pl@nereida:~/Lperltesting$ ./calc510withactions3.pl
2-8*4/2/4-1
2               rt -> empty
2               term-> digits(2) rt
2-8*4/2/4       rt -> empty
2-8*4/2/4       rt -> [*/] digits(4) rt
2-8*4/2/4       rt -> [*/] digits(2) rt
2-8*4/2/4       rt -> [*/] digits(4) rt
2-8*4/2/4       term-> digits(8) rt
2-8*4/2/4-1     rt -> empty
2-8*4/2/4-1     term-> digits(1) rt
2-8*4/2/4-1     re -> empty
2-8*4/2/4-1     re -> [+-] term re
2-8*4/2/4-1     re -> [+-] term re
2-8*4/2/4-1     exp -> term re
matches: 2-8*4/2/4-1
Stack=(2 8 4 * 2 / 4 / - 1 -)