lib-laddertypes/src/morphism.rs

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use {
crate::{
subtype_unify, sugar::SugaredTypeTerm, unification::UnificationProblem, unparser::*, TypeDict, TypeID, TypeTerm
},
std::{collections::HashMap, u64}
};
//<<<<>>>><<>><><<>><<<*>>><<>><><<>><<<<>>>>\\
#[derive(Clone, PartialEq, Eq, Debug)]
pub struct MorphismType {
pub src_type: TypeTerm,
pub dst_type: TypeTerm,
}
impl MorphismType {
pub fn normalize(self) -> Self {
MorphismType {
src_type: self.src_type.normalize().param_normalize(),
dst_type: self.dst_type.normalize().param_normalize()
}
}
}
//<<<<>>>><<>><><<>><<<*>>><<>><><<>><<<<>>>>\\
pub trait Morphism : Sized {
fn get_type(&self) -> MorphismType;
fn map_morphism(&self, seq_type: TypeTerm) -> Option< Self >;
fn weight(&self) -> u64 {
1
}
}
//<<<<>>>><<>><><<>><<<*>>><<>><><<>><<<<>>>>\\
#[derive(Clone, Debug, PartialEq)]
pub struct MorphismInstance<M: Morphism + Clone> {
pub halo: TypeTerm,
pub m: M,
pub σ: HashMap<TypeID, TypeTerm>
}
impl<M: Morphism + Clone> MorphismInstance<M> {
pub fn get_type(&self) -> MorphismType {
MorphismType {
src_type: TypeTerm::Ladder(vec![
self.halo.clone(),
self.m.get_type().src_type.clone()
]).apply_substitution(&|k| self.σ.get(k).cloned())
.clone(),
dst_type: TypeTerm::Ladder(vec![
self.halo.clone(),
self.m.get_type().dst_type.clone()
]).apply_substitution(&|k| self.σ.get(k).cloned())
.clone()
}.normalize()
}
}
//<<<<>>>><<>><><<>><<<*>>><<>><><<>><<<<>>>>\\
#[derive(Clone)]
pub struct MorphismPath<M: Morphism + Clone> {
pub weight: u64,
pub cur_type: TypeTerm,
pub morphisms: Vec< MorphismInstance<M> >
}
//<<<<>>>><<>><><<>><<<*>>><<>><><<>><<<<>>>>\\
#[derive(Clone)]
pub struct MorphismBase<M: Morphism + Clone> {
morphisms: Vec< M >,
seq_types: Vec< TypeTerm >
}
impl<M: Morphism + Clone> MorphismBase<M> {
pub fn new(seq_types: Vec<TypeTerm>) -> Self {
MorphismBase {
morphisms: Vec::new(),
seq_types
}
}
pub fn add_morphism(&mut self, m: M) {
self.morphisms.push( m );
}
pub fn enum_direct_morphisms(&self, src_type: &TypeTerm)
-> Vec< MorphismInstance<M> >
{
let mut dst_types = Vec::new();
for m in self.morphisms.iter() {
if let Ok((halo, σ)) = crate::unification::subtype_unify(
&src_type.clone().param_normalize(),
&m.get_type().src_type.param_normalize(),
) {
dst_types.push(MorphismInstance{ halo, m: m.clone(), σ });
}
}
dst_types
}
pub fn enum_map_morphisms(&self, src_type: &TypeTerm)
-> Vec< MorphismInstance<M> > {
let src_type = src_type.clone().param_normalize();
let mut dst_types = Vec::new();
// Check if we have a List type, and if so, see what the Item type is
// TODO: function for generating fresh variables
let item_variable = TypeID::Var(800);
for seq_type in self.seq_types.iter() {
if let Ok((halo, σ)) = crate::unification::subtype_unify(
&src_type,
&TypeTerm::App(vec![
seq_type.clone(),
TypeTerm::TypeID(item_variable)
])
) {
let src_item_type = σ.get(&item_variable).expect("var not in unificator").clone();
for item_morph_inst in self.enum_morphisms( &src_item_type ) {
let mut dst_halo_ladder = vec![ halo.clone() ];
if item_morph_inst.halo != TypeTerm::unit() {
dst_halo_ladder.push(
TypeTerm::App(vec![
seq_type.clone().get_lnf_vec().first().unwrap().clone(),
item_morph_inst.halo.clone()
]));
}
if let Some( map_morph ) = item_morph_inst.m.map_morphism( seq_type.clone() ) {
dst_types.push(
MorphismInstance {
halo: TypeTerm::Ladder(dst_halo_ladder).normalize(),
m: map_morph,
σ: item_morph_inst.σ
}
);
} else {
eprintln!("could not get map morphism");
}
}
}
}
dst_types
}
pub fn enum_morphisms(&self, src_type: &TypeTerm) -> Vec< MorphismInstance<M> > {
let mut dst_types = Vec::new();
dst_types.append(&mut self.enum_direct_morphisms(src_type));
dst_types.append(&mut self.enum_map_morphisms(src_type));
dst_types
}
/* try to find shortest morphism-path for a given type
*/
pub fn find_morphism_path(&self, ty: MorphismType
/*, type_dict: &mut impl TypeDict*/
)
-> Option< Vec<MorphismInstance<M>> >
{
let ty = ty.normalize();
let mut queue = vec![
MorphismPath { weight: 0, cur_type: ty.src_type.clone(), morphisms: vec![] }
];
while ! queue.is_empty() {
queue.sort_by( |p1,p2| p2.weight.cmp(&p1.weight));
if let Some(mut cur_path) = queue.pop() {
if let Ok((halo, σ)) = crate::unification::subtype_unify( &cur_path.cur_type, &ty.dst_type ) {
// found path
for n in cur_path.morphisms.iter_mut() {
let mut new_σ = HashMap::new();
for (k,v) in σ.iter() {
new_σ.insert(
k.clone(),
v.clone().apply_substitution(&|k| σ.get(k).cloned()).clone()
);
}
for (k,v) in n.σ.iter() {
new_σ.insert(
k.clone(),
v.clone().apply_substitution(&|k| σ.get(k).cloned()).clone()
);
}
n.σ = new_σ;
}
return Some(cur_path.morphisms);
}
//eprintln!("cur path (w ={}) : @ {}", cur_path.weight, cur_path.cur_type.clone().sugar(type_dict).pretty(type_dict, 0) );
for next_morph_inst in self.enum_morphisms(&cur_path.cur_type) {
let dst_type = next_morph_inst.get_type().dst_type;
let mut creates_loop = false;
let mut new_path = cur_path.clone();
for n in new_path.morphisms.iter_mut() {
let mut new_σ = HashMap::new();
for (k,v) in n.σ.iter() {
new_σ.insert(
k.clone(),
v.clone().apply_substitution(&|k| next_morph_inst.σ.get(k).cloned()).clone()
);
}
for (k,v) in next_morph_inst.σ.iter() {
new_σ.insert(
k.clone(),
v.clone().apply_substitution(&|k| next_morph_inst.σ.get(k).cloned()).clone()
);
}
n.σ = new_σ;
}
for m in new_path.morphisms.iter() {
if m.get_type().src_type == dst_type {
creates_loop = true;
//eprintln!("creates loop..");
break;
}
}
if ! creates_loop {
/*eprintln!("next morph ? \n {}\n--> {} ",
next_morph_inst.get_type().src_type.sugar(type_dict).pretty(type_dict, 0),
next_morph_inst.get_type().dst_type.sugar(type_dict).pretty(type_dict, 0)
);
eprintln!("....take!\n :: halo = {}\n :: σ = {:?}", next_morph_inst.halo.clone().sugar(type_dict).pretty(type_dict, 0), next_morph_inst.σ);
*/
new_path.weight += next_morph_inst.m.weight();
new_path.cur_type = dst_type;
new_path.morphisms.push(next_morph_inst);
queue.push(new_path);
}
}
}
}
None
}
pub fn find_direct_morphism(&self,
ty: &MorphismType,
dict: &mut impl TypeDict
) -> Option< MorphismInstance<M> > {
eprintln!("find direct morph");
for m in self.morphisms.iter() {
let ty = ty.clone().normalize();
let morph_type = m.get_type().normalize();
eprintln!("find direct morph:\n {} <= {}",
dict.unparse(&ty.src_type), dict.unparse(&morph_type.src_type),
);
if let Ok((halo, σ)) = subtype_unify(&ty.src_type, &morph_type.src_type) {
eprintln!("halo: {}", dict.unparse(&halo));
let dst_type = TypeTerm::Ladder(vec![
halo.clone(),
morph_type.dst_type.clone()
]);
eprintln!("-----------> {} <= {}",
dict.unparse(&dst_type), dict.unparse(&ty.dst_type)
);
/*
let unification_problem = UnificationProblem::new(
vec![
( ty.src_type, morph_type.src_type ),
( morph_type.dst_type, ty.dst_type )
]
);*/
if let Ok((halo2, σ2)) = subtype_unify(&dst_type, &ty.dst_type) {
eprintln!("match. halo2 = {}", dict.unparse(&halo2));
return Some(MorphismInstance {
m: m.clone(),
halo: halo2,
σ,
});
}
}
}
None
}
pub fn find_map_morphism(&self, ty: &MorphismType, dict: &mut impl TypeDict) -> Option< MorphismInstance<M> > {
for seq_type in self.seq_types.iter() {
if let Ok((halo, σ)) = UnificationProblem::new(vec![
(ty.src_type.clone().param_normalize(),
TypeTerm::App(vec![ seq_type.clone(), TypeTerm::TypeID(TypeID::Var(100)) ])),
(TypeTerm::App(vec![ seq_type.clone(), TypeTerm::TypeID(TypeID::Var(101)) ]),
ty.dst_type.clone().param_normalize()),
]).solve_subtype() {
// TODO: use real fresh variable names
let item_morph_type = MorphismType {
src_type: σ.get(&TypeID::Var(100)).unwrap().clone(),
dst_type: σ.get(&TypeID::Var(101)).unwrap().clone(),
}.normalize();
//eprintln!("Map Morph: try to find item-morph with type {:?}", item_morph_type);
if let Some(item_morph_inst) = self.find_morphism( &item_morph_type, dict ) {
if let Some( list_morph ) = item_morph_inst.m.map_morphism( seq_type.clone() ) {
return Some( MorphismInstance {
m: list_morph,
σ,
halo
} );
}
}
}
}
None
}
pub fn find_morphism(&self, ty: &MorphismType,
dict: &mut impl TypeDict
)
-> Option< MorphismInstance<M> > {
if let Some(m) = self.find_direct_morphism(ty, dict) {
return Some(m);
}
if let Some(m) = self.find_map_morphism(ty, dict) {
return Some(m);
}
None
}
}
//<<<<>>>><<>><><<>><<<*>>><<>><><<>><<<<>>>>\\