|
""" |
|
Rust code printer |
|
|
|
The `RustCodePrinter` converts SymPy expressions into Rust expressions. |
|
|
|
A complete code generator, which uses `rust_code` extensively, can be found |
|
in `sympy.utilities.codegen`. The `codegen` module can be used to generate |
|
complete source code files. |
|
|
|
""" |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
from __future__ import annotations |
|
from typing import Any |
|
|
|
from sympy.core import S, Rational, Float, Lambda |
|
from sympy.core.numbers import equal_valued |
|
from sympy.printing.codeprinter import CodePrinter |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
known_functions = { |
|
|
|
|
|
|
|
|
|
|
|
"floor": "floor", |
|
"ceiling": "ceil", |
|
|
|
|
|
|
|
"Abs": "abs", |
|
"sign": "signum", |
|
|
|
|
|
|
|
"Pow": [(lambda base, exp: equal_valued(exp, -1), "recip", 2), |
|
(lambda base, exp: equal_valued(exp, 0.5), "sqrt", 2), |
|
(lambda base, exp: equal_valued(exp, -0.5), "sqrt().recip", 2), |
|
(lambda base, exp: exp == Rational(1, 3), "cbrt", 2), |
|
(lambda base, exp: equal_valued(base, 2), "exp2", 3), |
|
(lambda base, exp: exp.is_integer, "powi", 1), |
|
(lambda base, exp: not exp.is_integer, "powf", 1)], |
|
"exp": [(lambda exp: True, "exp", 2)], |
|
"log": "ln", |
|
|
|
|
|
|
|
|
|
|
|
"Max": "max", |
|
"Min": "min", |
|
|
|
"sin": "sin", |
|
"cos": "cos", |
|
"tan": "tan", |
|
"asin": "asin", |
|
"acos": "acos", |
|
"atan": "atan", |
|
"atan2": "atan2", |
|
|
|
|
|
|
|
"sinh": "sinh", |
|
"cosh": "cosh", |
|
"tanh": "tanh", |
|
"asinh": "asinh", |
|
"acosh": "acosh", |
|
"atanh": "atanh", |
|
"sqrt": "sqrt", |
|
} |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
reserved_words = ['abstract', |
|
'alignof', |
|
'as', |
|
'become', |
|
'box', |
|
'break', |
|
'const', |
|
'continue', |
|
'crate', |
|
'do', |
|
'else', |
|
'enum', |
|
'extern', |
|
'false', |
|
'final', |
|
'fn', |
|
'for', |
|
'if', |
|
'impl', |
|
'in', |
|
'let', |
|
'loop', |
|
'macro', |
|
'match', |
|
'mod', |
|
'move', |
|
'mut', |
|
'offsetof', |
|
'override', |
|
'priv', |
|
'proc', |
|
'pub', |
|
'pure', |
|
'ref', |
|
'return', |
|
'Self', |
|
'self', |
|
'sizeof', |
|
'static', |
|
'struct', |
|
'super', |
|
'trait', |
|
'true', |
|
'type', |
|
'typeof', |
|
'unsafe', |
|
'unsized', |
|
'use', |
|
'virtual', |
|
'where', |
|
'while', |
|
'yield'] |
|
|
|
|
|
class RustCodePrinter(CodePrinter): |
|
"""A printer to convert SymPy expressions to strings of Rust code""" |
|
printmethod = "_rust_code" |
|
language = "Rust" |
|
|
|
_default_settings: dict[str, Any] = { |
|
'order': None, |
|
'full_prec': 'auto', |
|
'precision': 17, |
|
'user_functions': {}, |
|
'human': True, |
|
'contract': True, |
|
'dereference': set(), |
|
'error_on_reserved': False, |
|
'reserved_word_suffix': '_', |
|
'inline': False, |
|
} |
|
|
|
def __init__(self, settings={}): |
|
CodePrinter.__init__(self, settings) |
|
self.known_functions = dict(known_functions) |
|
userfuncs = settings.get('user_functions', {}) |
|
self.known_functions.update(userfuncs) |
|
self._dereference = set(settings.get('dereference', [])) |
|
self.reserved_words = set(reserved_words) |
|
|
|
def _rate_index_position(self, p): |
|
return p*5 |
|
|
|
def _get_statement(self, codestring): |
|
return "%s;" % codestring |
|
|
|
def _get_comment(self, text): |
|
return "// %s" % text |
|
|
|
def _declare_number_const(self, name, value): |
|
return "const %s: f64 = %s;" % (name, value) |
|
|
|
def _format_code(self, lines): |
|
return self.indent_code(lines) |
|
|
|
def _traverse_matrix_indices(self, mat): |
|
rows, cols = mat.shape |
|
return ((i, j) for i in range(rows) for j in range(cols)) |
|
|
|
def _get_loop_opening_ending(self, indices): |
|
open_lines = [] |
|
close_lines = [] |
|
loopstart = "for %(var)s in %(start)s..%(end)s {" |
|
for i in indices: |
|
|
|
open_lines.append(loopstart % { |
|
'var': self._print(i), |
|
'start': self._print(i.lower), |
|
'end': self._print(i.upper + 1)}) |
|
close_lines.append("}") |
|
return open_lines, close_lines |
|
|
|
def _print_caller_var(self, expr): |
|
if len(expr.args) > 1: |
|
|
|
|
|
|
|
return '(' + self._print(expr) + ')' |
|
elif expr.is_number: |
|
return self._print(expr, _type=True) |
|
else: |
|
return self._print(expr) |
|
|
|
def _print_Function(self, expr): |
|
""" |
|
basic function for printing `Function` |
|
|
|
Function Style : |
|
|
|
1. args[0].func(args[1:]), method with arguments |
|
2. args[0].func(), method without arguments |
|
3. args[1].func(), method without arguments (e.g. (e, x) => x.exp()) |
|
4. func(args), function with arguments |
|
""" |
|
|
|
if expr.func.__name__ in self.known_functions: |
|
cond_func = self.known_functions[expr.func.__name__] |
|
func = None |
|
style = 1 |
|
if isinstance(cond_func, str): |
|
func = cond_func |
|
else: |
|
for cond, func, style in cond_func: |
|
if cond(*expr.args): |
|
break |
|
if func is not None: |
|
if style == 1: |
|
ret = "%(var)s.%(method)s(%(args)s)" % { |
|
'var': self._print_caller_var(expr.args[0]), |
|
'method': func, |
|
'args': self.stringify(expr.args[1:], ", ") if len(expr.args) > 1 else '' |
|
} |
|
elif style == 2: |
|
ret = "%(var)s.%(method)s()" % { |
|
'var': self._print_caller_var(expr.args[0]), |
|
'method': func, |
|
} |
|
elif style == 3: |
|
ret = "%(var)s.%(method)s()" % { |
|
'var': self._print_caller_var(expr.args[1]), |
|
'method': func, |
|
} |
|
else: |
|
ret = "%(func)s(%(args)s)" % { |
|
'func': func, |
|
'args': self.stringify(expr.args, ", "), |
|
} |
|
return ret |
|
elif hasattr(expr, '_imp_') and isinstance(expr._imp_, Lambda): |
|
|
|
return self._print(expr._imp_(*expr.args)) |
|
elif expr.func.__name__ in self._rewriteable_functions: |
|
|
|
target_f, required_fs = self._rewriteable_functions[expr.func.__name__] |
|
if self._can_print(target_f) and all(self._can_print(f) for f in required_fs): |
|
return self._print(expr.rewrite(target_f)) |
|
else: |
|
return self._print_not_supported(expr) |
|
|
|
def _print_Pow(self, expr): |
|
if expr.base.is_integer and not expr.exp.is_integer: |
|
expr = type(expr)(Float(expr.base), expr.exp) |
|
return self._print(expr) |
|
return self._print_Function(expr) |
|
|
|
def _print_Float(self, expr, _type=False): |
|
ret = super()._print_Float(expr) |
|
if _type: |
|
return ret + '_f64' |
|
else: |
|
return ret |
|
|
|
def _print_Integer(self, expr, _type=False): |
|
ret = super()._print_Integer(expr) |
|
if _type: |
|
return ret + '_i32' |
|
else: |
|
return ret |
|
|
|
def _print_Rational(self, expr): |
|
p, q = int(expr.p), int(expr.q) |
|
return '%d_f64/%d.0' % (p, q) |
|
|
|
def _print_Relational(self, expr): |
|
lhs_code = self._print(expr.lhs) |
|
rhs_code = self._print(expr.rhs) |
|
op = expr.rel_op |
|
return "{} {} {}".format(lhs_code, op, rhs_code) |
|
|
|
def _print_Indexed(self, expr): |
|
|
|
dims = expr.shape |
|
elem = S.Zero |
|
offset = S.One |
|
for i in reversed(range(expr.rank)): |
|
elem += expr.indices[i]*offset |
|
offset *= dims[i] |
|
return "%s[%s]" % (self._print(expr.base.label), self._print(elem)) |
|
|
|
def _print_Idx(self, expr): |
|
return expr.label.name |
|
|
|
def _print_Dummy(self, expr): |
|
return expr.name |
|
|
|
def _print_Exp1(self, expr, _type=False): |
|
return "E" |
|
|
|
def _print_Pi(self, expr, _type=False): |
|
return 'PI' |
|
|
|
def _print_Infinity(self, expr, _type=False): |
|
return 'INFINITY' |
|
|
|
def _print_NegativeInfinity(self, expr, _type=False): |
|
return 'NEG_INFINITY' |
|
|
|
def _print_BooleanTrue(self, expr, _type=False): |
|
return "true" |
|
|
|
def _print_BooleanFalse(self, expr, _type=False): |
|
return "false" |
|
|
|
def _print_bool(self, expr, _type=False): |
|
return str(expr).lower() |
|
|
|
def _print_NaN(self, expr, _type=False): |
|
return "NAN" |
|
|
|
def _print_Piecewise(self, expr): |
|
if expr.args[-1].cond != True: |
|
|
|
|
|
raise ValueError("All Piecewise expressions must contain an " |
|
"(expr, True) statement to be used as a default " |
|
"condition. Without one, the generated " |
|
"expression may not evaluate to anything under " |
|
"some condition.") |
|
lines = [] |
|
|
|
for i, (e, c) in enumerate(expr.args): |
|
if i == 0: |
|
lines.append("if (%s) {" % self._print(c)) |
|
elif i == len(expr.args) - 1 and c == True: |
|
lines[-1] += " else {" |
|
else: |
|
lines[-1] += " else if (%s) {" % self._print(c) |
|
code0 = self._print(e) |
|
lines.append(code0) |
|
lines.append("}") |
|
|
|
if self._settings['inline']: |
|
return " ".join(lines) |
|
else: |
|
return "\n".join(lines) |
|
|
|
def _print_ITE(self, expr): |
|
from sympy.functions import Piecewise |
|
return self._print(expr.rewrite(Piecewise, deep=False)) |
|
|
|
def _print_MatrixBase(self, A): |
|
if A.cols == 1: |
|
return "[%s]" % ", ".join(self._print(a) for a in A) |
|
else: |
|
raise ValueError("Full Matrix Support in Rust need Crates (https://crates.io/keywords/matrix).") |
|
|
|
def _print_SparseRepMatrix(self, mat): |
|
|
|
return self._print_not_supported(mat) |
|
|
|
def _print_MatrixElement(self, expr): |
|
return "%s[%s]" % (expr.parent, |
|
expr.j + expr.i*expr.parent.shape[1]) |
|
|
|
def _print_Symbol(self, expr): |
|
|
|
name = super()._print_Symbol(expr) |
|
|
|
if expr in self._dereference: |
|
return '(*%s)' % name |
|
else: |
|
return name |
|
|
|
def _print_Assignment(self, expr): |
|
from sympy.tensor.indexed import IndexedBase |
|
lhs = expr.lhs |
|
rhs = expr.rhs |
|
if self._settings["contract"] and (lhs.has(IndexedBase) or |
|
rhs.has(IndexedBase)): |
|
|
|
|
|
return self._doprint_loops(rhs, lhs) |
|
else: |
|
lhs_code = self._print(lhs) |
|
rhs_code = self._print(rhs) |
|
return self._get_statement("%s = %s" % (lhs_code, rhs_code)) |
|
|
|
def indent_code(self, code): |
|
"""Accepts a string of code or a list of code lines""" |
|
|
|
if isinstance(code, str): |
|
code_lines = self.indent_code(code.splitlines(True)) |
|
return ''.join(code_lines) |
|
|
|
tab = " " |
|
inc_token = ('{', '(', '{\n', '(\n') |
|
dec_token = ('}', ')') |
|
|
|
code = [ line.lstrip(' \t') for line in code ] |
|
|
|
increase = [ int(any(map(line.endswith, inc_token))) for line in code ] |
|
decrease = [ int(any(map(line.startswith, dec_token))) |
|
for line in code ] |
|
|
|
pretty = [] |
|
level = 0 |
|
for n, line in enumerate(code): |
|
if line in ('', '\n'): |
|
pretty.append(line) |
|
continue |
|
level -= decrease[n] |
|
pretty.append("%s%s" % (tab*level, line)) |
|
level += increase[n] |
|
return pretty |
|
|
|
|
|
def rust_code(expr, assign_to=None, **settings): |
|
"""Converts an expr to a string of Rust code |
|
|
|
Parameters |
|
========== |
|
|
|
expr : Expr |
|
A SymPy expression to be converted. |
|
assign_to : optional |
|
When given, the argument is used as the name of the variable to which |
|
the expression is assigned. Can be a string, ``Symbol``, |
|
``MatrixSymbol``, or ``Indexed`` type. This is helpful in case of |
|
line-wrapping, or for expressions that generate multi-line statements. |
|
precision : integer, optional |
|
The precision for numbers such as pi [default=15]. |
|
user_functions : dict, optional |
|
A dictionary where the keys are string representations of either |
|
``FunctionClass`` or ``UndefinedFunction`` instances and the values |
|
are their desired C string representations. Alternatively, the |
|
dictionary value can be a list of tuples i.e. [(argument_test, |
|
cfunction_string)]. See below for examples. |
|
dereference : iterable, optional |
|
An iterable of symbols that should be dereferenced in the printed code |
|
expression. These would be values passed by address to the function. |
|
For example, if ``dereference=[a]``, the resulting code would print |
|
``(*a)`` instead of ``a``. |
|
human : bool, optional |
|
If True, the result is a single string that may contain some constant |
|
declarations for the number symbols. If False, the same information is |
|
returned in a tuple of (symbols_to_declare, not_supported_functions, |
|
code_text). [default=True]. |
|
contract: bool, optional |
|
If True, ``Indexed`` instances are assumed to obey tensor contraction |
|
rules and the corresponding nested loops over indices are generated. |
|
Setting contract=False will not generate loops, instead the user is |
|
responsible to provide values for the indices in the code. |
|
[default=True]. |
|
|
|
Examples |
|
======== |
|
|
|
>>> from sympy import rust_code, symbols, Rational, sin, ceiling, Abs, Function |
|
>>> x, tau = symbols("x, tau") |
|
>>> rust_code((2*tau)**Rational(7, 2)) |
|
'8*1.4142135623731*tau.powf(7_f64/2.0)' |
|
>>> rust_code(sin(x), assign_to="s") |
|
's = x.sin();' |
|
|
|
Simple custom printing can be defined for certain types by passing a |
|
dictionary of {"type" : "function"} to the ``user_functions`` kwarg. |
|
Alternatively, the dictionary value can be a list of tuples i.e. |
|
[(argument_test, cfunction_string)]. |
|
|
|
>>> custom_functions = { |
|
... "ceiling": "CEIL", |
|
... "Abs": [(lambda x: not x.is_integer, "fabs", 4), |
|
... (lambda x: x.is_integer, "ABS", 4)], |
|
... "func": "f" |
|
... } |
|
>>> func = Function('func') |
|
>>> rust_code(func(Abs(x) + ceiling(x)), user_functions=custom_functions) |
|
'(fabs(x) + x.CEIL()).f()' |
|
|
|
``Piecewise`` expressions are converted into conditionals. If an |
|
``assign_to`` variable is provided an if statement is created, otherwise |
|
the ternary operator is used. Note that if the ``Piecewise`` lacks a |
|
default term, represented by ``(expr, True)`` then an error will be thrown. |
|
This is to prevent generating an expression that may not evaluate to |
|
anything. |
|
|
|
>>> from sympy import Piecewise |
|
>>> expr = Piecewise((x + 1, x > 0), (x, True)) |
|
>>> print(rust_code(expr, tau)) |
|
tau = if (x > 0) { |
|
x + 1 |
|
} else { |
|
x |
|
}; |
|
|
|
Support for loops is provided through ``Indexed`` types. With |
|
``contract=True`` these expressions will be turned into loops, whereas |
|
``contract=False`` will just print the assignment expression that should be |
|
looped over: |
|
|
|
>>> from sympy import Eq, IndexedBase, Idx |
|
>>> len_y = 5 |
|
>>> y = IndexedBase('y', shape=(len_y,)) |
|
>>> t = IndexedBase('t', shape=(len_y,)) |
|
>>> Dy = IndexedBase('Dy', shape=(len_y-1,)) |
|
>>> i = Idx('i', len_y-1) |
|
>>> e=Eq(Dy[i], (y[i+1]-y[i])/(t[i+1]-t[i])) |
|
>>> rust_code(e.rhs, assign_to=e.lhs, contract=False) |
|
'Dy[i] = (y[i + 1] - y[i])/(t[i + 1] - t[i]);' |
|
|
|
Matrices are also supported, but a ``MatrixSymbol`` of the same dimensions |
|
must be provided to ``assign_to``. Note that any expression that can be |
|
generated normally can also exist inside a Matrix: |
|
|
|
>>> from sympy import Matrix, MatrixSymbol |
|
>>> mat = Matrix([x**2, Piecewise((x + 1, x > 0), (x, True)), sin(x)]) |
|
>>> A = MatrixSymbol('A', 3, 1) |
|
>>> print(rust_code(mat, A)) |
|
A = [x.powi(2), if (x > 0) { |
|
x + 1 |
|
} else { |
|
x |
|
}, x.sin()]; |
|
""" |
|
|
|
return RustCodePrinter(settings).doprint(expr, assign_to) |
|
|
|
|
|
def print_rust_code(expr, **settings): |
|
"""Prints Rust representation of the given expression.""" |
|
print(rust_code(expr, **settings)) |
|
|