# Ported from latex2sympy by @augustt198 # https://github.com/augustt198/latex2sympy # See license in LICENSE.txt from importlib.metadata import version import sympy from sympy.external import import_module from sympy.printing.str import StrPrinter from sympy.physics.quantum.state import Bra, Ket from .errors import LaTeXParsingError LaTeXParser = LaTeXLexer = MathErrorListener = None try: LaTeXParser = import_module('sympy.parsing.latex._antlr.latexparser', import_kwargs={'fromlist': ['LaTeXParser']}).LaTeXParser LaTeXLexer = import_module('sympy.parsing.latex._antlr.latexlexer', import_kwargs={'fromlist': ['LaTeXLexer']}).LaTeXLexer except Exception: pass ErrorListener = import_module('antlr4.error.ErrorListener', warn_not_installed=True, import_kwargs={'fromlist': ['ErrorListener']} ) if ErrorListener: class MathErrorListener(ErrorListener.ErrorListener): # type: ignore def __init__(self, src): super(ErrorListener.ErrorListener, self).__init__() self.src = src def syntaxError(self, recog, symbol, line, col, msg, e): fmt = "%s\n%s\n%s" marker = "~" * col + "^" if msg.startswith("missing"): err = fmt % (msg, self.src, marker) elif msg.startswith("no viable"): err = fmt % ("I expected something else here", self.src, marker) elif msg.startswith("mismatched"): names = LaTeXParser.literalNames expected = [ names[i] for i in e.getExpectedTokens() if i < len(names) ] if len(expected) < 10: expected = " ".join(expected) err = (fmt % ("I expected one of these: " + expected, self.src, marker)) else: err = (fmt % ("I expected something else here", self.src, marker)) else: err = fmt % ("I don't understand this", self.src, marker) raise LaTeXParsingError(err) def parse_latex(sympy): antlr4 = import_module('antlr4') if None in [antlr4, MathErrorListener] or \ not version('antlr4-python3-runtime').startswith('4.11'): raise ImportError("LaTeX parsing requires the antlr4 Python package," " provided by pip (antlr4-python3-runtime) or" " conda (antlr-python-runtime), version 4.11") matherror = MathErrorListener(sympy) stream = antlr4.InputStream(sympy) lex = LaTeXLexer(stream) lex.removeErrorListeners() lex.addErrorListener(matherror) tokens = antlr4.CommonTokenStream(lex) parser = LaTeXParser(tokens) # remove default console error listener parser.removeErrorListeners() parser.addErrorListener(matherror) relation = parser.math().relation() expr = convert_relation(relation) return expr def convert_relation(rel): if rel.expr(): return convert_expr(rel.expr()) lh = convert_relation(rel.relation(0)) rh = convert_relation(rel.relation(1)) if rel.LT(): return sympy.StrictLessThan(lh, rh) elif rel.LTE(): return sympy.LessThan(lh, rh) elif rel.GT(): return sympy.StrictGreaterThan(lh, rh) elif rel.GTE(): return sympy.GreaterThan(lh, rh) elif rel.EQUAL(): return sympy.Eq(lh, rh) elif rel.NEQ(): return sympy.Ne(lh, rh) def convert_expr(expr): return convert_add(expr.additive()) def convert_add(add): if add.ADD(): lh = convert_add(add.additive(0)) rh = convert_add(add.additive(1)) return sympy.Add(lh, rh, evaluate=False) elif add.SUB(): lh = convert_add(add.additive(0)) rh = convert_add(add.additive(1)) if hasattr(rh, "is_Atom") and rh.is_Atom: return sympy.Add(lh, -1 * rh, evaluate=False) return sympy.Add(lh, sympy.Mul(-1, rh, evaluate=False), evaluate=False) else: return convert_mp(add.mp()) def convert_mp(mp): if hasattr(mp, 'mp'): mp_left = mp.mp(0) mp_right = mp.mp(1) else: mp_left = mp.mp_nofunc(0) mp_right = mp.mp_nofunc(1) if mp.MUL() or mp.CMD_TIMES() or mp.CMD_CDOT(): lh = convert_mp(mp_left) rh = convert_mp(mp_right) return sympy.Mul(lh, rh, evaluate=False) elif mp.DIV() or mp.CMD_DIV() or mp.COLON(): lh = convert_mp(mp_left) rh = convert_mp(mp_right) return sympy.Mul(lh, sympy.Pow(rh, -1, evaluate=False), evaluate=False) else: if hasattr(mp, 'unary'): return convert_unary(mp.unary()) else: return convert_unary(mp.unary_nofunc()) def convert_unary(unary): if hasattr(unary, 'unary'): nested_unary = unary.unary() else: nested_unary = unary.unary_nofunc() if hasattr(unary, 'postfix_nofunc'): first = unary.postfix() tail = unary.postfix_nofunc() postfix = [first] + tail else: postfix = unary.postfix() if unary.ADD(): return convert_unary(nested_unary) elif unary.SUB(): numabs = convert_unary(nested_unary) # Use Integer(-n) instead of Mul(-1, n) return -numabs elif postfix: return convert_postfix_list(postfix) def convert_postfix_list(arr, i=0): if i >= len(arr): raise LaTeXParsingError("Index out of bounds") res = convert_postfix(arr[i]) if isinstance(res, sympy.Expr): if i == len(arr) - 1: return res # nothing to multiply by else: if i > 0: left = convert_postfix(arr[i - 1]) right = convert_postfix(arr[i + 1]) if isinstance(left, sympy.Expr) and isinstance( right, sympy.Expr): left_syms = convert_postfix(arr[i - 1]).atoms(sympy.Symbol) right_syms = convert_postfix(arr[i + 1]).atoms( sympy.Symbol) # if the left and right sides contain no variables and the # symbol in between is 'x', treat as multiplication. if not (left_syms or right_syms) and str(res) == 'x': return convert_postfix_list(arr, i + 1) # multiply by next return sympy.Mul( res, convert_postfix_list(arr, i + 1), evaluate=False) else: # must be derivative wrt = res[0] if i == len(arr) - 1: raise LaTeXParsingError("Expected expression for derivative") else: expr = convert_postfix_list(arr, i + 1) return sympy.Derivative(expr, wrt) def do_subs(expr, at): if at.expr(): at_expr = convert_expr(at.expr()) syms = at_expr.atoms(sympy.Symbol) if len(syms) == 0: return expr elif len(syms) > 0: sym = next(iter(syms)) return expr.subs(sym, at_expr) elif at.equality(): lh = convert_expr(at.equality().expr(0)) rh = convert_expr(at.equality().expr(1)) return expr.subs(lh, rh) def convert_postfix(postfix): if hasattr(postfix, 'exp'): exp_nested = postfix.exp() else: exp_nested = postfix.exp_nofunc() exp = convert_exp(exp_nested) for op in postfix.postfix_op(): if op.BANG(): if isinstance(exp, list): raise LaTeXParsingError("Cannot apply postfix to derivative") exp = sympy.factorial(exp, evaluate=False) elif op.eval_at(): ev = op.eval_at() at_b = None at_a = None if ev.eval_at_sup(): at_b = do_subs(exp, ev.eval_at_sup()) if ev.eval_at_sub(): at_a = do_subs(exp, ev.eval_at_sub()) if at_b is not None and at_a is not None: exp = sympy.Add(at_b, -1 * at_a, evaluate=False) elif at_b is not None: exp = at_b elif at_a is not None: exp = at_a return exp def convert_exp(exp): if hasattr(exp, 'exp'): exp_nested = exp.exp() else: exp_nested = exp.exp_nofunc() if exp_nested: base = convert_exp(exp_nested) if isinstance(base, list): raise LaTeXParsingError("Cannot raise derivative to power") if exp.atom(): exponent = convert_atom(exp.atom()) elif exp.expr(): exponent = convert_expr(exp.expr()) return sympy.Pow(base, exponent, evaluate=False) else: if hasattr(exp, 'comp'): return convert_comp(exp.comp()) else: return convert_comp(exp.comp_nofunc()) def convert_comp(comp): if comp.group(): return convert_expr(comp.group().expr()) elif comp.abs_group(): return sympy.Abs(convert_expr(comp.abs_group().expr()), evaluate=False) elif comp.atom(): return convert_atom(comp.atom()) elif comp.floor(): return convert_floor(comp.floor()) elif comp.ceil(): return convert_ceil(comp.ceil()) elif comp.func(): return convert_func(comp.func()) def convert_atom(atom): if atom.LETTER(): sname = atom.LETTER().getText() if atom.subexpr(): if atom.subexpr().expr(): # subscript is expr subscript = convert_expr(atom.subexpr().expr()) else: # subscript is atom subscript = convert_atom(atom.subexpr().atom()) sname += '_{' + StrPrinter().doprint(subscript) + '}' if atom.SINGLE_QUOTES(): sname += atom.SINGLE_QUOTES().getText() # put after subscript for easy identify return sympy.Symbol(sname) elif atom.SYMBOL(): s = atom.SYMBOL().getText()[1:] if s == "infty": return sympy.oo else: if atom.subexpr(): subscript = None if atom.subexpr().expr(): # subscript is expr subscript = convert_expr(atom.subexpr().expr()) else: # subscript is atom subscript = convert_atom(atom.subexpr().atom()) subscriptName = StrPrinter().doprint(subscript) s += '_{' + subscriptName + '}' return sympy.Symbol(s) elif atom.number(): s = atom.number().getText().replace(",", "") return sympy.Number(s) elif atom.DIFFERENTIAL(): var = get_differential_var(atom.DIFFERENTIAL()) return sympy.Symbol('d' + var.name) elif atom.mathit(): text = rule2text(atom.mathit().mathit_text()) return sympy.Symbol(text) elif atom.frac(): return convert_frac(atom.frac()) elif atom.binom(): return convert_binom(atom.binom()) elif atom.bra(): val = convert_expr(atom.bra().expr()) return Bra(val) elif atom.ket(): val = convert_expr(atom.ket().expr()) return Ket(val) def rule2text(ctx): stream = ctx.start.getInputStream() # starting index of starting token startIdx = ctx.start.start # stopping index of stopping token stopIdx = ctx.stop.stop return stream.getText(startIdx, stopIdx) def convert_frac(frac): diff_op = False partial_op = False if frac.lower and frac.upper: lower_itv = frac.lower.getSourceInterval() lower_itv_len = lower_itv[1] - lower_itv[0] + 1 if (frac.lower.start == frac.lower.stop and frac.lower.start.type == LaTeXLexer.DIFFERENTIAL): wrt = get_differential_var_str(frac.lower.start.text) diff_op = True elif (lower_itv_len == 2 and frac.lower.start.type == LaTeXLexer.SYMBOL and frac.lower.start.text == '\\partial' and (frac.lower.stop.type == LaTeXLexer.LETTER or frac.lower.stop.type == LaTeXLexer.SYMBOL)): partial_op = True wrt = frac.lower.stop.text if frac.lower.stop.type == LaTeXLexer.SYMBOL: wrt = wrt[1:] if diff_op or partial_op: wrt = sympy.Symbol(wrt) if (diff_op and frac.upper.start == frac.upper.stop and frac.upper.start.type == LaTeXLexer.LETTER and frac.upper.start.text == 'd'): return [wrt] elif (partial_op and frac.upper.start == frac.upper.stop and frac.upper.start.type == LaTeXLexer.SYMBOL and frac.upper.start.text == '\\partial'): return [wrt] upper_text = rule2text(frac.upper) expr_top = None if diff_op and upper_text.startswith('d'): expr_top = parse_latex(upper_text[1:]) elif partial_op and frac.upper.start.text == '\\partial': expr_top = parse_latex(upper_text[len('\\partial'):]) if expr_top: return sympy.Derivative(expr_top, wrt) if frac.upper: expr_top = convert_expr(frac.upper) else: expr_top = sympy.Number(frac.upperd.text) if frac.lower: expr_bot = convert_expr(frac.lower) else: expr_bot = sympy.Number(frac.lowerd.text) inverse_denom = sympy.Pow(expr_bot, -1, evaluate=False) if expr_top == 1: return inverse_denom else: return sympy.Mul(expr_top, inverse_denom, evaluate=False) def convert_binom(binom): expr_n = convert_expr(binom.n) expr_k = convert_expr(binom.k) return sympy.binomial(expr_n, expr_k, evaluate=False) def convert_floor(floor): val = convert_expr(floor.val) return sympy.floor(val, evaluate=False) def convert_ceil(ceil): val = convert_expr(ceil.val) return sympy.ceiling(val, evaluate=False) def convert_func(func): if func.func_normal(): if func.L_PAREN(): # function called with parenthesis arg = convert_func_arg(func.func_arg()) else: arg = convert_func_arg(func.func_arg_noparens()) name = func.func_normal().start.text[1:] # change arc -> a if name in [ "arcsin", "arccos", "arctan", "arccsc", "arcsec", "arccot" ]: name = "a" + name[3:] expr = getattr(sympy.functions, name)(arg, evaluate=False) if name in ["arsinh", "arcosh", "artanh"]: name = "a" + name[2:] expr = getattr(sympy.functions, name)(arg, evaluate=False) if name == "exp": expr = sympy.exp(arg, evaluate=False) if name in ("log", "lg", "ln"): if func.subexpr(): if func.subexpr().expr(): base = convert_expr(func.subexpr().expr()) else: base = convert_atom(func.subexpr().atom()) elif name == "lg": # ISO 80000-2:2019 base = 10 elif name in ("ln", "log"): # SymPy's latex printer prints ln as log by default base = sympy.E expr = sympy.log(arg, base, evaluate=False) func_pow = None should_pow = True if func.supexpr(): if func.supexpr().expr(): func_pow = convert_expr(func.supexpr().expr()) else: func_pow = convert_atom(func.supexpr().atom()) if name in [ "sin", "cos", "tan", "csc", "sec", "cot", "sinh", "cosh", "tanh" ]: if func_pow == -1: name = "a" + name should_pow = False expr = getattr(sympy.functions, name)(arg, evaluate=False) if func_pow and should_pow: expr = sympy.Pow(expr, func_pow, evaluate=False) return expr elif func.LETTER() or func.SYMBOL(): if func.LETTER(): fname = func.LETTER().getText() elif func.SYMBOL(): fname = func.SYMBOL().getText()[1:] fname = str(fname) # can't be unicode if func.subexpr(): if func.subexpr().expr(): # subscript is expr subscript = convert_expr(func.subexpr().expr()) else: # subscript is atom subscript = convert_atom(func.subexpr().atom()) subscriptName = StrPrinter().doprint(subscript) fname += '_{' + subscriptName + '}' if func.SINGLE_QUOTES(): fname += func.SINGLE_QUOTES().getText() input_args = func.args() output_args = [] while input_args.args(): # handle multiple arguments to function output_args.append(convert_expr(input_args.expr())) input_args = input_args.args() output_args.append(convert_expr(input_args.expr())) return sympy.Function(fname)(*output_args) elif func.FUNC_INT(): return handle_integral(func) elif func.FUNC_SQRT(): expr = convert_expr(func.base) if func.root: r = convert_expr(func.root) return sympy.root(expr, r, evaluate=False) else: return sympy.sqrt(expr, evaluate=False) elif func.FUNC_OVERLINE(): expr = convert_expr(func.base) return sympy.conjugate(expr, evaluate=False) elif func.FUNC_SUM(): return handle_sum_or_prod(func, "summation") elif func.FUNC_PROD(): return handle_sum_or_prod(func, "product") elif func.FUNC_LIM(): return handle_limit(func) def convert_func_arg(arg): if hasattr(arg, 'expr'): return convert_expr(arg.expr()) else: return convert_mp(arg.mp_nofunc()) def handle_integral(func): if func.additive(): integrand = convert_add(func.additive()) elif func.frac(): integrand = convert_frac(func.frac()) else: integrand = 1 int_var = None if func.DIFFERENTIAL(): int_var = get_differential_var(func.DIFFERENTIAL()) else: for sym in integrand.atoms(sympy.Symbol): s = str(sym) if len(s) > 1 and s[0] == 'd': if s[1] == '\\': int_var = sympy.Symbol(s[2:]) else: int_var = sympy.Symbol(s[1:]) int_sym = sym if int_var: integrand = integrand.subs(int_sym, 1) else: # Assume dx by default int_var = sympy.Symbol('x') if func.subexpr(): if func.subexpr().atom(): lower = convert_atom(func.subexpr().atom()) else: lower = convert_expr(func.subexpr().expr()) if func.supexpr().atom(): upper = convert_atom(func.supexpr().atom()) else: upper = convert_expr(func.supexpr().expr()) return sympy.Integral(integrand, (int_var, lower, upper)) else: return sympy.Integral(integrand, int_var) def handle_sum_or_prod(func, name): val = convert_mp(func.mp()) iter_var = convert_expr(func.subeq().equality().expr(0)) start = convert_expr(func.subeq().equality().expr(1)) if func.supexpr().expr(): # ^{expr} end = convert_expr(func.supexpr().expr()) else: # ^atom end = convert_atom(func.supexpr().atom()) if name == "summation": return sympy.Sum(val, (iter_var, start, end)) elif name == "product": return sympy.Product(val, (iter_var, start, end)) def handle_limit(func): sub = func.limit_sub() if sub.LETTER(): var = sympy.Symbol(sub.LETTER().getText()) elif sub.SYMBOL(): var = sympy.Symbol(sub.SYMBOL().getText()[1:]) else: var = sympy.Symbol('x') if sub.SUB(): direction = "-" elif sub.ADD(): direction = "+" else: direction = "+-" approaching = convert_expr(sub.expr()) content = convert_mp(func.mp()) return sympy.Limit(content, var, approaching, direction) def get_differential_var(d): text = get_differential_var_str(d.getText()) return sympy.Symbol(text) def get_differential_var_str(text): for i in range(1, len(text)): c = text[i] if not (c == " " or c == "\r" or c == "\n" or c == "\t"): idx = i break text = text[idx:] if text[0] == "\\": text = text[1:] return text