ABS 1.5.0: file writers have landed!

A few hours ago I released a new minor version of the ABS programming language, 1.5.0, which includes a couple of interesting features — let’s get to them!

File writers

Probably one of the most exciting things coming out of this release are file writers: > and >>.

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for x in 1..3 {
    x >> "file.txt"
}

`cat file.txt` // 1\n2\n3

for x in 1..3 {
    x > "file.txt"
}

`cat file.txt` // 3

These operators work as file writers when both the left and right arguments are strings, and proceed to either truncate and write (>) or append (>>).

[].unique()

Arrays now have a .unique() method, used to filter out duplicated elements:

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[1, 2, 2, 3].unique() // [1, 2, 3]

An element is considered duplicate if both its type and string representation match:

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[1, "1", 2, 2].unique() // [1, "1", 2]

For example, different hashes with the same content are considered duplicates:

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a = {"key": "value"}
b = {"key": "value"}
[a, b].unique() // [{"key": "value"}]

Break and continue in for loops

We finally implemented break and continue within for loops: earlier on you could use return to exit a loop but it always felt a tad awkward — with this release this has been fixed.

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x = 0

for v in 1..10 {
    if v < 10 {
        continue
    }

    x += v
}

x // 10

for v in 1..10 {
    if v > 1 {
        break
    }

    x += v
}

x // 11

for..in stackoverflow

We also fixed a bug that resulted in a stack overflow when looping a high number of times in a for..in loop:

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$ for x in 1..10_000_000 { 1 & 2 }
runtime: goroutine stack exceeds 1000000000-byte limit
fatal error: stack overflow

This has been fixed. As a bonus point, for..in loops are also significantly faster with this change (especially noticeable on larger loops, at around 30% faster):

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$ cat for-benchmark.abs
start = `echo $(($(date +%s%N)/1000000))`
for x in 1..1_000_000 { 1 & 2 }
end = `echo $(($(date +%s%N)/1000000))`
echo(end.int() - start.int())

$ abs1.4 for-benchmark.abs
820
$ abs1.5 for-benchmark.abs
546

Now what?

Install ABS with a simple one-liner:

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bash <(curl https://www.abs-lang.org/installer.sh)

…and start scripting like it’s 2019!