ABS preview-3: loads of bugfixes prior to version 1.0

I just released the preview-3 version of ABS, a terse, pragmatic scripting alternative to Bash. This release is geared towards cleaning up bugs before 1.0, so I thought I’d spend some time going through the changes.

Backward-incompatible changes

We got 1 of them!

I first thought of implementing array destructuring with the very same syntax JavaScript uses:

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[x, y] = [1, 2]

but this created a few issues with ABS’ parser. For example, when executing code such as:

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x = 10
[y] = [1]

the parser would see x = 10[y], and throw a truckload of errors. A simple fix was to add a semicolon on the line right before a destructuring statement:

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x = 10;
[y] = [1]

Now, considering I had to fix this as well as the fact that I’m always aiming to keep the language as terse as possible, I took some inspiration from Ruby and refactored destructuring to resemble Ruby’s multiple assignments.

In order to destructure an array, you will now have to:

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x, y = [1, 2]

Easy peasy, with the added bonus of less typing!

Features

Only 1 new feature in this release of ABS: bitwise operators.

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$ abs
Hello alex, welcome to the ABS programming language!
Type 'quit' when you're done, 'help' if you get lost!
⧐  1 & 0
0
⧐  1 ^ 0
1
⧐  1 | 0
1
⧐  1 >> 0
1
⧐  1 << 0
1
⧐  ~1
-2
⧐

Bugfixes

Here’s where the bulk of changes happened:

• null is now an “assignable” value. Earlier on, you couldn’t x = null, which resulted in funny behaviors such as #85
• numbers are not following scientific notation: for very large numbers, the formatter used to convert them to something like 1e+06. This has been now fixed.
• fixed a panic when using .map(...) without return values (#62)
• fixed a panic when calling functions without enough arguments (#61)
• beautified a panic when trying to execute a script that does not exist (#77)
• beautified a panic when trying to execute .sum() on an array with elements other than numbers (#75)
• fixed error handling in .map() and .filter() (#80)
• fixed script halting when there was an error in a while block (#82)
• added \r and \f as a separator for .lines()
• strengthened the command parser (#78)
• fixed shell command escaping (#81)
• destructuring statements do not need a ; on the preceding line anymore (#83)

In other news…

Travis-ci recently launched Windows builds, so I took the opportunity to configure ABS’ builds on Linux, OSX and Windows (#88).

What next?

Ever hoped a bash script could look like:

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# Ask the user what is the best city in the world!
echo("What is the best city in the world?")
selection = stdin()

echo("You picked %s", selection)

tz = $(cat /etc/timezone)
continent, city = tz.split("/")

if selection == city {
    echo("You might be biased...")
} else {
    echo("You know, I heard %s is a nice place as well...", city)
}

# $ abs script.abs
# What is the best city in the world?
# "New York"
# You picked New York
# You know, I heard Rome is a nice place as well...

Hope no more! Simply

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

and start hacking like it’s 2018!