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Simplify Alternative data structure

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Most of the subfields are duplicated on Subpattern so just use that
directly
This commit is contained in:
greg 2019-07-30 01:33:09 -07:00
parent 37c77d93d7
commit ee87695626
2 changed files with 20 additions and 19 deletions
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14
schala-lang/language/src/eval.rs
View File

@ -425,15 +425,15 @@ impl<'a> State<'a> {
let cond = self.expression(Node::Expr(cond))?; let cond = self.expression(Node::Expr(cond))?;
for alt in alternatives { for alt in alternatives {
// no matter what type of condition we have, ignore alternative if the guard evaluates false // no matter what type of condition we have, ignore alternative if the guard evaluates false
if !self.guard_passes(&alt.guard, &cond)? { if !self.guard_passes(&alt.matchable.guard, &cond)? {
continue; continue;
} }
match cond { match cond {
Node::PrimObject { ref tag, ref items, .. } => { Node::PrimObject { ref tag, ref items, .. } => {
if alt.tag.map(|t| t == *tag).unwrap_or(true) { if alt.matchable.tag.map(|t| t == *tag).unwrap_or(true) {
let mut inner_state = self.new_frame(items, &alt.bound_vars); let mut inner_state = self.new_frame(items, &alt.matchable.bound_vars);
if all_subpatterns_pass(&mut inner_state, &alt.subpatterns, items)? { if all_subpatterns_pass(&mut inner_state, &alt.matchable.subpatterns, items)? {
return inner_state.block(alt.item); return inner_state.block(alt.item);
} else { } else {
continue; continue;
@ -441,15 +441,15 @@ impl<'a> State<'a> {
} }
}, },
Node::PrimTuple { ref items } => { Node::PrimTuple { ref items } => {
let mut inner_state = self.new_frame(items, &alt.bound_vars); let mut inner_state = self.new_frame(items, &alt.matchable.bound_vars);
if all_subpatterns_pass(&mut inner_state, &alt.subpatterns, items)? { if all_subpatterns_pass(&mut inner_state, &alt.matchable.subpatterns, items)? {
return inner_state.block(alt.item); return inner_state.block(alt.item);
} else { } else {
continue; continue;
} }
}, },
Node::Expr(ref _e) => { Node::Expr(ref _e) => {
if let None = alt.tag { if let None = alt.matchable.tag {
return self.block(alt.item) return self.block(alt.item)
} }
} }

25
schala-lang/language/src/reduced_ast.rs
View File

@ -60,10 +60,7 @@ pub type BoundVars = Vec<Option<Rc<String>>>; //remember that order matters here
#[derive(Debug, Clone)] #[derive(Debug, Clone)]
pub struct Alternative { pub struct Alternative {
pub tag: Option<usize>, pub matchable: Subpattern,
pub subpatterns: Vec<Option<Subpattern>>,
pub guard: Option<Expr>,
pub bound_vars: BoundVars,
pub item: Vec<Stmt>, pub item: Vec<Stmt>,
} }
@ -201,10 +198,12 @@ fn reduce_if_expression(discriminator: &Discriminator, body: &IfExpressionBody,
let alternatives = vec![ let alternatives = vec![
pat.to_alternative(then_clause, symbol_table), pat.to_alternative(then_clause, symbol_table),
Alternative { Alternative {
tag: None, matchable: Subpattern {
subpatterns: vec![], tag: None,
bound_vars: vec![], subpatterns: vec![],
guard: None, bound_vars: vec![],
guard: None,
},
item: else_clause item: else_clause
}, },
]; ];
@ -278,10 +277,12 @@ impl Pattern {
fn to_alternative(&self, item: Vec<Stmt>, symbol_table: &SymbolTable) -> Alternative { fn to_alternative(&self, item: Vec<Stmt>, symbol_table: &SymbolTable) -> Alternative {
let s = self.to_subpattern(symbol_table); let s = self.to_subpattern(symbol_table);
Alternative { Alternative {
tag: s.tag, matchable: Subpattern {
subpatterns: s.subpatterns, tag: s.tag,
bound_vars: s.bound_vars, subpatterns: s.subpatterns,
guard: s.guard, bound_vars: s.bound_vars,
guard: s.guard,
},
item item
} }
} }