input.fj

// ---------- Input Hex


ns hex {
    //  Time Complexity: 2@+7
    // Space Complexity: 2@+18
    //   hex := input(4bits)     // lsb first
    def input_hex hex @ flip0, flip1, flip2, flip3, end < stl.IO {
        // part0
        .zero hex
        wflip stl.IO+w, flip0, stl.IO

        pad 8
      flip0:
        stl.IO+dbit+1;stl.IO        // part1
        hex+dbit+0;flip0    //(part0.5)
      flip1:
        stl.IO+dbit+2;stl.IO        // part2
        hex+dbit+1;flip1    //(part1.5)
      flip3:
        wflip stl.IO+w, flip3, end  // part4
        hex+dbit+3;flip3        //(part3.5)
      flip2:
        stl.IO+dbit+1;stl.IO        // part3
        hex+dbit+2;flip2    //(part2.5)
      end:
    }

    //  Time Complexity: 4@+14
    // Space Complexity: 4@+36
    //   byte[:2] = input(8bits)   // lsb first
    def input byte {
        .input_hex byte
        .input_hex byte+dw
    }

    //  Time Complexity: n(4@+14)
    // Space Complexity: n(4@+36)
    //   bytes[:2n] = input(8n-bits)   // lsb first
    def input n, bytes {
        rep(n, i) .input bytes+2*i*dw
    }

    //  Time Complexity: 7@+11
    // Space Complexity: 8.5@+92
    //   hex = hex_from_ascii(input(1byte))
    // *supports 0-9,a-f,A-F.  if can't cast, jumps to error.
    def input_as_hex hex, error @ try_dec, do_dec, do_hex, hex_switch, finish_hex, upper, end {
        .input_hex hex
        .input_hex upper
        .if_flags upper, (1<<4)|(1<<6), try_dec, do_hex
      try_dec:
        .if_flags upper, (1<<3), error, do_dec

      do_dec:   // if input==0x3i for 0<=i<=9, finish;    else, goto error.
        .if_flags hex, (1<<10)-1, error, end

      do_hex:   // if input==0x4i or input==0x6i:
        wflip hex+w, hex_switch, hex

      finish_hex:
        hex+dbit+3;
        wflip hex+w, hex_switch, end

        pad 16
      hex_switch:   // if 1<=hex<=6, hex+=9;    else, goto error.
        wflip hex+w, hex_switch, error  //  0
        hex+dbit+1;hex_switch+2*dw      //  1
        hex+dbit+0;finish_hex           //  2
        hex+dbit+2;hex_switch+1*dw      //  3
        hex+dbit+0;finish_hex           //  4
        hex+dbit+1;hex_switch+2*dw      //  5
        hex+dbit+0;finish_hex           //  6
        ;hex_switch                     //  7
        ;hex_switch
        ;hex_switch
        ;hex_switch
        ;hex_switch
        ;hex_switch
        ;hex_switch
        ;hex_switch
        ;hex_switch

      upper: .hex
      end:
    }

    //  Time Complexity: n(7@+11)
    // Space Complexity: n(8.5@+92)
    //   hex[:n] = hex_from_ascii(input(n-bytes))
    // *supports 0-9,a-f,A-F.  if can't cast, jumps to error.
    def input_as_hex n, hex, error {
        rep(n, i) .input_as_hex hex + (n-1-i)*dw, error
    }
}