/*-*-Macsyma-*-*/


/*
CASEQ(<var>,'[<keys1>],<stmt1>,
            '[<keys2>],<stmt2>,
            ....,
            '[<keysn>],<stmtn>
            {,'otherwise,<code for no match>})

where the first <stmt> that has <var> as a member of the associated
<keys> is the one chosen to execute.  */


SSTATUS(FEATURE,"gcook caseq")$

CASEQ(VAR,[PAIRS])::=
   IF LENGTH(PAIRS)<=2 THEN
      BLOCK([KEYS:FIRST(PAIRS),STATEMENT:LAST(PAIRS)],
         IF KEYS=OTHERWISE THEN BUILDQ([VAR,STATEMENT],STATEMENT)
         ELSE BUILDQ([VAR,KEYS,STATEMENT],IF MEMBER(VAR,'KEYS) THEN STATEMENT))
   ELSE BUILDQ([VAR,KEYS:FIRST(PAIRS),STATEMENT:FIRST(REST(PAIRS)),
                PAIRS:REST(REST(PAIRS))],
          IF MEMBER(VAR,'KEYS) THEN STATEMENT ELSE CASEQ(VAR,SPLICE(PAIRS)))$

PUSH(C,L)::=(IF SYMBOLP(X) THEN X ELSE ERROR("Arg must be a symbol",X),
             BUILDQ([C,L],L:CONS(C,L)))$