Sounds like what you're looking for is the original Bash source code, circa 1977, for example [1]:

  LOCAL STRING	copyto(endch)
  	REG CHAR	endch;
  {
  	REG CHAR	c;
  
  	WHILE (c=getch(endch))!=endch ANDF c
  	DO pushstak(c|quote) OD
  	zerostak();
  	IF c!=endch THEN error(badsub) FI
  }

Applicable macros if you want to give your code that classic ALGOL 68 smell in [2].

[1] http://minnie.tuhs.org/cgi-bin/utree.pl?file=V7/usr/src/cmd/...

[2] http://minnie.tuhs.org/cgi-bin/utree.pl?file=V7/usr/src/cmd/...