Direct Precedents LAMBDA Function

DIRECTPRECEDENTS.lambda

/*
Name: Direct Precedents (DIRECTPRECEDENTS)
Description: Lists all direct precedents for specified cell.
Author: Excel Robot (@ExcelRobot)
Category: Formula
*/
DIRECTPRECEDENTS = LAMBDA(cell,LET(
   tokens, TOKENIZEFORMULA(OFFSET(cell,0,0,1,1)),
   isterm, INDEX(tokens,,1)="Term",
   activesheetname, MID(CELL("filename",INDIRECT("$A$1")),FIND("]",CELL("filename",INDIRECT("$A$1")))+1,999),
   cellsheetname, MID(CELL("filename",cell),FIND("]",CELL("filename",cell))+1,999),
   isaddress, IFERROR(CELL("address",INDIRECT(INDEX(tokens,,2))),IFERROR(CELL("address",INDIRECT("'"&cellsheetname&"'!"&INDEX(tokens,,2))),""))<>"",
   relativetocell, INDEX(FILTER(tokens,isterm*isaddress),,2),
   relativetoactivesheet, IF(ISERROR(FIND("!",relativetocell)),IF(ISERROR(CELL("address",INDIRECT(cellsheetname&"!"&relativetocell))),"'"&cellsheetname&"'!",cellsheetname&"!")&relativetocell,relativetocell),
   removeactivesheet, IF((LEFT(relativetoactivesheet,LEN(activesheetname&"!"))=activesheetname&"!")+(LEFT(relativetoactivesheet,LEN("'"&activesheetname&"!"))="'"&activesheetname&"'!"),MID(relativetoactivesheet,FIND("!",relativetoactivesheet)+1,999),relativetoactivesheet),
   precedents, unique(removeactivesheet),
   precedents
));

/*
Name: Tokenize Formula (TOKENIZEFORMULA)
Description: Takes the formula from a given cell and breaks down the formula text into
    discrete tokenized parts.  Supports the following token types: Argument Seperator, 
    Array Row Seperator, Close Array, Close Paren, Comparison, Formula Begin, Function, 
    Open Array, Open Paren, Operator, Term, White Space.
Author: Excel Robot (@ExcelRobot)
Category: Formula
*/
TOKENIZEFORMULA = LAMBDA(Cell,LET(
    Formula, FORMULATEXT(Cell),
    Chars, MID(Formula,SEQUENCE(LEN(Formula)),1),
    PriorChars, IFERROR(MID(Formula,SEQUENCE(LEN(Formula),,0),1),""),
    PriorPriorChars, IFERROR(MID(Formula,SEQUENCE(LEN(Formula),,-1),1),""),
    NextChars, IFERROR(MID(Formula,SEQUENCE(LEN(Formula),,2),1),""),
    IsQuote, Chars="""",
    QuoteCount, SCAN(0,IsQuote,LAMBDA(tot,x,tot+x)),
    NotInQuote, NOT(IF((QuoteCount=1)*IsQuote,FALSE,IF(ISODD(+QuoteCount),TRUE,IF(IsQuote*(NextChars="""")*(QuoteCount>0),TRUE,FALSE)))),
    IsOpenParen, (Chars="(")*NotInQuote,
    IsCloseParen, (Chars=")")*NotInQuote,
    IsNotExponent, NotInQuote*(((Chars="+")+(Chars="-"))>0)*(PriorChars="E")*NOT(ISERROR(VALUE(PriorPriorChars)))*NOT(ISERROR(VALUE(NextChars)))=0,
    IsComparison, ((Chars="<")+(Chars=">")+(Chars="="))*NotInQuote*(PriorChars<>"")>0,
    OperatorList, {"+";"-";"*";"/";"^";"&"},
    IsOperator, BYROW(Chars,LAMBDA(x,OR(x=OperatorList)))*NotInQuote*IsNotExponent<>0,
    IsOpenArray, (Chars="{")*NotInQuote,
    IsCloseArray, (Chars="}")*NotInQuote,
    ArrayCount, SCAN(0,IsOpenArray-IsCloseArray,LAMBDA(tot,x,tot+x)),
    InArray, ArrayCount>0,
    IsArgSeperator, (Chars=",")*NotInQuote*(1-InArray)>0,
    IsArrayColSeperator, (Chars=",")*InArray>0,
    IsArrayRowSeperator, (Chars=";")*InArray>0,
    IsWhiteSpace, ((Chars=" ")+(Chars=CHAR(10))+(Chars=CHAR(13)))*NotInQuote>0,
    TokenTypePass1, IFS((Chars="=")*(PriorChars=""),"Formula Begin",IsOpenParen,"Open Paren",IsCloseParen,"Close Paren",IsComparison,"Comparison",IsOperator,"Operator",IsOpenArray,"Open Array",IsCloseArray,"Close Array",IsArgSeperator,"Argument Seperator",IsArrayColSeperator,"Array Column Seperator",IsArrayRowSeperator,"Array Row Seperator",IsWhiteSpace,"White Space",TRUE,"Term"),
    TokenTypePass2, IF(SCAN(0,TokenTypePass1,LAMBDA(tot,x,SWITCH(x,"Term",0,"Open Paren",1,"Argument Seperator",1,"Array Row Seperator",1,"Array Column Seperator",1,"Operator",tot+1,tot)))>1,"Term",TokenTypePass1),
    TokenIndex, SCAN(0,IF((INDEX(TokenTypePass2,SEQUENCE(ROWS(TokenTypePass2),,0))=TokenTypePass2)*(PriorChars<>"")*(((TokenTypePass2="Term")+(TokenTypePass2="Comparison")+(TokenTypePass2="White Space"))>0),0,1),LAMBDA(tot,x,tot+x)),
    TokenTypes, LET(TokenTypeLookup,XLOOKUP(SEQUENCE(MAX(TokenIndex)),TokenIndex,TokenTypePass2),NextTokenType,XLOOKUP(SEQUENCE(MAX(TokenIndex))+1,TokenIndex,TokenTypePass2,""),IF((TokenTypeLookup="Term")*(NextTokenType="Open Paren"),"Function",TokenTypeLookup)),
    Tokens, BYROW(SEQUENCE(MAX(TokenIndex)),LAMBDA(x,TEXTJOIN("",,FILTER(Chars,TokenIndex=x)))),
    Tokenized, MAKEARRAY(ROWS(TokenTypes),2,LAMBDA(x,y,IF(y=1,INDEX(TokenTypes,x),INDEX(Tokens,x)))),
    Tokenized
));