直接用 Blank Issue 记录一下

1. 形如 2*pi()+3*pi()，需要一个工具函数，把 SymbolicExpr 对象拆分为 有理系数、无理系数（根号)、大数（超过 double 范围的那种）、乱七八糟的东西（如 3^e() 这种不可直视之物，仍然为 SymbolicExpr 对象）
2. 判断两个 SymbolicExpr 是否相等（哈希即可，但需要好用的哈希）

附一个勉强能用的测试脚本

import os
import math
from math import sqrt
import random

# 0.2% error allowed
ALLOW_ERROR = 0.0002

def pi():
    return math.pi

def e():
    return math.e

# Generate random expression (use ** first)
def randexpr(layer):
    if layer <= 0:
        # Return a single term only
        return random.choice([str(random.randint(1,100)),"sqrt({})".format(random.randint(1,100)),"pi()","e()"])
    else:
        rl = random.choice(["{}","({})"]).format(randexpr(layer-1))
        rr = random.choice(["{}","({})"]).format(randexpr(layer-1))
        return rl+random.choice(["+","-","*","/","**"])+rr

def to_lamina(expr):
    return expr.replace("**","^")

while True:
    for i in range(3,7):
        exp = randexpr(i)
        try:
            res = eval(exp)
        except OverflowError as err:
            print("At level",i,": OVF ",str(err))
            continue
        except ZeroDivisionError as err:
            print("At level",i,": ZDE ",str(err))
            continue
        lma = to_lamina(exp)
        f = open("test.lm", "w")
        f.write('print("@",decimal({}));'.format(lma))
        f.close()
        os.system("lamina test.lm 1>out.txt 2>err.log")
        fr = open("out.txt", "r")
        for i in fr.readlines():
            it = i.strip()
            if len(it) < 1:
                continue
            if it[0] == "@":
                its = it[1:].strip()
                itv = float(its)
                err = abs(itv-res)
                err = (err)/abs(res)
                if err > ALLOW_ERROR:
                    print("Error in test!!!")
                    print("Expression:",lma)
                    print("Expected:",res)
                    print("Read:",itv)
                    exit(1)
                else:
                    print("OK,err=",err*100,"%")
                break
        else:
            print("ERROR - RESULT NOT DETECTED")
            exit(2)