FFI for WMC with complex numbers (#191)

* FFI for complex-valued WMC

* Remove dupe bdd_num_recursive_calls

src/ffi.rs

@@ -2,7 +2,7 @@ use std::os::raw::c_char;
 use std::{collections::HashMap, ffi::CStr};
 
 use crate::repr::DDNNFPtr;
-use crate::util::semirings::{RealSemiring, Semiring};
+use crate::util::semirings::{Complex, RealSemiring, Semiring};
 use crate::{
     builder::{bdd::RobddBuilder, cache::AllIteTable, BottomUpBuilder},
     constants::primes,
@@ -270,12 +270,27 @@ pub unsafe extern "C" fn bdd_wmc(
     DDNNFPtr::unsmoothed_wmc(&(*bdd), &(*wmc)).0
 }
 
+#[no_mangle]
+#[allow(clippy::missing_safety_doc)]
+pub unsafe extern "C" fn bdd_wmc_complex(
+    bdd: *mut BddPtr<'static>,
+    wmc: *mut WmcParams<Complex>,
+) -> Complex {
+    DDNNFPtr::unsmoothed_wmc(&(*bdd), &(*wmc))
+}
+
 #[no_mangle]
 #[allow(clippy::missing_safety_doc)]
 pub unsafe extern "C" fn new_wmc_params_f64() -> *mut WmcParams<RealSemiring> {
     Box::into_raw(Box::new(WmcParams::new(HashMap::from([]))))
 }
 
+#[no_mangle]
+#[allow(clippy::missing_safety_doc)]
+pub unsafe extern "C" fn new_wmc_params_complex() -> *mut WmcParams<Complex> {
+    Box::into_raw(Box::new(WmcParams::new(HashMap::from([]))))
+}
+
 #[no_mangle]
 #[allow(clippy::missing_safety_doc)]
 pub unsafe extern "C" fn wmc_param_f64_set_weight(
@@ -287,6 +302,17 @@ pub unsafe extern "C" fn wmc_param_f64_set_weight(
     (*weights).set_weight(VarLabel::new(var), RealSemiring(low), RealSemiring(high))
 }
 
+#[no_mangle]
+#[allow(clippy::missing_safety_doc)]
+pub unsafe extern "C" fn wmc_param_complex_set_weight(
+    weights: *mut WmcParams<Complex>,
+    var: u64,
+    low: Complex,
+    high: Complex,
+) {
+    (*weights).set_weight(VarLabel::new(var), low, high)
+}
+
 #[repr(C)]
 #[derive(Clone, Copy)]
 pub struct WeightF64(pub f64, pub f64);
@@ -312,3 +338,29 @@ pub unsafe extern "C" fn weight_f64_lo(w: WeightF64) -> f64 {
 pub unsafe extern "C" fn weight_f64_hi(w: WeightF64) -> f64 {
     w.1
 }
+
+#[repr(C)]
+#[derive(Clone, Copy)]
+pub struct WeightComplex(pub Complex, pub Complex);
+
+#[no_mangle]
+#[allow(clippy::missing_safety_doc)]
+pub unsafe extern "C" fn wmc_param_complex_var_weight(
+    weights: *mut WmcParams<Complex>,
+    var: u64,
+) -> WeightComplex {
+    let (l, h) = (*weights).var_weight(VarLabel::new(var));
+    WeightComplex(*l, *h)
+}
+
+#[no_mangle]
+#[allow(clippy::missing_safety_doc)]
+pub unsafe extern "C" fn weight_complex_lo(w: WeightComplex) -> Complex {
+    w.0
+}
+
+#[no_mangle]
+#[allow(clippy::missing_safety_doc)]
+pub unsafe extern "C" fn weight_complex_hi(w: WeightComplex) -> Complex {
+    w.1
+}

src/util/semirings/complex.rs

@@ -0,0 +1,65 @@
+use super::semiring_traits::*;
+use std::{
+    fmt::{self, Display, Formatter},
+    ops::{Add, Mul, Sub},
+};
+
+#[derive(Debug, Clone, Copy, PartialEq, PartialOrd, Serialize, Deserialize)]
+#[repr(C)]
+pub struct Complex {
+    pub re: f64,
+    pub im: f64,
+}
+
+impl Display for Complex {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        if self.im >= 0. {
+            write!(f, "{}+{}i", self.re, self.im)
+        } else {
+            write!(f, "{}{}i", self.re, self.im)
+        }
+    }
+}
+
+impl Add<Complex> for Complex {
+    type Output = Self;
+
+    fn add(self, rhs: Complex) -> Self::Output {
+        Self {
+            re: self.re + rhs.re,
+            im: self.im + rhs.im,
+        }
+    }
+}
+
+impl Mul<Complex> for Complex {
+    type Output = Self;
+
+    fn mul(self, rhs: Complex) -> Self::Output {
+        Self {
+            re: self.re * rhs.re - self.im * rhs.im,
+            im: self.re * rhs.im + self.im * rhs.re,
+        }
+    }
+}
+
+impl Sub<Complex> for Complex {
+    type Output = Self;
+
+    fn sub(self, rhs: Complex) -> Self::Output {
+        Self {
+            re: self.re - rhs.re,
+            im: self.im - rhs.im,
+        }
+    }
+}
+
+impl Semiring for Complex {
+    fn one() -> Self {
+        Self { re: 1.0, im: 0.0 }
+    }
+
+    fn zero() -> Self {
+        Self { re: 0.0, im: 0.0 }
+    }
+}

src/util/semirings/mod.rs

@@ -1,4 +1,5 @@
 mod boolean;
+mod complex;
 mod expectation;
 mod finitefield;
 mod rational;
@@ -7,6 +8,7 @@ mod semiring_traits;
 mod tropical;
 
 pub use self::boolean::*;
+pub use self::complex::*;
 pub use self::expectation::*;
 pub use self::finitefield::*;
 pub use self::rational::*;