refactor(language): simplify syntax

3 files changed, 24 insertions, 19 deletions

diff --git a/subprojects/frontend/src/index.tsx b/subprojects/frontend/src/index.tsx
index 0165d7c1..a40f1762 100644
--- a/subprojects/frontend/src/index.tsx
+++ b/subprojects/frontend/src/index.tsx
@@ -10,29 +10,29 @@ const initialValue = `class Family {
 }
 
 class Person {
-    refers Person[] children opposite parent
-    refers Person[0..1] parent opposite children
+    Person[] children opposite parent
+    Person[0..1] parent opposite children
     int age
-    refers TaxStatus taxStatus
+    TaxStatus taxStatus
 }
 
 enum TaxStatus {
-    child, student, adult, retired
+    CHILD, STUDENT, ADULT, RETIRED
 }
 
 % A child cannot have any dependents.
 pred invalidTaxStatus(Person p) <->
-    taxStatus(p, child),
+    taxStatus(p, CHILD),
     children(p, _q)
 ;
     parent(p, q),
     age(q) < age(p)
 ;
-    taxStatus(p, retired),
+    taxStatus(p, RETIRED),
     parent(p, q),
-    !taxStatus(q, retired).
+    !taxStatus(q, RETIRED).
 
-individual family.
+indiv family.
 Family(family).
 members(family, anne).
 members(family, bob).
@@ -40,9 +40,9 @@ members(family, ciri).
 children(anne, ciri).
 ?children(bob, ciri).
 default children(ciri, *): false.
-taxStatus(anne, adult).
-age(bob) in 21..35.
-age(ciri) = 10.
+taxStatus(anne, ADULT).
+age(bob): 21..35.
+age(ciri): 10.
 
 scope Family = 1, Person += 5..10.
 `;
diff --git a/subprojects/frontend/src/language/problem.grammar b/subprojects/frontend/src/language/problem.grammar
index 7c4098d5..c2410913 100644
--- a/subprojects/frontend/src/language/problem.grammar
+++ b/subprojects/frontend/src/language/problem.grammar
@@ -3,6 +3,7 @@
 @external prop implicitCompletion from './props'
 
 @precedence {
+  reference @cut,
   prefix,
   exponential @right,
   multiplicative @left,
@@ -47,10 +48,10 @@ statement {
   Assertion {
     kw<"default">? (NotOp | UnknownOp)? RelationName
     ParameterList<AssertionArgument>
-    (":" LogicValue | ("=" | kw<"in">) Expr)? "."
+    (":" Expr)? "."
   } |
   IndividualDeclaration {
-    kw<"individual"> sep<",", IndividualNodeName> "."
+    kw<"indiv"> sep<",", IndividualNodeName> "."
   } |
   ScopeDeclaration {
     kw<"scope"> sep<",", ScopeElement> "."
@@ -58,7 +59,8 @@ statement {
 }
 
 FeatureDeclaration {
-  (ReferenceKind | PrimitiveType | kw<"bool">) RelationName
+  // The @cut helps disambiguate silly cases like `contains contains`
+  (ReferenceKind !reference | PrimitiveType | kw<"bool">)? RelationName
   ("[" Multiplicity? "]")?
   RelationName
   (kw<"opposite"> RelationName)?
@@ -90,7 +92,7 @@ BinaryExpr {
 }
 
 UnaryExpr {
-  !prefix ("+" | "-" | "!" | "#" | Modality) Expr
+  !prefix ("+" | "-" | "!" | kw<"count"> | Modality) Expr
 }
 
 Aggregation {
@@ -109,7 +111,7 @@ Atom { RelationName "+"? ParameterList<Expr> }
 
 AssertionArgument { NodeName | StarArgument }
 
-Constant { Real | String | StarMult }
+Constant { Real | String | StarMult | LogicValue }
 
 ReferenceKind {
   kw<"refers"> | ckw<"contains"> | kw<"container">
@@ -199,7 +201,10 @@ sep1<separator, content> { content (separator content)* }
     "\"" (![\\"\n] | "\\" (![\n] | "\n"))* "\""
   }
 
-  SymbolicComparisonOp { ">" | ">=" | "<" | "<=" | "==" | "!=" }
+  SymbolicComparisonOp {
+    ">" | ">=" | "<" | "<=" | "==" | "!=" |
+    "<:" | ":>" | "===" | "!=="
+  }
 
   NotOp { "!" }
 
diff --git a/subprojects/frontend/src/language/problemLanguageSupport.ts b/subprojects/frontend/src/language/problemLanguageSupport.ts
index 2a973c93..497030e2 100644
--- a/subprojects/frontend/src/language/problemLanguageSupport.ts
+++ b/subprojects/frontend/src/language/problemLanguageSupport.ts
@@ -21,12 +21,12 @@ const parserWithMetadata = parser.configure({
     styleTags({
       LineComment: t.lineComment,
       BlockComment: t.blockComment,
-      'problem class enum pred individual scope': t.definitionKeyword,
+      'problem class enum pred indiv scope': t.definitionKeyword,
       'abstract extends refers contains container opposite': t.modifier,
       'default error contained containment': t.modifier,
       'true false unknown error': t.keyword,
       'int real string bool': t.keyword,
-      'may must current': t.operatorKeyword,
+      'may must current count': t.operatorKeyword,
       'sum prod min max in': t.operatorKeyword,
       // 'new delete': t.keyword,
       NotOp: t.operator,