Working example

src/external/conv/to_string.rs

@@ -0,0 +1,35 @@
+
+use std::fmt::Debug;
+use std::hash::Hash;
+
+use crate::external::assertion_error::AssertionError;
+use crate::{atomic_impl, atomic_redirect, externfn_impl};
+use crate::representations::{Primitive, Literal};
+use crate::representations::interpreted::Clause;
+
+/// ToString a clause
+/// 
+/// Next state: [ToString0]
+
+#[derive(Clone)]
+pub struct ToString1;
+externfn_impl!(ToString1, |_: &Self, c: Clause| {Ok(ToString0{c})});
+
+/// Applied ToString function
+/// 
+/// Prev state: [ToString1]
+
+#[derive(Debug, Clone, PartialEq, Hash)]
+pub struct ToString0{ c: Clause }
+atomic_redirect!(ToString0, c);
+atomic_impl!(ToString0, |Self{ c }: &Self| {
+  let literal: &Literal = c.try_into()
+    .map_err(|_| AssertionError::ext(c.clone(), "a literal value"))?;
+  let string = match literal {
+    Literal::Char(c) => c.to_string(),
+    Literal::Uint(i) => i.to_string(),
+    Literal::Num(n) => n.to_string(),
+    Literal::Str(s) => s.clone()
+  };
+  Ok(Clause::P(Primitive::Literal(Literal::Str(string))))
+});