Files
scryer-prolog/src/machine/parsed_results.rs
2024-08-16 00:34:46 -03:00

629 lines
22 KiB
Rust

use crate::atom_table::*;
use crate::heap_iter::{stackful_post_order_iter, NonListElider};
use crate::machine::{F64Offset, F64Ptr, Fixnum, HeapCellValueTag};
use crate::parser::ast::{Var, VarPtr};
use dashu::*;
use indexmap::IndexMap;
use ordered_float::OrderedFloat;
use std::cmp::Ordering;
use std::collections::BTreeMap;
use std::collections::HashMap;
use std::fmt::Display;
use std::fmt::Write;
use std::iter::FromIterator;
use super::Machine;
use super::{HeapCellValue, Number};
pub type QueryResult = Result<QueryResolution, String>;
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum QueryResolution {
True,
False,
Matches(Vec<QueryMatch>),
}
pub fn write_prolog_value_as_json<W: Write>(
writer: &mut W,
value: &Value,
) -> Result<(), std::fmt::Error> {
match value {
Value::Integer(i) => write!(writer, "{}", i),
Value::Float(f) => write!(writer, "{}", f),
Value::Rational(r) => write!(writer, "{}", r),
Value::Atom(a) => writer.write_str(a.as_str()),
Value::String(s) => {
if let Err(_e) = serde_json::from_str::<serde_json::Value>(s.as_str()) {
//treat as string literal
//escape double quotes
write!(
writer,
"\"{}\"",
s.replace('\"', "\\\"")
.replace('\n', "\\n")
.replace('\t', "\\t")
.replace('\r', "\\r")
)
} else {
//return valid json string
writer.write_str(s)
}
}
Value::List(l) => {
writer.write_char('[')?;
if let Some((first, rest)) = l.split_first() {
write_prolog_value_as_json(writer, first)?;
for other in rest {
writer.write_char(',')?;
write_prolog_value_as_json(writer, other)?;
}
}
writer.write_char(']')
}
Value::Structure(s, l) => {
write!(writer, "\"{}\":[", s.as_str())?;
if let Some((first, rest)) = l.split_first() {
write_prolog_value_as_json(writer, first)?;
for other in rest {
writer.write_char(',')?;
write_prolog_value_as_json(writer, other)?;
}
}
writer.write_char(']')
}
_ => writer.write_str("null"),
}
}
fn write_prolog_match_as_json<W: std::fmt::Write>(
writer: &mut W,
query_match: &QueryMatch,
) -> Result<(), std::fmt::Error> {
writer.write_char('{')?;
let mut iter = query_match.bindings.iter();
if let Some((k, v)) = iter.next() {
write!(writer, "\"{k}\":")?;
write_prolog_value_as_json(writer, v)?;
for (k, v) in iter {
write!(writer, ",\"{k}\":")?;
write_prolog_value_as_json(writer, v)?;
}
}
writer.write_char('}')
}
impl Display for QueryResolution {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
match self {
QueryResolution::True => f.write_str("true"),
QueryResolution::False => f.write_str("false"),
QueryResolution::Matches(matches) => {
f.write_char('[')?;
if let Some((first, rest)) = matches.split_first() {
write_prolog_match_as_json(f, first)?;
for other in rest {
f.write_char(',')?;
write_prolog_match_as_json(f, other)?;
}
}
f.write_char(']')
}
}
}
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct QueryMatch {
pub bindings: BTreeMap<String, Value>,
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum QueryResolutionLine {
True,
False,
Match(BTreeMap<String, Value>),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum Value {
Integer(Integer),
Rational(Rational),
Float(OrderedFloat<f64>),
Atom(String),
String(String),
List(Vec<Value>),
Structure(String, Vec<Value>),
Var(String),
}
/// This is an auxiliary function to turn a count into names of anonymous variables like _A, _B,
/// _AB, etc...
fn count_to_letter_code(mut count: usize) -> String {
let mut letters = Vec::new();
loop {
let letter_idx = (count % 26) as u32;
letters.push(char::from_u32('A' as u32 + letter_idx).unwrap());
count /= 26;
if count == 0 {
break;
}
}
letters.into_iter().chain("_".chars()).rev().collect()
}
impl Value {
pub(crate) fn from_heapcell(
machine: &mut Machine,
heap_cell: HeapCellValue,
var_names: &mut IndexMap<HeapCellValue, VarPtr>,
) -> Self {
// Adapted from MachineState::read_term_from_heap
let mut term_stack = vec![];
let iter = stackful_post_order_iter::<NonListElider>(
&mut machine.machine_st.heap,
&mut machine.machine_st.stack,
heap_cell,
);
let mut anon_count: usize = 0;
let var_ptr_cmp = |a, b| match a {
Var::Named(name_a) => match b {
Var::Named(name_b) => name_a.cmp(&name_b),
_ => Ordering::Less,
},
_ => match b {
Var::Named(_) => Ordering::Greater,
_ => Ordering::Equal,
},
};
for addr in iter {
let addr = unmark_cell_bits!(addr);
read_heap_cell!(addr,
(HeapCellValueTag::Lis) => {
let tail = term_stack.pop().unwrap();
let head = term_stack.pop().unwrap();
let list = match tail {
Value::Atom(atom) if atom == "[]" => match head {
Value::Atom(ref a) if a.chars().collect::<Vec<_>>().len() == 1 => {
// Handle lists of char as strings
Value::String(a.to_string())
}
_ => Value::List(vec![head]),
},
Value::List(elems) if elems.is_empty() => match head {
Value::Atom(ref a) if a.chars().collect::<Vec<_>>().len() == 1 => {
// Handle lists of char as strings
Value::String(a.to_string())
},
_ => Value::List(vec![head]),
},
Value::List(mut elems) => {
elems.insert(0, head);
Value::List(elems)
},
Value::String(mut elems) => match head {
Value::Atom(ref a) if a.chars().collect::<Vec<_>>().len() == 1 => {
// Handle lists of char as strings
elems.insert(0, a.chars().next().unwrap());
Value::String(elems)
},
_ => {
let mut elems: Vec<Value> = elems
.chars()
.map(|x| Value::Atom(x.into()))
.collect();
elems.insert(0, head);
Value::List(elems)
}
},
_ => Value::Structure(".".into(), vec![head, tail]),
};
term_stack.push(list);
}
(HeapCellValueTag::Var | HeapCellValueTag::AttrVar | HeapCellValueTag::StackVar) => {
let var = var_names.get(&addr).map(|x| x.borrow().clone());
match var {
Some(Var::Named(name)) => term_stack.push(Value::Var(name)),
_ => {
let anon_name = loop {
// Generate a name for the anonymous variable
let anon_name = count_to_letter_code(anon_count);
// Find if this name is already being used
var_names.sort_by(|_, a, _, b| {
var_ptr_cmp(a.borrow().clone(), b.borrow().clone())
});
let binary_result = var_names.binary_search_by(|_,a| {
let var_ptr = Var::Named(anon_name.clone());
var_ptr_cmp(a.borrow().clone(), var_ptr.clone())
});
match binary_result {
Ok(_) => anon_count += 1, // Name already used
Err(_) => {
// Name not used, assign it to this variable
let var_ptr = VarPtr::from(Var::Named(anon_name.clone()));
var_names.insert(addr, var_ptr);
break anon_name;
},
}
};
term_stack.push(Value::Var(anon_name));
},
}
}
(HeapCellValueTag::F64, f) => {
term_stack.push(Value::Float(*f));
}
(HeapCellValueTag::Char, c) => {
term_stack.push(Value::Atom(c.into()));
}
(HeapCellValueTag::Fixnum, n) => {
term_stack.push(Value::Integer(n.into()));
}
(HeapCellValueTag::Cons) => {
match Number::try_from(addr) {
Ok(Number::Integer(i)) => term_stack.push(Value::Integer((*i).clone())),
Ok(Number::Rational(r)) => term_stack.push(Value::Rational((*r).clone())),
_ => {}
}
}
(HeapCellValueTag::CStr, s) => {
term_stack.push(Value::String(s.as_str().to_string()));
}
(HeapCellValueTag::Atom, (name, arity)) => {
//let h = iter.focus().value() as usize;
//let mut arity = arity;
// Not sure why/if this is needed.
// Might find out with better testing later.
/*
if iter.heap.len() > h + arity + 1 {
let value = iter.heap[h + arity + 1];
if let Some(idx) = get_structure_index(value) {
// in the second condition, arity == 0,
// meaning idx cannot pertain to this atom
// if it is the direct subterm of a larger
// structure.
if arity > 0 || !iter.direct_subterm_of_str(h) {
term_stack.push(
Term::Literal(Cell::default(), Literal::CodeIndex(idx))
);
arity += 1;
}
}
}
*/
if arity == 0 {
let atom_name = name.as_str().to_string();
if atom_name == "[]" {
term_stack.push(Value::List(vec![]));
} else {
term_stack.push(Value::Atom(atom_name));
}
} else {
let subterms = term_stack
.drain(term_stack.len() - arity ..)
.collect();
term_stack.push(Value::Structure(name.as_str().to_string(), subterms));
}
}
(HeapCellValueTag::PStr, atom) => {
let tail = term_stack.pop().unwrap();
if let Value::Atom(atom) = tail {
if atom == "[]" {
term_stack.push(Value::String(atom.as_str().to_string()));
}
} else {
let mut list: Vec<Value> = atom
.as_str()
.to_string()
.chars()
.map(|x| Value::Atom(x.to_string()))
.collect();
let mut partial_list = Value::Structure(
".".into(),
vec![
list.pop().unwrap(),
tail,
],
);
while let Some(last) = list.pop() {
partial_list = Value::Structure(
".".into(),
vec![
last,
partial_list,
],
);
}
term_stack.push(partial_list);
}
}
// I dont know if this is needed here.
/*
(HeapCellValueTag::PStrLoc, h) => {
let atom = cell_as_atom_cell!(iter.heap[h]).get_name();
let tail = term_stack.pop().unwrap();
term_stack.push(Term::PartialString(
Cell::default(),
atom.as_str().to_owned(),
Box::new(tail),
));
}
*/
_ => {
}
);
}
debug_assert_eq!(term_stack.len(), 1);
term_stack.pop().unwrap()
}
}
impl From<BTreeMap<&str, Value>> for QueryMatch {
fn from(bindings: BTreeMap<&str, Value>) -> Self {
QueryMatch {
bindings: bindings
.into_iter()
.map(|(k, v)| (k.to_string(), v))
.collect::<BTreeMap<_, _>>(),
}
}
}
impl From<BTreeMap<String, Value>> for QueryMatch {
fn from(bindings: BTreeMap<String, Value>) -> Self {
QueryMatch { bindings }
}
}
impl From<Vec<QueryResolutionLine>> for QueryResolution {
fn from(query_result_lines: Vec<QueryResolutionLine>) -> Self {
// If there is only one line, and it is true or false, return that.
if query_result_lines.len() == 1 {
match query_result_lines[0].clone() {
QueryResolutionLine::True => return QueryResolution::True,
QueryResolutionLine::False => return QueryResolution::False,
_ => {}
}
}
// If there is only one line, and it is an empty match, return false.
if query_result_lines.len() == 1 {
if let QueryResolutionLine::Match(m) = query_result_lines[0].clone() {
if m.is_empty() {
return QueryResolution::False;
}
}
}
// If there is at least one line with true and no matches, return true.
if query_result_lines
.iter()
.any(|l| l == &QueryResolutionLine::True)
&& !query_result_lines
.iter()
.any(|l| matches!(l, QueryResolutionLine::Match(_)))
{
return QueryResolution::True;
}
// If there is at least one match, return all matches.
let all_matches = query_result_lines
.into_iter()
.filter(|l| matches!(l, QueryResolutionLine::Match(_)))
.map(|l| match l {
QueryResolutionLine::Match(m) => QueryMatch::from(m),
_ => unreachable!(),
})
.collect::<Vec<_>>();
if !all_matches.is_empty() {
return QueryResolution::Matches(all_matches);
}
QueryResolution::False
}
}
impl FromIterator<QueryResolutionLine> for QueryResolution {
fn from_iter<I: IntoIterator<Item = QueryResolutionLine>>(iter: I) -> Self {
// TODO: Probably a good idea to implement From<Vec<QueryResolutionLine>> based on this
// instead.
iter.into_iter().collect::<Vec<_>>().into()
}
}
fn split_response_string(input: &str) -> Vec<String> {
let mut level_bracket = 0;
let mut level_parenthesis = 0;
let mut in_double_quotes = false;
let mut in_single_quotes = false;
let mut start = 0;
let mut result = Vec::new();
for (i, c) in input.chars().enumerate() {
match c {
'[' => level_bracket += 1,
']' => level_bracket -= 1,
'(' => level_parenthesis += 1,
')' => level_parenthesis -= 1,
'"' => in_double_quotes = !in_double_quotes,
'\'' => in_single_quotes = !in_single_quotes,
',' if level_bracket == 0
&& level_parenthesis == 0
&& !in_double_quotes
&& !in_single_quotes =>
{
result.push(input[start..i].trim().to_string());
start = i + 1;
}
_ => {}
}
}
result.push(input[start..].trim().to_string());
result
}
fn split_key_value_pairs(input: &str) -> Vec<(String, String)> {
let items = split_response_string(input);
let mut result = Vec::new();
for item in items {
let parts: Vec<&str> = item.splitn(2, '=').collect();
if parts.len() == 2 {
let key = parts[0].trim().to_string();
let value = parts[1].trim().to_string();
result.push((key, value));
}
}
result
}
fn parse_prolog_response(input: &str) -> HashMap<String, String> {
let mut map: HashMap<String, String> = HashMap::new();
// Use regex to match strings including commas inside them
for result in split_key_value_pairs(input) {
let key = result.0;
let value = result.1;
// cut off at given characters/strings:
let value = value.split('\n').next().unwrap().to_string();
let value = value.split(' ').next().unwrap().to_string();
let value = value.split('\t').next().unwrap().to_string();
let value = value.split("error").next().unwrap().to_string();
map.insert(key, value);
}
map
}
impl TryFrom<String> for QueryResolutionLine {
type Error = ();
fn try_from(string: String) -> Result<Self, Self::Error> {
match string.as_str() {
"true" => Ok(QueryResolutionLine::True),
"false" => Ok(QueryResolutionLine::False),
_ => Ok(QueryResolutionLine::Match(
parse_prolog_response(&string)
.iter()
.map(|(k, v)| -> Result<(String, Value), ()> {
let key = k.to_string();
let value = v.to_string();
Ok((key, Value::try_from(value)?))
})
.filter_map(Result::ok)
.collect::<BTreeMap<_, _>>(),
)),
}
}
}
fn split_nested_list(input: &str) -> Vec<String> {
let mut level = 0;
let mut start = 0;
let mut result = Vec::new();
for (i, c) in input.chars().enumerate() {
match c {
'[' => level += 1,
']' => level -= 1,
',' if level == 0 => {
result.push(input[start..i].trim().to_string());
start = i + 1;
}
_ => {}
}
}
result.push(input[start..].trim().to_string());
result
}
impl TryFrom<String> for Value {
type Error = ();
fn try_from(string: String) -> Result<Self, Self::Error> {
let trimmed = string.trim();
if let Ok(float_value) = string.parse::<f64>() {
Ok(Value::Float(OrderedFloat(float_value)))
} else if let Ok(int_value) = string.parse::<i128>() {
Ok(Value::Integer(int_value.into()))
} else if trimmed.starts_with('\'') && trimmed.ends_with('\'')
|| trimmed.starts_with('"') && trimmed.ends_with('"')
{
Ok(Value::String(trimmed[1..trimmed.len() - 1].into()))
} else if trimmed.starts_with('[') && trimmed.ends_with(']') {
let split = split_nested_list(&trimmed[1..trimmed.len() - 1]);
let values = split
.into_iter()
.map(Value::try_from)
.collect::<Result<Vec<_>, _>>()?;
Ok(Value::List(values))
} else if trimmed.starts_with('{') && trimmed.ends_with('}') {
let iter = trimmed[1..trimmed.len() - 1].split(',');
let mut values = vec![];
for value in iter {
let items: Vec<_> = value.split(':').collect();
if items.len() == 2 {
let _key = items[0].to_string();
let value = items[1].to_string();
values.push(Value::try_from(value)?);
}
}
Ok(Value::Structure("{}".into(), values))
} else if trimmed.starts_with("<<") && trimmed.ends_with(">>") {
let iter = trimmed[2..trimmed.len() - 2].split(',');
let mut values = vec![];
for value in iter {
let items: Vec<_> = value.split(':').collect();
if items.len() == 2 {
let _key = items[0].to_string();
let value = items[1].to_string();
values.push(Value::try_from(value)?);
}
}
Ok(Value::Structure("<<>>".into(), values))
} else if !trimmed.contains(',') && !trimmed.contains('\'') && !trimmed.contains('"') {
Ok(Value::String(trimmed.into()))
} else {
Err(())
}
}
}
impl From<&str> for Value {
fn from(str: &str) -> Self {
Value::String(str.to_string())
}
}