Restructure crate for a nicer interface

src/ast.rs

@@ -0,0 +1,76 @@
+#[derive(PartialEq)]
+pub struct PredicateDeclaration
+{
+	pub name: String,
+	pub arity: usize,
+}
+
+#[derive(PartialEq)]
+pub struct Predicate
+{
+	pub declaration: PredicateDeclaration,
+	pub arguments: Vec<Term>,
+}
+
+#[derive(PartialEq)]
+pub struct Exists
+{
+	pub parameters: Vec<VariableDeclaration>,
+	pub argument: Box<Formula>,
+}
+
+#[derive(PartialEq)]
+pub struct ForAll
+{
+	pub parameters: Vec<VariableDeclaration>,
+	pub argument: Box<Formula>,
+}
+
+#[derive(PartialEq)]
+pub enum Formula
+{
+	Exists(Exists),
+	ForAll(ForAll),
+	Not(Box<Formula>),
+	And(Vec<Box<Formula>>),
+	Or(Vec<Box<Formula>>),
+	Implies(Box<Formula>, Box<Formula>),
+	Biconditional(Box<Formula>, Box<Formula>),
+	Less(Term, Term),
+	LessOrEqual(Term, Term),
+	Greater(Term, Term),
+	GreaterOrEqual(Term, Term),
+	Equal(Term, Term),
+	NotEqual(Term, Term),
+	Boolean(bool),
+	Predicate(Predicate),
+}
+
+#[derive(PartialEq)]
+pub enum Domain
+{
+	Program,
+	Integer,
+}
+
+#[derive(PartialEq)]
+pub struct VariableDeclaration
+{
+	pub name: String,
+	pub domain: Domain,
+}
+
+#[derive(PartialEq)]
+pub enum Term
+{
+	Infimum,
+	Supremum,
+	Integer(i64),
+	Symbolic(String),
+	String(String),
+	Variable(VariableDeclaration),
+	Add(Box<Term>, Box<Term>),
+	Subtract(Box<Term>, Box<Term>),
+	Multiply(Box<Term>, Box<Term>),
+	Negative(Box<Term>),
+}