File size: 6,638 Bytes
224e773 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 | use crate::ast::ConstraintProgram;
use std::collections::HashMap;
/// Evaluator for constraint programs.
///
/// The Evaluator executes a compiled ConstraintProgram against a set of variable bindings.
/// Each constraint is tested: if all its requirements pass, evaluation succeeds. If any
/// requirement fails, the "otherwise" action determines the constraint's result (reject = false,
/// accept = true).
///
/// NAND Lowering (Future Enhancement):
/// The current evaluator uses boolean algebra directly. Future versions will lower constraints
/// to NAND gates for cryptographic finality. Mapping:
/// - Predicate(x) → lookup x in bindings
/// - Check(name) → built-in gate or binding lookup
/// - AND of requirements → cascaded NAND implementations
/// - Constraint evaluation → NAND commitment to immutable ledger (WORM)
pub struct Evaluator {
pub program: ConstraintProgram,
}
impl Evaluator {
pub fn new(program: ConstraintProgram) -> Self {
Self { program }
}
/// Evaluate the constraint program against provided bindings.
///
/// Returns Ok(true) if all constraints pass, Ok(false) if any fails.
/// Returns Err only on internal evaluation errors.
pub fn evaluate(&self, bindings: &HashMap<String, bool>) -> hyperkitty_core::Result<bool> {
Ok(self.program.evaluate(bindings))
}
/// Evaluate a single constraint by name.
///
/// Useful for debugging or selective constraint testing.
pub fn evaluate_constraint(
&self,
name: &str,
bindings: &HashMap<String, bool>,
) -> hyperkitty_core::Result<bool> {
for constraint in &self.program.constraints {
if constraint.name == name {
return Ok(constraint.evaluate(bindings));
}
}
Err(hyperkitty_core::Error::Custom(
format!("Constraint not found: {}", name)
))
}
/// Count how many constraints pass.
pub fn count_passing(&self, bindings: &HashMap<String, bool>) -> usize {
self.program
.constraints
.iter()
.filter(|c| c.evaluate(bindings))
.count()
}
/// Get detailed evaluation report for debugging.
pub fn report(&self, bindings: &HashMap<String, bool>) -> String {
let mut report = String::new();
report.push_str(&format!(
"Constraint Evaluation Report ({} constraints)\n",
self.program.constraints.len()
));
report.push_str(&"=".repeat(60));
report.push('\n');
for constraint in &self.program.constraints {
let result = constraint.evaluate(bindings);
let status = if result { "PASS" } else { "FAIL" };
report.push_str(&format!(
" [{}] {}: {} (otherwise: {:?})\n",
status, constraint.name, constraint.param, constraint.otherwise
));
for req in &constraint.requires {
report.push_str(&format!(" - {:?}\n", req));
}
}
report.push_str(&"=".repeat(60));
report.push('\n');
report.push_str(&format!(
"Overall: {}/{} constraints passed\n",
self.count_passing(bindings),
self.program.constraints.len()
));
report
}
}
impl Default for Evaluator {
fn default() -> Self {
Self {
program: ConstraintProgram::new(),
}
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::ast::{Constraint, OtherwiseAction, Requirement};
#[test]
fn test_evaluator_all_pass() {
let mut prog = ConstraintProgram::new();
let mut c = Constraint::new("test".to_string(), "msg".to_string(), OtherwiseAction::Reject);
c.add_requirement(Requirement::Check("always_true".to_string()));
prog.add_constraint(c);
let evaluator = Evaluator::new(prog);
let bindings = HashMap::new();
assert!(evaluator.evaluate(&bindings).unwrap());
}
#[test]
fn test_evaluator_one_fails() {
let mut prog = ConstraintProgram::new();
let mut c1 = Constraint::new("c1".to_string(), "msg".to_string(), OtherwiseAction::Reject);
c1.add_requirement(Requirement::Check("always_true".to_string()));
prog.add_constraint(c1);
let mut c2 = Constraint::new("c2".to_string(), "msg".to_string(), OtherwiseAction::Reject);
c2.add_requirement(Requirement::Check("always_false".to_string()));
prog.add_constraint(c2);
let evaluator = Evaluator::new(prog);
let bindings = HashMap::new();
assert!(!evaluator.evaluate(&bindings).unwrap());
}
#[test]
fn test_evaluate_single_constraint() {
let mut prog = ConstraintProgram::new();
let mut c1 = Constraint::new("first".to_string(), "msg".to_string(), OtherwiseAction::Reject);
c1.add_requirement(Requirement::Check("always_true".to_string()));
prog.add_constraint(c1);
let mut c2 = Constraint::new("second".to_string(), "msg".to_string(), OtherwiseAction::Reject);
c2.add_requirement(Requirement::Check("always_false".to_string()));
prog.add_constraint(c2);
let evaluator = Evaluator::new(prog);
let bindings = HashMap::new();
assert!(evaluator.evaluate_constraint("first", &bindings).unwrap());
assert!(!evaluator.evaluate_constraint("second", &bindings).unwrap());
}
#[test]
fn test_count_passing() {
let mut prog = ConstraintProgram::new();
for i in 0..3 {
let mut c = Constraint::new(
format!("c{}", i),
"msg".to_string(),
OtherwiseAction::Reject,
);
c.add_requirement(Requirement::Check("always_true".to_string()));
prog.add_constraint(c);
}
let evaluator = Evaluator::new(prog);
let bindings = HashMap::new();
assert_eq!(evaluator.count_passing(&bindings), 3);
}
#[test]
fn test_evaluator_report() {
let mut prog = ConstraintProgram::new();
let mut c = Constraint::new("test".to_string(), "msg".to_string(), OtherwiseAction::Reject);
c.add_requirement(Requirement::Check("always_true".to_string()));
prog.add_constraint(c);
let evaluator = Evaluator::new(prog);
let bindings = HashMap::new();
let report = evaluator.report(&bindings);
assert!(report.contains("Constraint Evaluation Report"));
assert!(report.contains("test"));
assert!(report.contains("PASS"));
}
}
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