Run-length encoding: Difference between revisions
no edit summary
(added standard ml) |
No edit summary |
||
Line 2,936:
}
Return</lang>
=={{header|XPL0}}==
<lang XPL0>include c:\cxpl\codes; \intrinsic 'code' declarations
string 0; \use zero-terminated strings, instead of MSb terminated
proc Compress(S); \Compress string using run-length encoding, & display it
char S;
int I, C0, C, N;
[I:= 0;
C0:= S(I); I:= I+1;
repeat ChOut(0, C0);
N:= 0;
repeat C:= S(I); I:= I+1;
N:= N+1;
until C#C0;
if N>1 then IntOut(0, N-1);
C0:= C;
until C=0;
]; \Compress
proc Expand(S); \Expand compressed string, and display it
char S;
int I, C0, C, N;
[I:= 0;
C0:= S(I); I:= I+1;
repeat ChOut(0, C0);
C:= S(I); I:= I+1;
if C>=^1 & C<=^9 then
[N:= 0;
while C>=^0 & C<=^9 do
[N:= N*10 + C-^0;
C:= S(I); I:= I+1;
];
while N do [ChOut(0, C0); N:= N-1];
];
C0:= C;
until C=0;
]; \Expand
[Compress("WWWWWWWWWWWWBWWWWWWWWWWWWBBBWWWWWWWWWWWWWWWWWWWWWWWWBWWWWWWWWWWWWWW");
CrLf(0);
Expand("W11BW11B2W23BW13"); CrLf(0);
]</lang>
Output (with slightly better compression than the example):
<pre>
W11BW11B2W23BW13
WWWWWWWWWWWWBWWWWWWWWWWWWBBBWWWWWWWWWWWWWWWWWWWWWWWWBWWWWWWWWWWWWWW
</pre>
| |||