hitting spacebar always adds a parameter to the first ancestor that is a CallBlock

src/App.tsx

@@ -1,10 +1,9 @@
 import { useEffect, useState } from 'react';
 import './App.css';
-import { GlobalContext } from './GlobalContext';
 import { ExprBlock, type ExprBlockState } from './ExprBlock';
-import { extendedEnv } from './EnvContext';
+import { GlobalContext } from './GlobalContext';
 import { biggerExample, higherOrder, higherOrder2Params, inc, initialEditorState, lambda2Params, nonEmptyEditorState, pushBool, tripleFunctionCallEditorState } from "./configurations";
-import { evalEditorBlock } from "./eval";
+import { removeFocus } from "./eval";
 
 const commands: [string, string[], string][] = [
   ["call"     , ['c'              ], "call"          ],
@@ -174,6 +173,14 @@ export function App() {
               // console.log('suggestionPriority of App, always 0');
               return 0;
             }}
+            addParam={(s: ExprBlockState) => {
+              pushHistory(state => ({
+                kind: "call",
+                fn: removeFocus(state),
+                input: initialEditorState,
+              }));
+              doHighlight.call();
+            }}
           />
         </GlobalContext>
 

src/CallBlock.tsx

@@ -2,11 +2,12 @@ import { useContext } from "react";
 
 import { ExprBlock, type ExprBlockState, type SetStateFn, type State2Props } from "./ExprBlock";
 import { EnvContext } from "./EnvContext";
-import { evalCallBlock2, evalEditorBlock, scoreResolved, type ResolvedType } from "./eval";
+import { addFocusRightMost, evalCallBlock2, evalEditorBlock, removeFocus, scoreResolved, type ResolvedType } from "./eval";
 import { GlobalContext } from "./GlobalContext";
 import { Value } from "./Value";
 
 import "./CallBlock.css";
+import { initialEditorState } from "./configurations";
 
 export interface CallBlockState {
   kind: "call";
@@ -40,7 +41,7 @@ function nestedInputProperties({state, setState, suggestionPriority}: CallBlockP
     setState(state => ({...state, input: callback(state.input)}));
   }
   const onInputCancel = () => {
-    setState(state => state.fn); // we become our function
+    setState(state => addFocusRightMost(state.fn)); // we become our function
   }
   const inputSuggestionPriorirty = (inputSuggestion: ResolvedType) => computePriority(
     evalEditorBlock(state.fn, env)[0], // fn *may* be set
@@ -53,9 +54,18 @@ function nestedInputProperties({state, setState, suggestionPriority}: CallBlockP
 
 export function CallBlock(props: CallBlockProps) {
   const env = useContext(EnvContext);
+  const globalContext = useContext(GlobalContext);
+  const addParam = (s: ExprBlockState) => {
+    props.setState(state => ({
+      kind: "call",
+      fn: removeFocus(state),
+      input: s,
+    }));
+    globalContext?.doHighlight.call();
+  };
   const [resolved] = evalEditorBlock(props.state, env);
   return <span className={"functionBlock" + ((resolved.kind === "error") ? " unifyError" : "")}>
-    <FunctionHeader {...props} />
+    <FunctionHeader {...props} addParam={addParam} />
     <div className="functionParams">
       <div className="outputParam">
         {/* Sequence of input parameters */}
@@ -63,6 +73,7 @@ export function CallBlock(props: CallBlockProps) {
           {...props}
           depth={0}
           errorDepth={(resolved.kind === "error") ? (resolved.depth) : -1}
+          addParam={addParam}
           />
         {  (resolved.kind === "error") && resolved.e.toString()
         || (resolved.kind === "value") && <Value dynamic={resolved} />
@@ -91,12 +102,12 @@ function FunctionHeader(props) {
     //  end of recursion - draw function name
     return <span className="functionName">
       &nbsp;&#119891;&#119899;&nbsp;
-      <ExprBlock {...nestedProperties} />
+      <ExprBlock {...nestedProperties} addParam={props.addParam} />
     </span>;
   }
 }
 
-function InputParams({ depth, errorDepth, ...rest }) {
+function InputParams({ depth, errorDepth, addParam, ...rest }) {
   const env = useContext(EnvContext);
   const globalContext = useContext(GlobalContext);
   const isOffending = depth === errorDepth;
@@ -107,10 +118,12 @@ function InputParams({ depth, errorDepth, ...rest }) {
         {...nestedFnProperties(rest as CallBlockProps, env)}
         depth={depth+1}
         errorDepth={errorDepth}
+        addParam={addParam}
         />}
     {/* Our own input param */}
     <ExprBlock
       {...nestedInputProperties(rest as CallBlockProps, env)}
+      addParam={addParam}
       />
   </div>;
 }

src/ExprBlock.tsx

@@ -10,7 +10,7 @@ import { LambdaBlock, type LambdaBlockState } from "./LambdaBlock";
 import { LetInBlock, type LetInBlockState } from "./LetInBlock";
 import { Type } from "./Type";
 import { initialEditorState } from "./configurations";
-import { evalEditorBlock, type ResolvedType } from "./eval";
+import { evalEditorBlock, removeFocus, type ResolvedType } from "./eval";
 import { focusNextElement, focusPrevElement } from "./util/dom_trickery";
 
 import "./ExprBlock.css";
@@ -31,6 +31,7 @@ export interface State2Props<InType, OutType = InType> {
 
 interface ExprBlockProps extends State2Props<ExprBlockState> {
   onCancel: () => void;
+  addParam: (e: ExprBlockState) => void;
 }
 
 function getCommands(type) {
@@ -47,20 +48,7 @@ function getShortCommands(type) {
   return 'Tab|.';
 }
 
-function removeFocus(state: ExprBlockState): ExprBlockState {
+export function ExprBlock({state, setState, suggestionPriority, onCancel, addParam}: ExprBlockProps) {
-  if (state.kind === "input") {
-    return {...state, focus: false};
-  }
-  if (state.kind === "call") {
-    return {...state,
-      fn: removeFocus(state.fn),
-      input: removeFocus(state.input),
-    };
-  }
-  return state;
-}
-
-export function ExprBlock({state, setState, onCancel, suggestionPriority}: ExprBlockProps) {
   const env = useContext(EnvContext);
   const [needCommand, setNeedCommand] = useState(false);
   const commandInputRef = useRef<HTMLInputElement>(null);
@@ -95,7 +83,6 @@ export function ExprBlock({state, setState, onCancel, suggestionPriority}: ExprB
         kind: "call",
         fn: removeFocus(state),
         input: initialEditorState,
-        resolved: undefined,
       }));
       globalContext?.doHighlight.call();
       // focusNextElement();
@@ -108,7 +95,6 @@ export function ExprBlock({state, setState, onCancel, suggestionPriority}: ExprB
         kind: "call",
         fn: initialEditorState,
         input: removeFocus(state),
-        resolved: undefined,
       }));
       globalContext?.doHighlight.transform();
       return;
@@ -127,9 +113,10 @@ export function ExprBlock({state, setState, onCancel, suggestionPriority}: ExprB
       // we become LetInBlock
       setState(state => ({
         kind: "let",
-        inner: removeFocus(initialEditorState),
         name: "",
+        focus: true,
         value: removeFocus(state),
+        inner: removeFocus(initialEditorState),
       }));  
       globalContext?.doHighlight.let();
       return;
@@ -137,9 +124,10 @@ export function ExprBlock({state, setState, onCancel, suggestionPriority}: ExprB
     if (e.key === 'L' || e.key === '=' && e.shiftKey) {
       setState(state => ({
         kind: "let",
-        inner: removeFocus(state),
         name: "",
+        focus: true,
         value: removeFocus(initialEditorState),
+        inner: removeFocus(state),
       }));
     }
     // a -> lAmbdA
@@ -147,6 +135,7 @@ export function ExprBlock({state, setState, onCancel, suggestionPriority}: ExprB
       setState(state => ({
         kind: "lambda",
         paramName: "",
+        focus: true,
         expr: removeFocus(state),
       }));
       globalContext?.doHighlight.lambda();
@@ -162,6 +151,7 @@ export function ExprBlock({state, setState, onCancel, suggestionPriority}: ExprB
           setState={setState as (callback:(p:InputBlockState)=>ExprBlockState)=>void}
           suggestionPriority={suggestionPriority}
           onCancel={onCancel}
+          addParam={addParam}
         />;
       case "call":
         return <CallBlock
@@ -174,12 +164,14 @@ export function ExprBlock({state, setState, onCancel, suggestionPriority}: ExprB
           state={state}
           setState={setState as (callback:(p:LetInBlockState)=>ExprBlockState)=>void}
           suggestionPriority={suggestionPriority}
+          addParam={addParam}
           />;
       case "lambda":
         return <LambdaBlock
           state={state}
           setState={setState as (callback:(p:LambdaBlockState)=>ExprBlockState)=>void}
           suggestionPriority={suggestionPriority}
+          addParam={addParam}
           />;
     }  
   }

src/InputBlock.css

@@ -9,6 +9,8 @@
   background-color: transparent;
   color: inherit;
   padding: 0;
+  cursor: text;
+  outline: 0;
 }
 .suggest {
   top: 2.4px;

src/InputBlock.tsx

@@ -6,9 +6,12 @@ import { EnvContext } from "./EnvContext";
 import type { Dynamic, ResolvedType } from "./eval";
 import "./InputBlock.css";
 import { Type } from "./Type";
-import type { State2Props } from "./ExprBlock";
+import type { ExprBlockState, State2Props } from "./ExprBlock";
 import { autoInputWidth, focusNextElement, focusPrevElement, setRightMostCaretPosition } from "./util/dom_trickery";
-import { attemptParseLiteral } from "./eval";
+import { attemptParseLiteral, removeFocus } from "./eval";
+import { GlobalContext } from "./GlobalContext";
+import { initialEditorState } from "./configurations";
+import type { CallBlockState } from "./CallBlock";
 
 interface Literal {
   kind: "literal";
@@ -32,8 +35,9 @@ export interface InputBlockState {
 export type SuggestionType = ['literal'|'name', string, Dynamic];
 export type PrioritizedSuggestionType = [number, ...SuggestionType];
 
-interface InputBlockProps extends State2Props<InputBlockState> {
+interface InputBlockProps extends State2Props<InputBlockState,ExprBlockState> {
   onCancel: () => void;
+  addParam: (e: ExprBlockState) => void;
 }
 
 const computeSuggestions = (text, env, suggestionPriority: (s: ResolvedType) => number): PrioritizedSuggestionType[] => {
@@ -55,11 +59,12 @@ const computeSuggestions = (text, env, suggestionPriority: (s: ResolvedType) =>
   ]
   // return []; // <-- uncomment to disable suggestions (useful for debugging)
   return ls
-    .map(suggestion => [suggestionPriority(suggestion[2]), ...suggestion] as PrioritizedSuggestionType)
+    .map((suggestion) => [suggestionPriority(suggestion[2]), ...suggestion] as PrioritizedSuggestionType)
     .sort(([priorityA], [priorityB]) => priorityB - priorityA)
 }
 
-export function InputBlock({ state, setState, suggestionPriority, onCancel }: InputBlockProps) {
+export function InputBlock({ state, setState, suggestionPriority, onCancel, addParam }: InputBlockProps) {
+  const globalContext = useContext(GlobalContext);
   const {text, focus} = state;
   const env = useContext(EnvContext);
   const inputRef = useRef<HTMLInputElement>(null);
@@ -147,7 +152,13 @@ export function InputBlock({ state, setState, suggestionPriority, onCancel }: In
           onCancel();
           e.preventDefault();
         }
-      }
+      },
+      " ": () => {
+        e.preventDefault();
+        if (text.length > 0) {
+          addParam(initialEditorState);
+        }
+      },
     };
     fns[e.key]?.();
   };

src/LambdaBlock.tsx

@@ -9,20 +9,24 @@ import { autoInputWidth } from "./util/dom_trickery";
 
 import "./LambdaBlock.css";
 import { Type } from "./Type";
+import type { CallBlockState } from "./CallBlock";
 
 export interface LambdaBlockState {
   kind: "lambda";
   paramName: string;
+  focus: boolean;
   expr: ExprBlockState;
 }
 
 interface LambdaBlockProps<
   FnState=ExprBlockState,
   InputState=ExprBlockState,
-> extends State2Props<LambdaBlockState,ExprBlockState> {}
+> extends State2Props<LambdaBlockState,ExprBlockState> {
+  addParam: (e: ExprBlockState) => void;
+}
 
 
-export function LambdaBlock({state, setState, suggestionPriority}: LambdaBlockProps) {
+export function LambdaBlock({state, setState, suggestionPriority, addParam}: LambdaBlockProps) {
   const env = useContext(EnvContext);
   const nameRef = useRef<HTMLInputElement>(null);
 
@@ -43,8 +47,10 @@ export function LambdaBlock({state, setState, suggestionPriority}: LambdaBlockPr
   };
 
   useEffect(() => {
-    nameRef.current?.focus();
+    if (state.focus) {
-  }, []);
+      nameRef.current?.focus();
+    }
+  }, [state.focus]);
 
   useEffect(() => autoInputWidth(nameRef, state.paramName, 60), [nameRef, state.paramName]);
 
@@ -75,6 +81,7 @@ export function LambdaBlock({state, setState, suggestionPriority}: LambdaBlockPr
           placeholder="<name>"
           onKeyDown={onChangeName}
           onChange={e => setParamName(e.target.value)}
+          spellCheck={false}
           />
     </span>
     <div className="typeSignature">
@@ -93,6 +100,7 @@ export function LambdaBlock({state, setState, suggestionPriority}: LambdaBlockPr
             // console.log('suggestionPriority of lambdaInner... just passing through');
             return suggestionPriority(s);
           }}
+          addParam={addParam}
           />
       </EnvContext>
     </div>

src/LetInBlock.tsx

@@ -8,15 +8,19 @@ import { autoInputWidth } from "./util/dom_trickery";
 import { GlobalContext } from "./GlobalContext";
 
 import "./LetInBlock.css";
+import type { CallBlockState } from "./CallBlock";
 
 export interface LetInBlockState {
   kind: "let";
   name: string;
+  focus: boolean;
   value: ExprBlockState;
   inner: ExprBlockState;
 }
 
-interface LetInBlockProps extends State2Props<LetInBlockState,ExprBlockState> {}
+interface LetInBlockProps extends State2Props<LetInBlockState,ExprBlockState> {
+  addParam: (e: ExprBlockState) => void;
+}
 
 export function LetInBlock(props: LetInBlockProps) {
   return <span className="letIn">
@@ -29,7 +33,7 @@ export function LetInBlock(props: LetInBlockProps) {
   </span>
 }
 
-function DeclColumns({state: {name, value, inner}, setState, suggestionPriority}) {
+function DeclColumns({state: {name, value, inner, focus}, setState, suggestionPriority, addParam}) {
   const env = useContext(EnvContext);
   const globalContext = useContext(GlobalContext);
 
@@ -47,8 +51,11 @@ function DeclColumns({state: {name, value, inner}, setState, suggestionPriority}
 
   const nameRef = useRef<HTMLInputElement>(null);
   useEffect(() => {
-    nameRef.current?.focus();
+    if (focus) {
-  }, []);
+      nameRef.current?.focus();
+    }
+  }, [focus]);
+
   useEffect(() => autoInputWidth(nameRef, name, 60), [nameRef, name]);
 
   const [valueResolved] = evalEditorBlock(value, env);
@@ -63,6 +70,7 @@ function DeclColumns({state: {name, value, inner}, setState, suggestionPriority}
         value={name}
         placeholder="<name>"
         onChange={onChangeName}
+        spellCheck={false}
         />
       </span>
       <span className="keyword column">&nbsp;=&nbsp;</span>
@@ -72,6 +80,7 @@ function DeclColumns({state: {name, value, inner}, setState, suggestionPriority}
           setState={setValue}
           suggestionPriority={valueSuggestionPriority}
           onCancel={() => setState(state => state.inner)} // keep inner
+          addParam={addParam}
           />
       </span>
     {inner.kind === "let" &&
@@ -81,13 +90,14 @@ function DeclColumns({state: {name, value, inner}, setState, suggestionPriority}
           state={inner}
           setState={setInner}
           suggestionPriority={suggestionPriority}
+          addParam={addParam}
           />
       </EnvContext>
     }
   </>;
 }
 
-function InnerMost({state, setState, suggestionPriority}) {
+function InnerMost({state, setState, suggestionPriority, addParam}) {
   const env = useContext(EnvContext);
   const globalContext = useContext(GlobalContext);
   const setInner = callback => setState(state => ({...state, inner: callback(state.inner)}));
@@ -100,6 +110,7 @@ function InnerMost({state, setState, suggestionPriority}) {
           state={state.inner}
           setState={setInner}
           suggestionPriority={suggestionPriority}
+          addParam={addParam}
           />
       </EnvContext>;
   }
@@ -110,6 +121,7 @@ function InnerMost({state, setState, suggestionPriority}) {
         setState={setInner}
         suggestionPriority={suggestionPriority}
         onCancel={onCancel} // keep value
+        addParam={addParam}
         />
     </EnvContext>
   }

src/eval.ts

@@ -470,4 +470,56 @@ function makeError(env: Environment, e: Error, unification: Unification=new Map(
     nextFreeTypeVar: idx + 1,
     typeVars: new Set([...env.typeVars, UNBOUND_SYMBOLS[idx]]),
   }];
-}
+}
+
+export function removeFocus(state: ExprBlockState): ExprBlockState {
+  if (state.kind === "input") {
+    return { ...state, focus: false };
+  }
+  else if (state.kind === "call") {
+    return {
+      ...state,
+      fn: removeFocus(state.fn),
+      input: removeFocus(state.input),
+    };
+  }
+  else if (state.kind === "lambda") {
+    return {
+      ...state,
+      focus: false,
+      expr: removeFocus(state.expr),
+    };
+  }
+  else { // state.kind === "let"
+    return {
+      ...state,
+      focus: false,
+      value: removeFocus(state.value),
+      inner: removeFocus(state.inner),
+    }
+  }
+}
+
+export function addFocusRightMost(state: ExprBlockState) : ExprBlockState {
+  if (state.kind === "input") {
+    return { ...state, focus: true };
+  }
+  else if (state.kind === "call") {
+    return {
+      ... state,
+      input: addFocusRightMost(state.input),
+    };
+  }
+  else if (state.kind === "lambda") {
+    return {
+      ...state,
+      expr: addFocusRightMost(state.expr),
+    };
+  }
+  else { // state.kind === "let"
+    return {
+      ...state,
+      inner: addFocusRightMost(state.inner),
+    }
+  }
+}