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Organized changes into find_optimal_index

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This commit is contained in:
notoria
2020-12-21 12:19:21 +01:00
parent ec2c5a9b2c
commit ecc059bf8b
1 changed files with 41 additions and 36 deletions
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77
src/codegen.rs
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@@ -1,3 +1,4 @@
/// Code generation to WAM-like instructions.
use crate::prolog_parser::ast::*;
use crate::allocator::*;
@@ -857,7 +858,45 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
Ok(code)
}
fn split_predicate(clauses: &Vec<PredicateClause>, optimal_index: usize) -> Vec<(usize, usize)> {
fn find_optimal_index(clauses: &[PredicateClause]) -> usize {
let mut optimal_index = None;
let has_args = match clauses.first() {
Some(clause) => match clause.args() {
Some(args) => !args.is_empty(),
None => false,
},
None => false,
};
if !has_args {
return 0;
}
for clause in clauses.iter() {
let args = clause.args().unwrap();
for (i, arg) in args.iter().enumerate() {
if let Some(optimal_index) = optimal_index {
if i >= optimal_index {
break;
}
}
match **arg {
Term::AnonVar | Term::Var(..) => (),
_ => {
match optimal_index {
Some(ref mut optimal_i) => *optimal_i = i,
None => optimal_index = Some(i),
}
break;
}
}
}
}
match optimal_index {
Some(optimal_index) => optimal_index,
None => 0, // Default to first argument indexing.
}
}
fn split_predicate(clauses: &[PredicateClause], optimal_index: usize) -> Vec<(usize, usize)> {
let mut subseqs = Vec::new();
let mut left_index = 0;
@@ -947,7 +986,6 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
}
let mut code = Vec::new();
code_offsets.add_indices(&mut code, code_body, optimal_index + 1);
Ok(code)
@@ -958,40 +996,7 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
clauses: &'b Vec<PredicateClause>,
) -> Result<Code, ParserError> {
let mut code = Vec::new();
let mut optimal_index = None;
let has_args = match clauses.first() {
Some(clause) => match clause.args() {
Some(args) => !args.is_empty(),
None => false,
},
None => false,
};
if has_args {
for clause in clauses.iter() {
let args = clause.args().unwrap();
for (i, arg) in args.iter().enumerate() {
if let Some(optimal_index) = optimal_index {
if i >= optimal_index {
break;
}
}
match **arg {
Term::AnonVar | Term::Var(..) => (),
_ => {
match optimal_index {
Some(ref mut optimal_i) => *optimal_i = i,
None => optimal_index = Some(i),
}
break;
}
}
}
}
}
let optimal_index = match optimal_index {
Some(optimal_index) => optimal_index,
None => 0, // Default to first argument indexing.
};
let optimal_index = Self::find_optimal_index(&clauses);
let split_pred = Self::split_predicate(&clauses, optimal_index);
let multi_seq = split_pred.len() > 1;