TeXSCII (/r/dailyprogrammer #217)

TeXSCII.py

# [2015-06-05] Challenge #217 [Practical Exercise] TeXSCII
# http://www.reddit.com/r/dailyprogrammer/comments/38nhgx/20150605_challenge_217_practical_exercise_texscii/

class Symbol:
    def size(self):
        raise Exception("should not be used")
    def draw(self, canvas, x, y):
        raise Exception("should not be used")
    def __repr__(self):
        if self.contents:
            return '<{} {}>'.format(self.__class__.__name__, str(self.contents))
        return '<{}>'.format(self.__class__.__name__)

class MainSymbol(Symbol):
    def size(self):
        return (1, 1)
    def draw(self, canvas, x, y):
        for e in self.contents:
            e.draw(canvas, x, y)
            w, h = e.size()
            x += w

class FracSymbol(Symbol):
    n_arguments = 2
    def subsize(self):
        top_sizes = [e.size() for e in self.contents[0]]
        bot_sizes = [e.size() for e in self.contents[1]]
        topW, topH = sum(xy[0] for xy in top_sizes), max(xy[1] for xy in top_sizes)
        botW, botH = sum(xy[0] for xy in bot_sizes), max(xy[1] for xy in bot_sizes)
        return topW, topH, botW, botH
    def size(self):
        topW, topH, botW, botH = self.subsize()
        return (max(topW, botW), 1 + topH + botH)
    def draw(self, canvas, x, y):
        topW, topH, botW, botH = self.subsize()
        W, H = self.size()
        for dx in range(W):
            canvas[(x+dx, y)] = '—'
        orig_x, orig_y = x, y
        y += botH
        x += (W - botW) // 2
        for e in self.contents[1]:
            e.draw(canvas, x, y)
            x += e.size()[0]
        x, y = orig_x, orig_y - 1
        x += (W - topW) // 2
        for e in self.contents[0]:
            e.draw(canvas, x, y)
            x += e.size()[0]

class RootSymbol(Symbol):
    n_arguments = 2
    def size(self):
        sizes = [e.size() for e in self.contents[1]]
        subW, subH = sum(xy[0] for xy in sizes), max(xy[1] for xy in sizes)
        return (subW + subH, subH + 1)
    def draw(self, canvas, x, y):
        W, H = self.size()
        orig_x, orig_y = x, y
        canvas[(x, y)] = 'v'
        dx, dy = 1, 1
        while dy < H - 1:
            canvas[(x+dx, y-dy)] = '/'
            dx, dy = dx+1, dy+1
        self.contents[0][0].draw(canvas, x+dx-1, y-dy)
        while dx < W:
            canvas[(x+dx, y-dy)] = '_'
            dx += 1
        x += H - 1
        for e in self.contents[1]:
            e.draw(canvas, x, y)
            x += e.size()[0]

class SqrtSymbol(Symbol):
    n_arguments = 1
    def size(self):
        sizes = [e.size() for e in self.contents[0]]
        subW, subH = sum(xy[0] for xy in sizes), max(xy[1] for xy in sizes)
        return (subW + subH, subH + 1)
    def draw(self, canvas, x, y):
        W, H = self.size()
        orig_x, orig_y = x, y
        canvas[(x, y)] = 'v'
        dx, dy = 1, 1
        while dy < H - 1:
            canvas[(x+dx, y-dy)] = '/'
            dx, dy = dx+1, dy+1
        while dx < W:
            canvas[(x+dx, y-dy)] = '_'
            dx += 1
        x, y = orig_x, orig_y
        x += H - 1
        for e in self.contents[0]:
            e.draw(canvas, x, y)
            x += e.size()[0]

class SubSymbol(Symbol):
    n_arguments = 1
    def size(self):
        sizes = [e.size() for e in self.contents[0]]
        return (sum(xy[0] for xy in sizes), 1 + max(xy[1] for xy in sizes))
    def draw(self, canvas, x, y):
        ox, oy = x, y
        y += self.size()[1] - 1
        for e in self.contents[0]:
            e.draw(canvas, x, y)
            x += e.size()[0]

class SupSymbol(Symbol):
    n_arguments = 1
    def size(self):
        sizes = [e.size() for e in self.contents[0]]
        return (sum(xy[0] for xy in sizes), 1 + max(xy[1] for xy in sizes))
    def draw(self, canvas, x, y):
        ox, oy = x, y
        y -= 1
        for e in self.contents[0]:
            e.draw(canvas, x, y)
            x += e.size()[0]

class PiSymbol(Symbol):
    n_arguments = 0
    def size(self):
        return (1, 1)
    def draw(self, canvas, x, y):
        canvas[(x, y)] = 'π'

class CharSymbol(Symbol):
    n_arguments = 0
    def size(self):
        return (1, 1)
    def draw(self, canvas, x, y):
        canvas[(x, y)] = self.contents[0]

symbols = {
    r'\frac': FracSymbol,
    r'\root': RootSymbol,
    r'\sqrt': SqrtSymbol,
    r'\pi': PiSymbol,
    r'_': SubSymbol,
    r'^': SupSymbol
}

def parse(text, pos=0):
    contents = []
    while True:
        for pattern, symClass in symbols.items():
            if text[pos:].startswith(pattern):
                symbol = symClass()
                pos += len(pattern)

                symContents = []
                for i in range(symClass.n_arguments):
                    pos += 1
                    newContents, pos = parse(text, pos)
                    symContents.append(newContents)

                symbol.contents = symContents

                contents.append(symbol)
                break
        else:
            char = CharSymbol()
            char.contents = [text[pos]]
            contents.append(char)
            pos += 1

        if pos == len(text):
            break
        if text[pos] == '}':
            pos += 1
            break

    return contents, pos

output = open("output.txt", "w", encoding='utf-8')

lines = open("input.txt").read().splitlines()
for line in lines:
    contents, _ = parse(line)

    canvas = {}

    root = MainSymbol()
    root.contents = contents
    root.draw(canvas, 0, 0)

    maxX, minX = max(canvas, key=lambda xy: xy[0])[0], min(canvas, key=lambda xy: xy[0])[0]
    maxY, minY = max(canvas, key=lambda xy: xy[1])[1], min(canvas, key=lambda xy: xy[1])[1]

    for y in range(minY, maxY+1):
        for x in range(minX, maxX+1):
            output.write(canvas.get((x, y), ' '))
        output.write('\n')
    output.write('\n\n')