Integer overflow: Difference between revisions

=={{header|jq}}==

The C-based implementation of jq uses IEEE 754 64-bit numbers for numeric computations

without raising errors except for division by 0.

The Go-based implementation of jq, gojq, uses unbounded precision for integer computations

involving infix operators (+, -, %, /), but in the case of division, the result is only guaranteed to be

precise if the divisor is a factor of the dividend. Using gojq, the error raised by an attempt to divide

a number by 0 is catchable.

In the following section, a jq program that implements the task is presented.

The outputs produced by jq and by gojq

are then given.

''The task''

<lang jq>

def compare:

if type == "string" then "\n\(.)\n"

else map(tostring)

| .[1] as $s

| .[0]

| if $s == . then . + ": agrees"

else $s + ": expression evaluates to " + .

end

end;

[ -(-2147483647-1),"2147483648"],

[2000000000 + 2000000000, "4000000000"],

[-2147483647 - 2147483647, "-4294967294"],

[46341 * 46341, "2147488281"],

[(-2147483647-1) / -1, "2147483648"],

"For 64-bit signed integers:",

[-(-9223372036854775807-1), "9223372036854775808"],

[5000000000000000000+5000000000000000000, "10000000000000000000"],

[-9223372036854775807 - 9223372036854775807, "-18446744073709551614"],

[3037000500 * 3037000500, "9223372037000250000"],

[(-9223372036854775807-1) / -1, "9223372036854775808"],

"For 32-bit unsigned integers:",

[-4294967295, "-4294967295"],

[3000000000 + 3000000000, "6000000000"],

[2147483647 - 4294967295, "-2147483648"],

[65537 * 65537, "4295098369"],

"For 64-bit unsigned integers:",

[-18446744073709551615, "-18446744073709551615"],

[10000000000000000000 + 10000000000000000000, "20000000000000000000"],

[9223372036854775807 - 18446744073709551615, "-9223372036854775808"],

[4294967296 * 4294967296, "18446744073709551616"]

| compare</lang>

===jq 1.6===

<pre>2147483648: agrees

4000000000: agrees

-4294967294: agrees

2147488281: agrees

2147483648: agrees

For 64-bit signed integers:

9223372036854775808: expression evaluates to 9223372036854776000

10000000000000000000: expression evaluates to 1e+19

-18446744073709551614: expression evaluates to -18446744073709552000

9223372037000250000: agrees

9223372036854775808: expression evaluates to 9223372036854776000

For 32-bit unsigned integers:

-4294967295: agrees

6000000000: agrees

-2147483648: agrees

4295098369: agrees

For 64-bit unsigned integers:

-18446744073709551615: expression evaluates to -18446744073709552000

20000000000000000000: expression evaluates to 2e+19

-9223372036854775808: expression evaluates to -9223372036854776000

18446744073709551616: expression evaluates to 18446744073709552000

</pre>

===gojq===

<pre>

gojq -nr -f rc-integer-overflow.jq

2147483648: agrees

4000000000: agrees

-4294967294: agrees

2147488281: agrees

2147483648: agrees

For 64-bit signed integers:

9223372036854775808: agrees

10000000000000000000: agrees

-18446744073709551614: agrees

9223372037000250000: agrees

9223372036854775808: agrees

For 32-bit unsigned integers:

-4294967295: agrees

6000000000: agrees

-2147483648: agrees

4295098369: agrees

For 64-bit unsigned integers:

-18446744073709551615: agrees

20000000000000000000: agrees

-9223372036854775808: agrees

18446744073709551616: agrees

</pre>