Support Record patterns

schala-lang/language/src/parsing/mod.rs

@@ -1123,7 +1123,11 @@ impl Parser {
                 let pat = self.pattern()?;
                 (name, pat)
             }
-            _ => (name.clone(), Pattern::Literal(PatternLiteral::StringPattern(name))),
+            _ => {
+                let qualified_identifier =
+                    QualifiedName { id: self.id_store.fresh(), components: vec![name.clone()] };
+                (name, Pattern::VarOrName(qualified_identifier))
+            }
         })
     }
 

schala-lang/language/src/parsing/test.rs

@@ -1099,10 +1099,7 @@ fn pattern_matching() {
             body: bx(IfExpressionBody::SimplePatternMatch {
                 pattern: Pattern::Record(
                     qn!(Something),
-                    vec![
-                        (rc("a"), Pattern::Literal(PatternLiteral::StringPattern(rc("a")))),
-                        (rc("b"), Pattern::VarOrName(qn!(x)))
-                    ]
+                    vec![(rc("a"), Pattern::VarOrName(qn!(a))), (rc("b"), Pattern::VarOrName(qn!(x)))]
                 ),
                 then_case: vec![exst(NatLiteral(4))].into(),
                 else_case: Some(vec![exst(NatLiteral(9))].into()),

schala-lang/language/src/reduced_ir/mod.rs

@@ -1,4 +1,4 @@
-use std::{collections::HashMap, str::FromStr};
+use std::{collections::HashMap, rc::Rc, str::FromStr};
 
 use crate::{
     ast,
@@ -149,10 +149,9 @@ impl<'a, 'b> Reducer<'a, 'b> {
             }),
             NamedStruct { name, fields } => {
                 self.symbol_table.debug();
-                println!("Namedstruct name {} id: {}", name, name.id);
                 let symbol = self.symbol_table.lookup_symbol(&name.id).unwrap();
                 let (tag, type_id) = match symbol.spec() {
-                    SymbolSpec::RecordConstructor { tag, members: _, type_id } => (tag, type_id),
+                    SymbolSpec::RecordConstructor { tag, type_id } => (tag, type_id),
                     e => return Expression::ReductionError(format!("Bad symbol for NamedStruct: {:?}", e)),
                 };
 
@@ -279,7 +278,6 @@ impl<'a, 'b> Reducer<'a, 'b> {
     }
 
     fn prefix(&mut self, prefix: &ast::PrefixOp, arg: &ast::Expression) -> Expression {
-        println!("PREFIX: {:?} and ARG: {:?}", prefix, arg);
         let builtin: Option<Builtin> = TryFrom::try_from(prefix).ok();
         match builtin {
             Some(op) => Expression::Call {
@@ -395,11 +393,27 @@ impl ast::Pattern {
                     spec => return Err(format!("Unexpected VarOrName symbol: {:?}", spec).into()),
                 }
             }
-            ast::Pattern::Record(name, _specified_members /*Vec<(Rc<String>, Pattern)>*/) => {
+            ast::Pattern::Record(name, specified_members) => {
                 let symbol = symbol_table.lookup_symbol(&name.id).unwrap();
-                match symbol.spec() {
-                    SymbolSpec::RecordConstructor { tag: _, members: _, type_id: _ } => unimplemented!(),
-                    spec => return Err(format!("Unexpected Record pattern symbol: {:?}", spec).into()),
+                if let SymbolSpec::RecordConstructor { tag, type_id: _ } = symbol.spec() {
+                    //TODO do this computation from the type_id
+                    /*
+                    if specified_members.iter().any(|(member, _)| !members.contains_key(member)) {
+                        return Err(format!("Unknown key in record pattern").into());
+                    }
+                    */
+
+                    let subpatterns: Result<Vec<(Rc<String>, Pattern)>, PatternError> = specified_members
+                        .iter()
+                        .map(|(name, pat)| {
+                            pat.reduce(symbol_table).map(|reduced_pat| (name.clone(), reduced_pat))
+                        })
+                        .into_iter()
+                        .collect();
+                    let subpatterns = subpatterns?;
+                    Pattern::Record { tag, subpatterns }
+                } else {
+                    return Err(format!("Unexpected Record pattern symbol: {:?}", symbol.spec()).into());
                 }
             }
         })

schala-lang/language/src/reduced_ir/types.rs

@@ -108,6 +108,7 @@ pub struct Alternative {
 #[derive(Debug, Clone)]
 pub enum Pattern {
     Tuple { subpatterns: Vec<Pattern>, tag: Option<u32> },
+    Record { tag: u32, subpatterns: Vec<(Rc<String>, Pattern)> },
     Literal(Literal),
     Ignored,
     Binding(DefId),

schala-lang/language/src/symbol_table/mod.rs

@@ -282,7 +282,7 @@ pub enum SymbolSpec {
     Builtin(Builtin),
     Func,
     DataConstructor { tag: u32, type_id: TypeId },
-    RecordConstructor { tag: u32, members: HashMap<Rc<String>, TypeId>, type_id: TypeId },
+    RecordConstructor { tag: u32, type_id: TypeId },
     GlobalBinding, //Only for global variables, not for function-local ones or ones within a `let` scope context
     LocalVariable,
     FunctionParam(u8),
@@ -515,8 +515,7 @@ impl<'a> SymbolTableRunner<'a> {
             let spec = match &variant.members {
                 type_inference::VariantMembers::Unit => SymbolSpec::DataConstructor { tag, type_id },
                 type_inference::VariantMembers::Tuple(..) => SymbolSpec::DataConstructor { tag, type_id },
-                type_inference::VariantMembers::Record(..) =>
-                    SymbolSpec::RecordConstructor { tag, members: HashMap::new(), type_id },
+                type_inference::VariantMembers::Record(..) => SymbolSpec::RecordConstructor { tag, type_id },
             };
             self.table.add_symbol(id, fqsn, spec);
         }

schala-lang/language/src/tree_walk_eval/evaluator.rs

@@ -261,6 +261,20 @@ impl<'a, 'b> Evaluator<'a, 'b> {
                         _ => false,
                     },
                 },
+                Pattern::Record { tag: pattern_tag, subpatterns } => match scrut {
+                    //TODO several types of possible error here
+                    Primitive::Object { tag, items, ordered_fields: Some(ordered_fields), .. }
+                        if tag == pattern_tag =>
+                        subpatterns.iter().all(|(field_name, subpat)| {
+                            let idx = ordered_fields
+                                .iter()
+                                .position(|field| field.as_str() == field_name.as_ref())
+                                .unwrap();
+                            let item = &items[idx];
+                            matches(item, subpat, scope)
+                        }),
+                    _ => false,
+                },
             }
         }
         let cond = self.expression(cond)?;

schala-lang/language/src/tree_walk_eval/test.rs

@@ -172,6 +172,29 @@ if x {
     eval_assert(&source, expected);
 }
 
+#[test]
+fn record_patterns() {
+    let source = r#"
+type Ara = Kueh { a: Int, b: String } | Morbuk
+
+let alpha = Ara::Kueh { a: 10, b: "sanchez" }
+if alpha {
+    is Ara::Kueh { a, b } then (b, a)
+    is _ then ("nooo", 8888)
+}"#;
+    eval_assert(source, r#"("sanchez", 10)"#);
+
+    let source = r#"
+type Ara = Kueh { a: Int, b: String } | Morbuk
+
+let alpha = Ara::Kueh { a: 10, b: "sanchez" }
+if alpha {
+    is Ara::Kueh { a, b: le_value } then (le_value, (a*2))
+    is _ then ("nooo", 8888)
+}"#;
+    eval_assert(source, r#"("sanchez", 20)"#);
+}
+
 #[test]
 fn if_is_patterns() {
     let source = r#"