# This program should help you in your second project. It reads the input
# expression, remove blanks, add ( at the beginning and ) at the end and put
# the resulting expression at "Array".
    .data
     v:     .asciiz " ()0123456789*+-"
     exp:   .space 128           # reserve memory locations for data 
     Array: .space 128

    .text
    .globl main
     main:  li     $v0, 8
            li     $a1, 127      # maximum size for input expression
	    la     $a0, exp
            syscall              # read input expression into exp

            la    $t0, exp
	    la    $t1, Array
            la    $t2, v       
            lb    $t2, 1($t2)    # load a ( into $t2
            sb    $t2, 0($t1)    # put ( at the start of the Array
            addi  $t1, $t1, 1
            la    $t2, v
            lb    $t2, 0($t2)    # load a blank into $t2
      ll:   lb    $t3, 0($t0)    # copy exp into Array discarding blanks
            bne   $t2, $t3, jp   # if not blank go to jp
            addi  $t0, $t0, 1
            j     ll
       jp : sb    $t3, 0($t1)
            addi  $t1, $t1, 1
            addi  $t0, $t0, 1
            bne   $t3, $zero, ll # if not <null> (end of string) go to ll

            la    $t2, v
            lb    $t2, 2($t2)    # load a ) into $t2
            sb    $t2, -2($t1)   # insert ) before the <CR> and the <null> in Array
            sb    $zero, -1($t1) # put a null after ) in Array to make it possible
                                 # to print Array as a string. 

            # you should insert your call to Eval here 

	    la     $a0, exp
            li     $v0, 4 
            syscall              # print the string in exp 

	    la     $a0, Array
            li     $v0, 4 
            syscall              # print the string in Array

            li  $2, 10           # prepare to exit with syscall 10
            syscall              # make call

# end of program