Crossandra

Crossandra is a fast and simple tokenization library for Python operating on enums and regular expressions, with a decent amount of configuration.

Installation

Crossandra is available on PyPI and can be installed with pip, or any other Python package manager:

$ pip install crossandra

(Some systems may require you to use pip3, python -m pip, or py -m pip instead)

Documentation

Examples

from enum import Enum
from crossandra import Crossandra

class Brainfuck(Enum):
    ADD = "+"
    SUB = "-"
    LEFT = "<"
    RIGHT = ">"
    READ = ","
    WRITE = "."
    BEGIN_LOOP = "["
    END_LOOP = "]"

bf = Crossandra(Brainfuck, suppress_unknown=True)
print(*bf.tokenize("cat program: ,[.,]"), sep="\n")
# Brainfuck.READ
# Brainfuck.BEGIN_LOOP
# Brainfuck.WRITE
# Brainfuck.READ
# Brainfuck.END_LOOP

from crossandra import Crossandra, Rule, common

def hex2rgb(hex_color: str) -> tuple[int, int, int]:
    r, g, b = (int(hex_color[i:i+2], 16) for i in range(1, 6, 2))
    return r, g, b

t = Crossandra(
    ignore_whitespace=True,
    rules=[
        Rule(r"#[0-9a-fA-F]{6}", hex2rgb),
        common.WORD
    ]
)

text = "My favorite color is #facade"
print(t.tokenize(text))
# ['My', 'favorite', 'color', 'is', (250, 202, 222)]

# Supporting Samarium's numbers and arithmetic operators
from enum import Enum
from crossandra import Crossandra, Rule

def sm_int(string: str) -> int:
    return int(string.replace("/", "1").replace("\\", "0"), 2)

class Op(Enum):
    ADD = "+"
    SUB = "-"
    MUL = "++"
    DIV = "--"
    POW = "+++"
    MOD = "---"

sm = Crossandra(
    Op,
    ignore_whitespace=True,
    rules=[Rule(r"[\\/]+", sm_int)]
)

print(*sm.tokenize(r"//\ ++ /\\/ --- /\/\/ - ///"))
# 6 Op.MUL 9 Op.MOD 21 Op.SUB 7

Contributing

Contributions are welcome!

Please open an issue before submitting a pull request (unless it's a minor change like fixing a typo).

To get started:

1. Clone your fork of the project.
2. Set up the project with just install (uses uv).
3. After you're done, run just check to check your changes.

Note

If you don't want to use just, simply look up the recipes in the project's justfile.

License

Crossandra is licensed under the MIT License.

If you have any questions, or would like to get in touch, join my Discord server!