Insertion Sort in Algol68

Welcome to the Insertion Sort in Algol68 page! Here, you'll find the source code for this program as well as a description of how the program works.

Current Solution

MODE PARSEINT_RESULT = STRUCT(BOOL valid, INT value, STRING leftover);
MODE PARSEINTLIST_RESULT = STRUCT(BOOL valid, REF []INT values);

PROC parse int = (REF STRING s) PARSEINT_RESULT:
(
    BOOL valid := FALSE;
    REAL r := 0.0;
    INT n := 0;
    STRING leftover;

    # Associate string with a file #
    FILE f;
    associate(f, s);

    # On end of input, exit if valid number not seen. Otherwise ignore it #
    on logical file end(f, (REF FILE dummy) BOOL:
        (
            IF NOT valid THEN done FI;
            TRUE
        )
    );

    # Exit if value error #
    on value error(f, (REF FILE dummy) BOOL: done);

    # Convert string to real number #
    get(f, r);

    # If real number is in range of an integer, convert to integer. Indicate integer is valid if same as real #
    IF ABS r <= max int
    THEN
        n := ENTIER(r);
        valid := (n = r)
    FI;

    # Get leftover string #
    get(f, leftover);

done:
    close(f);
    PARSEINT_RESULT(valid, n, leftover)
);

PROC count list items = (STRING s) INT:
(
    INT count := 1;
    FOR k TO UPB s
    DO
        IF s[k] = ","
        THEN
            count +:= 1
        FI
    OD;

    count
);

PROC parse int list = (REF STRING s) PARSEINTLIST_RESULT:
(
    BOOL valid := FALSE;
    STRING leftover := s;
    INT num list items = count list items(s);
    HEAP [num list items]INT values;

    # Repeat while valid value #
    FOR k TO num list items
    DO
        # Get next integer value and update leftover string #
        PARSEINT_RESULT result = parse int(leftover);
        valid := valid OF result;
        leftover := leftover OF result;

        # Append the integer value to list #
        values[k] := value OF result;

        # Do nothing if end of string #
        IF leftover = ""
        THEN
            SKIP
        # Skip comma if leftover string starts with comma #
        ELIF leftover[1] = ","
        THEN
            leftover := leftover[2:]
        # Otherwise indicate invalid #
        ELSE
            valid := FALSE
        FI
    UNTIL NOT valid
    OD;

    PARSEINTLIST_RESULT(valid, values)
);

PROC usage = VOID: (
    printf(($gl$, "Usage: please provide a list of at least two integers to sort in the format ""1, 2, 3, 4, 5"""))
);

PROC insertion sort = (REF []INT values) VOID:
(
    COMMENT
    Source: https://en.wikipedia.org/wiki/Insertion_sort#Algorithm
    COMMENT

    INT temp;
    INT j;
    FOR i FROM 2 TO UPB values
    DO
        temp := values[i];
        j := i - 1;
        WHILE j >= 1 ANDF values[j] > temp
        DO
            values[j + 1] := values[j];
            j -:= 1
        OD;
        values[j + 1] := temp
    OD
);

PROC show list values = (REF []INT values) VOID:
(
    INT n = UPB values;
    FOR k TO n
    DO
        IF k > 1
        THEN
            print(", ")
        FI;

        print(whole(values[k], 0))
    OD;

    IF n > 0
    THEN
        print(newline)
    FI
);

# Parse 1st command-line argument #
STRING s := argv(4);
PARSEINTLIST_RESULT list result := parse int list(s);
REF []INT values := values OF list result;
IF NOT valid OF list result OR UPB values < 2
THEN
    usage;
    stop
FI;

# Do insertion sort and show results #
insertion sort(values);
show list values(values)

Insertion Sort in Algol68 was written by:

• rzuckerm

If you see anything you'd like to change or update, please consider contributing.

How to Implement the Solution

No 'How to Implement the Solution' section available. Please consider contributing.

How to Run the Solution

No 'How to Run the Solution' section available. Please consider contributing.