Pangaea programming language

How to run

Download Binary

See Releases.

Or Build Manually

$ git clone https://github.com/Syuparn/Pangaea.git
$ cd ./Pangaea
$ go generate
$ go build

Or Use Pangaea Playground

Visit https://syuparn.github.io/Pangaea/ !

Also, you can learn Pangaea syntax by an online tutorial Pangaea Travel Guide.

Run

# Run REPL
# (Linux, Mac)
$ ./pangaea
# (Windows)
$ ./pangaea.exe

# Run script file
# (Linux, Mac)
$ ./pangaea ./example/hello.pangaea
# (Windows)
$ ./pangaea.exe ./example/hello.pangaea

# Enjoy!

What can I do?

Examples and unit tests will help you. Also, you can find properties of embedded objects by .keys method.

# properties of Obj starting with "a"
>>> Obj.keys.grep("^a")
["acc", "all?", "ancestors", "any?", "append", "asFor?"]
# with private properties
>>> Obj.keys(private?: true)
["A", "B", "S", "acc", "all?", ...]

# check which property is called
>>> 1.which('+)
Int
>>> 1.which('p)
Obj

Requirements

Host language

• Golang (1.17+)

Dependent Packages

• goyacc
• simplexer
• dtoa
• dedent

Introduction (Let's run your REPL!)

One-way!

This language is tuned for a one-liner method chain! You don't have to go back to beginning of line!

"Hello, world!".puts # Hello, world!
(1:5).A.sum.puts # 10

Looks similar to other language though? But Chains in Pangaea has more power...

Chain context

Dot chain is "one of" the method chains in Pangaea. There are some kinds of chain styles, and each one shows different "context". (The concept is from Perl :) )

There are 3 kinds of chain context(., @, $).

Scalar Chain

The receiver is left-side value, which is ordinary method chain.

10.puts # 10

List Chain

The receiver is each element of left-side value. This can be used as "map" or "filter" in other languages.

[1, 2, 3]@{|i| i * 2}.puts # [2, 4, 6]
["foo", "var", "hoge"]@capital.puts # ["Foo", "Var", "Hoge"]
# select only evens because nils are ignored
(1:10)@{|i| i if i.even?}.puts # [2, 4, 6, 8]

Reduce Chain

The receiver is each element of left-side value. Also, returned value of previous call is passed to 2nd argument. (In short, it's reduce!)

# reduce chain can hold initial value.
[1, 2, 3]$(0){|acc, i| acc+i} # 6
# same as above
[1, 2, 3]$(0)+ # 6

Additional context

Additional context can be prepended by main chain context. There are 3 kinds of additional chain context(&, =, ~). Thus, there are 9 kinds (3 additional * 3 main) of context.

Lonely Chain

This chain ignores call and return nil if its receiver is nil (what a "lonely" object!), which works same as "lonely operator" in Ruby.

# nil.capital.puts # NoPropErr: property `capital` is not defined.
nil&.capital.puts # nil

[1, 2, nil, 4]&@F.puts # [1.000000, 2.000000, 4.000000]

Thoughtful Chain

This chain returns receiver instead if returned value is nil (it "thoughtfully" repairs failed call).

(1:16)~@{|i| ['fizz][i%3] + ['buzz][i%5]}.puts # [1, 2, "fizz", 4, "buzz", ..., "fizzbuzz"]

(3:20)~$([2]){|acc, n| [*acc, n] if acc.all? {|p| n % p}}.puts # [2, 3, 5, ..., 19]

# (Of course you can use built-in prime function)
20.select {.prime?}.puts # [2, 3, 5, ..., 19]

Strict Chain

This chain keeps returned nil value ("strictly" returns the calclation result). This is useful only in list context, which removes returned nil.

(1:10)@{|i| i if i.even?}.puts # [2, 4, 6, 8]
(1:10)=@{|i| i if i.even?}.puts # [nil, 2, nil, 4, nil, 6, nil, 8, nil]

Language Features

• Readable one-liner
• Interpreted
• Dynamically typed
• Prototype-based object oriented
• Everything is object
• Immutable objects
• First-class functions with lexical scopes
• Method chains with context (see above for details)
• Metaprogramming with magic methods (e.g: _missing, asFor?)

See Language Reference for more information.

For Developers

Directories

name	description
.chglog	template of release note
.github	GitHub actions
ast	definition of AST
di	inject native properties into built-in objects
docs	language spec reference
evaluator	evaluator with built-in prop tests
example	pangaea example snippets
native	native properties written in Pangaea
object	definition of Pangaea object system
parser	parser generated from goyacc grammer
props	built-in properties written in Go
runscript	handle interpreter and REPL
tests	native property tests written in Pangaea
third_party	patched dependant Go modules
web	Pangaea Playground

Release

Release note and binary is generated automatically by Goreleaser. You only need to push a new tag to origin. Tag name is set to the binary version (shown by -v).

Contribution

Any contribution is welcome!