From 7c9e80cc1bc328bf51bb2fa4a421ce089e98ea38 Mon Sep 17 00:00:00 2001 From: pca006132 Date: Mon, 4 Jan 2021 14:52:50 +0800 Subject: [PATCH] added inference core --- nac3core/src/inference_core.rs | 200 +++++++++++++++++++++++++++++++++ nac3core/src/lib.rs | 1 + 2 files changed, 201 insertions(+) create mode 100644 nac3core/src/inference_core.rs diff --git a/nac3core/src/inference_core.rs b/nac3core/src/inference_core.rs new file mode 100644 index 00000000..1442a966 --- /dev/null +++ b/nac3core/src/inference_core.rs @@ -0,0 +1,200 @@ +use crate::context::InferenceContext; +use crate::typedef::{TypeEnum::*, *}; +use std::collections::HashMap; + +fn find_subst( + ctx: &InferenceContext, + valuation: &Option<(VariableId, Type)>, + sub: &mut HashMap, + mut a: Type, + mut b: Type, +) -> Result<(), String> { + // TODO: fix error messages later + if let TypeVariable(id) = a.as_ref() { + if let Some((assumption_id, t)) = valuation { + if assumption_id == id { + a = t.clone(); + } + } + } + + let mut substituted = false; + if let TypeVariable(id) = b.as_ref() { + if let Some(c) = sub.get(&id) { + b = c.clone(); + substituted = true; + } + } + + match (a.as_ref(), b.as_ref()) { + (BotType, _) => Ok(()), + (TypeVariable(id_a), TypeVariable(id_b)) => { + if substituted { + return if id_a == id_b { + Ok(()) + } else { + Err("different variables".to_string()) + }; + } + let v_a = ctx.get_variable_def(*id_a); + let v_b = ctx.get_variable_def(*id_b); + if !v_b.bound.is_empty() { + if v_a.bound.is_empty() { + return Err("unbounded a".to_string()); + } else { + let diff: Vec<_> = v_a + .bound + .iter() + .filter(|x| !v_b.bound.contains(x)) + .collect(); + if !diff.is_empty() { + return Err("different domain".to_string()); + } + } + } + sub.insert(*id_b, a.clone()); + Ok(()) + } + (TypeVariable(id_a), _) => { + let v_a = ctx.get_variable_def(*id_a); + if v_a.bound.len() == 1 && v_a.bound[0].as_ref() == b.as_ref() { + Ok(()) + } else { + Err("different domain".to_string()) + } + } + (_, TypeVariable(id_b)) => { + let v_b = ctx.get_variable_def(*id_b); + if v_b.bound.is_empty() || v_b.bound.contains(&a) { + sub.insert(*id_b, a.clone()); + Ok(()) + } else { + Err("different domain".to_string()) + } + } + (_, VirtualClassType(id_b)) => { + let mut parents; + match a.as_ref() { + ClassType(id_a) => { + parents = [*id_a].to_vec(); + } + VirtualClassType(id_a) => { + parents = [*id_a].to_vec(); + } + _ => { + return Err("cannot substitute non-class type into virtual class".to_string()); + } + }; + while !parents.is_empty() { + if *id_b == parents[0] { + return Ok(()); + } + let c = ctx.get_class_def(parents.remove(0)); + parents.extend_from_slice(&c.parents); + } + Err("not subtype".to_string()) + } + (ParametricType(id_a, param_a), ParametricType(id_b, param_b)) => { + if id_a != id_b || param_a.len() != param_b.len() { + Err("different parametric types".to_string()) + } else { + for (x, y) in param_a.iter().zip(param_b.iter()) { + find_subst(ctx, valuation, sub, x.clone(), y.clone())?; + } + Ok(()) + } + } + (_, _) => { + if a == b { + Ok(()) + } else { + Err("not equal".to_string()) + } + } + } +} + +fn resolve_call_rec( + ctx: &InferenceContext, + valuation: &Option<(VariableId, Type)>, + obj: Option, + func: &str, + args: &[Type], +) -> Result, String> { + let mut subst = obj + .as_ref() + .map(|v| v.get_subst(ctx)) + .unwrap_or_else(HashMap::new); + + let fun = match &obj { + Some(obj) => { + let base = match obj.as_ref() { + TypeVariable(id) => { + let v = ctx.get_variable_def(*id); + if v.bound.is_empty() { + return Err("unbounded type var".to_string()); + } + let results: Result, String> = v + .bound + .iter() + .map(|ins| { + resolve_call_rec( + ctx, + &Some((*id, ins.clone())), + Some(ins.clone()), + func, + args.clone(), + ) + }) + .collect(); + let results = results?; + if results.iter().all(|v| v == &results[0]) { + return Ok(results[0].clone()); + } + let mut results = results.iter().zip(v.bound.iter()).map(|(r, ins)| { + r.as_ref() + .map(|v| v.inv_subst(&[(ins.clone(), obj.clone())])) + }); + let first = results.next().unwrap(); + if results.all(|v| v == first) { + return Ok(first); + } else { + return Err("divergent type after substitution".to_string()); + } + } + PrimitiveType(id) => &ctx.get_primitive_def(*id), + ClassType(id) | VirtualClassType(id) => &ctx.get_class_def(*id).base, + ParametricType(id, _) => &ctx.get_parametric_def(*id).base, + _ => return Err("not supported".to_string()), + }; + base.methods.get(func) + } + None => ctx.get_fn_def(func), + } + .ok_or_else(|| "no such function".to_string())?; + + if args.len() != fun.args.len() { + return Err("incorrect parameter number".to_string()); + } + for (a, b) in args.iter().zip(fun.args.iter()) { + find_subst(ctx, valuation, &mut subst, a.clone(), b.clone())?; + } + let result = fun.result.as_ref().map(|v| v.subst(&subst)); + Ok(result.map(|result| { + if let SelfType = result { + obj.unwrap() + } else { + result.into() + } + })) +} + +pub fn resolve_call( + ctx: &InferenceContext, + obj: Option, + func: &str, + args: &[Type], +) -> Result, String> { + resolve_call_rec(ctx, &None, obj, func, args) +} + diff --git a/nac3core/src/lib.rs b/nac3core/src/lib.rs index 73495624..b3fcf1a5 100644 --- a/nac3core/src/lib.rs +++ b/nac3core/src/lib.rs @@ -5,6 +5,7 @@ extern crate num_bigint; extern crate inkwell; extern crate rustpython_parser; +pub mod inference_core; pub mod primitives; pub mod typedef; pub mod context;