Mini Shell

#!/usr/bin/env python
# coding:utf-8
# Authors:  mozman <me@mozman.at>, Florian Festi
# Purpose: svgparser using re module
# Created: 16.10.2010
# Copyright (c) 2010, Manfred Moitzi & 2020, Florian Festi
# License: MIT License

__all__ = ["is_valid_transferlist", "is_valid_pathdata", "is_valid_animation_timing"]

import re

event_names = [
    "focusin", "focusout", "activate", "click", "mousedown", "mouseup", "mouseover",
    "mousemove", "mouseout", "DOMSubtreeModified", "DOMNodeInserted", "DOMNodeRemoved",
    "DOMNodeRemovedFromDocument", "DOMNodeInsertedtoDocument", "DOMAttrModified",
    "DOMCharacterDataModified", "SVGLoad", "SVGUnload", "SVGAbort", "SVGError",
    "SVGResize", "SVGScroll", "SVGZoom", "beginEvent", "endEvent", "repeatEvent",
]

c = r"\s*[, ]\s*"
s = r"\s*[; ]\s*"
integer_constant = r"\d+"
exponent = r"([eE][+-]?\d+)"
nonnegative_number = fr"(\d+\.?\d*|\.\d+){exponent}?"
number = r"[+-]?" + nonnegative_number
flag = r"[01]"

comma_delimited_coordinates = fr"\s*{number}({c}{number})*\s*"
two_comma_delimited_numbers = fr"\s*{number}({c}{number}\s*)" "{1}"
four_comma_delimited_numbers = fr"\s*{number}\s*({c}{number}\s*)" "{3}"
six_comma_delimited_numbers = fr"\s*{number}\s*({c}{number}\s*)" "{5}"
comma_delimited_coordinate_pairs = fr"{two_comma_delimited_numbers}({c}{two_comma_delimited_numbers})*"


def is_valid(regex):
    reg = re.compile(regex)

    def f(term):
        return bool(reg.fullmatch(term))

    return f


def build_transferlist_parser():
    matrix = fr"matrix\s*\(\s*{six_comma_delimited_numbers}\s*\)"
    translate = fr"translate\s*\(\s*{number}({c}{number})?\s*\)"
    scale = fr"scale\s*\(\s*{number}({c}{number})?\s*\)"
    rotate = fr"rotate\s*\(\s*{number}({c}{number}{c}{number})?\s*\)"
    skewX = fr"skewX\s*\(\s*{number}\s*\)"
    skewY = fr"skewY\s*\(\s*{number}\s*\)"

    tl_re = "|".join((fr"(\s*{cmd}\s*)" for cmd in (
        matrix, translate, scale, rotate, skewX, skewY)))
    return fr"({tl_re})({c}({tl_re}))*"


is_valid_transferlist = is_valid(build_transferlist_parser())


def build_pathdata_parser():
    moveto = fr"[mM]\s*{comma_delimited_coordinate_pairs}"
    lineto = fr"[lL]\s*{comma_delimited_coordinate_pairs}"
    horizontal_lineto = fr"[hH]\s*{comma_delimited_coordinates}"
    vertical_lineto = fr"[vV]\s*{comma_delimited_coordinates}"
    curveto = fr"[cC]\s*({six_comma_delimited_numbers})({c}{six_comma_delimited_numbers})*"
    smooth_curveto = fr"[sS]{four_comma_delimited_numbers}({c}{four_comma_delimited_numbers})*"
    quadratic_bezier_curveto = fr"[qQ]{four_comma_delimited_numbers}({c}{four_comma_delimited_numbers})*"
    smooth_quadratic_bezier_curveto = fr"[tT]\s*{comma_delimited_coordinate_pairs}"

    elliptical_arc_argument = fr"{c}".join((
        fr"{nonnegative_number}",
        fr"{nonnegative_number}",
        fr"{number}",
        fr"{flag}",
        fr"{flag}",
        fr"{number}",
        fr"{number}",))
    elliptical_arc_argument = r"\s*" + elliptical_arc_argument + r"\s*"
    elliptical_arc = fr"[aA]({elliptical_arc_argument})({c}{elliptical_arc_argument})*"

    drawto_command = "|".join((fr"(\s*{cmd}\s*)" for cmd in (
        moveto, lineto, horizontal_lineto, vertical_lineto, "[zZ]",
        curveto, smooth_curveto, quadratic_bezier_curveto,
        smooth_quadratic_bezier_curveto, elliptical_arc)))

    return f"{moveto}({drawto_command})*"


is_valid_pathdata = is_valid(build_pathdata_parser())

digit2 = r"\d{2}"
digit4 = r"\d{4}"
seconds = fr"\d+(\.\d+)?"
seconds2 = fr"{digit2}(\.\d+)?"
metric = "(h|min|s|ms)"


def clock_val_re():
    timecount_val = fr"{seconds}\s*({metric})?"
    clock_val = fr"{digit2}:({digit2}:)?{seconds2}"
    return fr"({timecount_val}|{clock_val})"


def wall_clock_val_re():
    hhmmss = fr"{digit2}:{digit2}(:{seconds2})?"
    walltime = fr"{hhmmss}(Z|[+-]?{digit2}:{digit2})?"
    date = fr"{digit4}-{digit2}-{digit2}"
    datetime = fr"{date}(T{walltime})?"
    return "(" + "|".join((walltime, datetime)) + ")"


def build_animation_timing_parser():
    clock_val = clock_val_re()
    wallclock_val = wall_clock_val_re()

    event_ref = "(" + "|".join(event_names) + ")"
    id_value = "#?[-_a-zA-Z0-9]+"

    wallclock_sync_value = fr"wallclock\(\s*{wallclock_val}\s*\)"
    accesskey_value = fr"accessKey\(\s*[a-zA-Z]\s*\)\s*([+-]?{clock_val})?"
    repeat_value = fr"({id_value}\.)?repeat\s*\(\s*\d+\s*\)\s*([+-?]{clock_val})?"
    event_value = fr"({id_value}\.)?{event_ref}([+-]?{clock_val})?"
    offset_value = fr"[-+]?{clock_val}"
    syncbase_value = fr"{id_value}\.(begin|end)({offset_value})?"
    begin_value = "(" + "|".join((f"({reg})" for reg in (
        offset_value, syncbase_value, event_value, repeat_value,
        accesskey_value, wallclock_sync_value, "indefinite"))) + ")"
    return fr"{begin_value}({s}{begin_value})*"


is_valid_animation_timing = is_valid(build_animation_timing_parser())