[cvs-nhc98] patch applied (hat): Tidy up SExp code, in particular to put back necessary parentheses in

Sun Apr 17 06:44:31 PDT 2005 malcolm * Tidy up SExp code, in particular to put back necessary parentheses in pretty-printed expressions. Also, do not store the result of an if/case/guard unless needed (by hat-anim), since storing it unnecessarily leads to unbounded resource usage in the other tools. M ./src/hattools/HatStack.hs -1 +1 M ./src/hattools/HatTrail.hs -1 +1 M ./src/hattools/SExp.hs -172 +187 M ./src/hattools/VSExp.hs -6 +7