PlayCode
A Playful Programming Language

PlayCode is procedural because knowing-how is more important than knowing-that, i.e. street smarts. It will most likely be dynamically typed because no one have time for types anyway? There will be numbers, maybe strings, probably arrays, if-statements, while-loops, variables, and comments.

Currently experimenting with the following features:

• Tags @<tag> followed by some statement to define and tag @<tag> followed by nothing to call, so that basically every line can be called from anywhere in the program and return itself once. It's like a macro or lightweight function.

• Swaps swap <a> <b> to swap the values of two variables, which is useful for example when sorting. What else could be swapped? AST branch?

• Inline asserts x -> "2" to assert that x is equal to "2". This is useful for testing and debugging.

Below are examples of valid programs.

print 42

x = 2

if x > 0 {
    print True
} else {
    print False
}

-- swap
x = 2 * 2
y = 2

swap x y

print 1 + (x * y) - (6 / x) -> "6"

-- tags
x = 0

@inc x = x + 1
@inc

print x -> "1"

-- this is a comment

-- this is an assert without output
x -> "2"

-- and this is assert with output
print x -> "2"

Current status

Working on PlayCode to C transpiler (for fun).

Working example: bubble sort

-- bubble sort
x = [5, 3, 8, 4, 2]
n = 5
i = 0
@init_j j = 0
while i < (n - 1) {
    @init_j
    while j < (n - 1) {
        if x[j] > x[j + 1] {
            swap x[j] x[j + 1]
        }
        j = j + 1
    }
    i = i + 1
}
x -> "[2, 3, 4, 5, 8]"

Running python3 pc.py tests/test_bubblesort.pc --tables.

SYMBOL_TABLE: {'x': [2, 3, 4, 5, 8], 'n': 5, 'i': 4, 'j': 4}
TAG_TABLE: {'@init_j': Tree(Token('RULE', 'assign_stmt'), [Tree(Token('RULE', 'identifier'), [Token('CNAME', 'j')]), Tree(Token('RULE', 'expr'), [Tree(Token('RULE', 'term'), [Tree('number', [Token('SIGNED_NUMBER', '0')])])])])}

Inline asserts example

-- bubble sort
x = [5, 3, 8, 4, 2]
n = 5
i = 0
@init_j j = 0
while i < (n - 1) {
    @init_j
    while j < (n - 1) {
        if x[j] > x[j + 1] {
            swap x[j] x[j + 1]
        }
        j = j + 1
    }
    i = i + 1
}

-- bad change
x[2] = 1

x -> "[2, 3, 4, 5, 8]"

Running python3 pc.py --tests.

Running tests
  tests/test_while.pc OK
  tests/test_tags.pc OK
  tests/test_bubblesort.pc Failed
    1 - Assert error: [2, 3, 1, 5, 8] not equal to [2, 3, 4, 5, 8]
  tests/test_swap.pc OK
  tests/test_if.pc OK
Done

TODOs

Using todoparser.sh.

pc.py      167 lines
pcc.py      266 lines
  45:  need visitor for swap?
  220:  python3 pcc.py --tests