnification } from "dope2";
import { ExprBlock, type ExprBlockState, type State2Props } from "./ExprBlock";
import { EnvContext } from "./EnvContext";
import { evalEditorBlock, makeInnerEnv, makeTypeVar } from "./eval";
import { evalExprBlock, makeInnerEnv, makeTypeVar } from "./eval";
import "./LambdaBlock.css";
import { Type } from "./Type";
@ -17,14 +17,14 @@ export interface LambdaBlockState {
expr: ExprBlockState;
}
interface LambdaBlockProps<
export interface LambdaBlockProps<
FnState=ExprBlockState,
InputState=ExprBlockState,
> extends State2Props<LambdaBlockState,ExprBlockState> {
}
export function LambdaBlock({state, setState, suggestionPriority}: LambdaBlockProps) {
export function LambdaBlock({state, setState, score}: LambdaBlockProps) {
const env = useContext(EnvContext);
const setParamName = paramName => setState(state => ({
@ -38,7 +38,7 @@ export function LambdaBlock({state, setState, suggestionPriority}: LambdaBlockPr
const [paramType, staticInnerEnv] = makeTypeVar(env, state.paramName);
const [exprResolved] = evalEditorBlock(state.expr, staticInnerEnv);
const [exprResolved] = evalExprBlock(state.expr, staticInnerEnv);
const inferredParamType = reduceUnification(exprResolved.unification).get(getSymbol(paramType)) || paramType;
@ -76,9 +76,9 @@ export function LambdaBlock({state, setState, suggestionPriority}: LambdaBlockPr
state={state.expr}
setState={setExpr}
onCancel={() => setState(state => state.expr)}
suggestionPriority={(s) => {
score={(s) => {
// console.log('suggestionPriority of lambdaInner... just passing through');
return suggestionPriority(s);
return score(s);
}}
/>
</EnvContext>

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@ -2,7 +2,7 @@ import { useContext } from "react";
import { ExprBlock, type ExprBlockState } from "./ExprBlock";
import { EnvContext } from "./EnvContext";
import { evalEditorBlock, makeInnerEnv, scoreResolved, type ResolvedType } from "./eval";
import { evalExprBlock, makeInnerEnv, scoreResolved, type ResolvedType } from "./eval";
import { type State2Props } from "./ExprBlock";
import { GlobalContext } from "./GlobalContext";
@ -17,7 +17,7 @@ export interface LetInBlockState {
inner: ExprBlockState;
}
interface LetInBlockProps extends State2Props<LetInBlockState,ExprBlockState> {
export interface LetInBlockProps extends State2Props<LetInBlockState,ExprBlockState> {
}
export function LetInBlock(props: LetInBlockProps) {
@ -31,7 +31,7 @@ export function LetInBlock(props: LetInBlockProps) {
</span>
}
function DeclColumns({state: {name, value, inner, focus}, setState, suggestionPriority}) {
function DeclColumns({state: {name, value, inner, focus}, setState, score}) {
const env = useContext(EnvContext);
const globalContext = useContext(GlobalContext);
@ -40,11 +40,11 @@ function DeclColumns({state: {name, value, inner, focus}, setState, suggestionPr
const valueSuggestionPriority = (suggestion: ResolvedType) => {
const innerEnv = makeInnerEnv(env, name, suggestion);
const [resolved] = evalEditorBlock(inner, innerEnv);
return scoreResolved(resolved, suggestionPriority);
const [resolved] = evalExprBlock(inner, innerEnv);
return scoreResolved(resolved, score);
};
const [valueResolved] = evalEditorBlock(value, env);
const [valueResolved] = evalExprBlock(value, env);
const innerEnv = makeInnerEnv(env, name, valueResolved);
return <>
@ -65,7 +65,7 @@ function DeclColumns({state: {name, value, inner, focus}, setState, suggestionPr
<ExprBlock
state={value}
setState={setValue}
suggestionPriority={valueSuggestionPriority}
score={valueSuggestionPriority}
onCancel={() => setState(state => state.inner)} // keep inner
/>
</span>
@ -75,18 +75,18 @@ function DeclColumns({state: {name, value, inner, focus}, setState, suggestionPr
<DeclColumns
state={inner}
setState={setInner}
suggestionPriority={suggestionPriority}
score={score}
/>
</EnvContext>
}
</>;
}
function InnerMost({state, setState, suggestionPriority}) {
function InnerMost({state, setState, score}) {
const env = useContext(EnvContext);
const globalContext = useContext(GlobalContext);
const setInner = callback => setState(state => ({...state, inner: callback(state.inner)}));
const [valueResolved] = evalEditorBlock(state.value, env);
const [valueResolved] = evalExprBlock(state.value, env);
const innerEnv = makeInnerEnv(env, state.name, valueResolved);
const onCancel = () => setState(state => state.value);
if (state.inner.kind === "let" && globalContext?.syntacticSugar) {
@ -94,7 +94,7 @@ function InnerMost({state, setState, suggestionPriority}) {
<InnerMost
state={state.inner}
setState={setInner}
suggestionPriority={suggestionPriority}
score={score}
/>
</EnvContext>;
}
@ -103,7 +103,7 @@ function InnerMost({state, setState, suggestionPriority}) {
<ExprBlock
state={state.inner}
setState={setInner}
suggestionPriority={suggestionPriority}
score={score}
onCancel={onCancel} // keep value
/>
</EnvContext>

View file

@ -138,3 +138,5 @@ export const higherOrder2Params: ExprBlockState = {"kind":"let","focus":false,"i
export const pushBool: ExprBlockState = {"kind":"call","fn":{"kind":"call","fn":{"kind":"input","text":"list.push","value":{"kind":"name"},"focus":false},"input":{"kind":"input","text":"list.emptyList","value":{"kind":"name"},"focus":false}},"input":{"kind":"input","text":"Bool","value":{"kind":"name"},"focus":true}};
export const inc: ExprBlockState = {"kind":"let","focus":false,"inner":{"kind":"input","text":"","value":{"kind":"name"},"focus":false},"name":"inc","value":{"kind":"lambda","focus":false,"paramName":"x","expr":{"kind":"call","fn":{"kind":"call","fn":{"kind":"input","text":"addInt","value":{"kind":"name"},"focus":false},"input":{"kind":"input","text":"x","value":{"kind":"name"},"focus":false}},"input":{"kind":"input","text":"1","value":{"kind":"literal","type":"Int"},"focus":true}}}};
export const emptySet: ExprBlockState = {"kind":"call","fn":{"kind":"input","text":"set.emptySet","value":{"kind":"name"},"focus":false},"input":{"kind":"input","text":"","value":{"kind":"text"},"focus":true}};

View file

@ -4,7 +4,7 @@ import type { ExprBlockState } from "./ExprBlock";
import type { InputValueType } from "./InputBlock";
const IS_DEV = (import.meta.env.MODE === "development");
const VERBOSE = false;
const VERBOSE = true;
export interface Environment {
names: any;
@ -46,7 +46,7 @@ export type ResolvedType = Dynamic | DeepError | Unknown;
class NotFoundError extends Error {}
export const evalEditorBlock = (s: ExprBlockState, env: Environment): [ResolvedType,Environment] => {
export const evalExprBlock = (s: ExprBlockState, env: Environment): [ResolvedType,Environment] => {
if (s.kind === "input") {
return evalInputBlock(s.text, s.value, env);
}
@ -88,8 +88,8 @@ export function evalInputBlock(text: string, value: InputValueType, env: Environ
}
export function evalCallBlock(fn: ExprBlockState, input: ExprBlockState, env: Environment): [ResolvedType,Environment] {
const [fnResolved, env2] = evalEditorBlock(fn, env);
const [inputResolved, env3] = evalEditorBlock(input, env2);
const [fnResolved, env2] = evalExprBlock(fn, env);
const [inputResolved, env3] = evalExprBlock(input, env2);
if (VERBOSE) {
console.log('==== evalCallBlock ====');
console.log('env :', env);
@ -103,6 +103,9 @@ export function evalCallBlock(fn: ExprBlockState, input: ExprBlockState, env: En
}
export function evalCallBlock2(fnResolved: ResolvedType, inputResolved: ResolvedType, env: Environment): [ResolvedType,Environment] {
if (occurring(fnResolved.t).intersection(occurring(inputResolved.t)).size > 0) {
throw new Error(`Precondition failed: function (${prettyT(fnResolved.t)}) and its input (${prettyT(inputResolved.t)}) have overlapping typevars!`);
}
if (getSymbol(fnResolved.t) !== symbolFunction) {
// not a function...
if (isTypeVar(fnResolved.t)) {
@ -143,7 +146,7 @@ const inverseUnification = (uni, inverse) => {
);
}
function recomputeTypeVarsForEnv(name: string, resolved: ResolvedType, env: Environment): [ResolvedType,Environment] {
export function recomputeTypeVarsForEnv(name: string, resolved: ResolvedType, env: Environment): [ResolvedType,Environment] {
const [[newType], inverse] = recomputeTypeVarsWithInverse([resolved.t], env.nextFreeTypeVar);
const newResolved: ResolvedType = {
...resolved,
@ -281,9 +284,9 @@ function evalCallBlock3(fnResolved: ResolvedType, inputResolved: ResolvedType, e
}
export function evalLetInBlock(value: ExprBlockState, name: string, inner: ExprBlockState, env: Environment): [ResolvedType,Environment] {
const [valueResolved] = evalEditorBlock(value, env);
const [valueResolved] = evalExprBlock(value, env);
const innerEnv = makeInnerEnv(env, name, valueResolved);
return evalEditorBlock(inner, innerEnv);
return evalExprBlock(inner, innerEnv);
}
const prettyRU = (rUni: Map<string, Type>) => {
@ -301,7 +304,7 @@ export function evalLambdaBlock(paramName: string, expr: ExprBlockState, env: En
console.log('===================================')
}
const [exprResolved] = evalEditorBlock(expr, staticInnerEnv);
const [exprResolved] = evalExprBlock(expr, staticInnerEnv);
const lambdaT = fnType(_ => paramType)(_ => exprResolved.t);
// This is the only place in the code where we actually do something with the 'substitutions'. We compute the type of our lambda function:
const reduced = reduceUnification(exprResolved.unification);
@ -331,7 +334,7 @@ export function evalLambdaBlock(paramName: string, expr: ExprBlockState, env: En
t: paramTypeSubstituted,
unification: new Map(),
});
const [result] = evalEditorBlock(expr, innerEnv);
const [result] = evalExprBlock(expr, innerEnv);
if (result.kind === "value") {
return result.i;
}
@ -411,16 +414,22 @@ export function attemptParseLiteral(text: string, env: Environment): Dynamic[] {
export function scoreResolved(resolved: ResolvedType, outPriority: (s:ResolvedType) => number) {
const bias = outPriority(resolved);
console.log('scoreResolved...', resolved);
if (resolved.kind === "value") {
console.log('best:', 2, bias);
return 2 + bias;
}
else if (resolved.kind === "unknown") {
console.log('ok:', 1, bias);
return 1 + bias;
}
if (resolved.e instanceof UnifyError) {
console.log('bad:', -1, bias);
return -1 + bias; // parameter doesn't match
}
else {
console.log('worst:', -2, bias);
return -2 + bias; // even worse: fn is not a function!
}
}