Add missing array API functions and fix BitVec method typos (#8132)

* Initial plan

* Add missing API functions: array_default, array_ext, and fix BitVec typos

Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>

* Add documentation for new array API functions

Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>

* Fix WebAssembly build: Add default() method to LambdaImpl

Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>

src/api/c++/z3++.h

@@ -4085,6 +4085,19 @@ namespace z3 {
         return expr(f.ctx(), r);
     }
 
+    inline expr array_default(expr const & a) {
+        Z3_ast r = Z3_mk_array_default(a.ctx(), a);
+        a.check_error();
+        return expr(a.ctx(), r);
+    }
+
+    inline expr array_ext(expr const & a, expr const & b) {
+        check_context(a, b);
+        Z3_ast r = Z3_mk_array_ext(a.ctx(), a, b);
+        a.check_error();
+        return expr(a.ctx(), r);
+    }
+
 #define MK_EXPR1(_fn, _arg)                     \
     Z3_ast r = _fn(_arg.ctx(), _arg);           \
     _arg.check_error();                         \

src/api/js/src/high-level/high-level.ts

@@ -1324,6 +1324,19 @@ export function createApi(Z3: Z3Core): Z3HighLevel {
       >;
     }
 
+    /**
+     * Create array extensionality index given two arrays with the same sort.
+     * The meaning is given by the axiom:
+     * (=> (= (select A (array-ext A B)) (select B (array-ext A B))) (= A B))
+     * Two arrays are equal if and only if they are equal on the index returned by this function.
+     */
+    function Ext<DomainSort extends NonEmptySortArray<Name>, RangeSort extends Sort<Name>>(
+      a: SMTArray<Name, DomainSort, RangeSort>,
+      b: SMTArray<Name, DomainSort, RangeSort>,
+    ): SortToExprMap<DomainSort[0], Name> {
+      return _toExpr(check(Z3.mk_array_ext(contextPtr, a.ast, b.ast))) as SortToExprMap<DomainSort[0], Name>;
+    }
+
     function SetUnion<ElemSort extends AnySort<Name>>(...args: SMTSet<Name, ElemSort>[]): SMTSet<Name, ElemSort> {
       return new SetImpl<ElemSort>(
         check(
@@ -2644,7 +2657,7 @@ export function createApi(Z3: Z3Core): Z3HighLevel {
         return new BoolImpl(check(Z3.mk_bvsub_no_overflow(contextPtr, this.ast, this.sort.cast(other).ast)));
       }
 
-      subNoUndeflow(other: CoercibleToBitVec<Bits, Name>, isSigned: boolean): Bool<Name> {
+      subNoUnderflow(other: CoercibleToBitVec<Bits, Name>, isSigned: boolean): Bool<Name> {
         return new BoolImpl(check(Z3.mk_bvsub_no_underflow(contextPtr, this.ast, this.sort.cast(other).ast, isSigned)));
       }
 
@@ -2656,7 +2669,7 @@ export function createApi(Z3: Z3Core): Z3HighLevel {
         return new BoolImpl(check(Z3.mk_bvmul_no_overflow(contextPtr, this.ast, this.sort.cast(other).ast, isSigned)));
       }
 
-      mulNoUndeflow(other: CoercibleToBitVec<Bits, Name>): Bool<Name> {
+      mulNoUnderflow(other: CoercibleToBitVec<Bits, Name>): Bool<Name> {
         return new BoolImpl(check(Z3.mk_bvmul_no_underflow(contextPtr, this.ast, this.sort.cast(other).ast)));
       }
 
@@ -2742,6 +2755,15 @@ export function createApi(Z3: Z3Core): Z3HighLevel {
       ): SMTArray<Name, DomainSort, RangeSort> {
         return Store(this, ...indicesAndValue);
       }
+
+      /**
+       * Access the array default value.
+       * Produces the default range value, for arrays that can be represented as
+       * finite maps with a default range value.
+       */
+      default(): SortToExprMap<RangeSort, Name> {
+        return _toExpr(check(Z3.mk_array_default(contextPtr, this.ast))) as SortToExprMap<RangeSort, Name>;
+      }
     }
 
     class SetImpl<ElemSort extends Sort<Name>>
@@ -3084,6 +3106,15 @@ export function createApi(Z3: Z3Core): Z3HighLevel {
       ): SMTArray<Name, DomainSort, RangeSort> {
         return Store(this, ...indicesAndValue);
       }
+
+      /**
+       * Access the array default value.
+       * Produces the default range value, for arrays that can be represented as
+       * finite maps with a default range value.
+       */
+      default(): SortToExprMap<RangeSort, Name> {
+        return _toExpr(check(Z3.mk_array_default(contextPtr, this.ast))) as SortToExprMap<RangeSort, Name>;
+      }
     }
 
     class AstVectorImpl<Item extends AnyAst<Name>> {
@@ -3396,6 +3427,7 @@ export function createApi(Z3: Z3Core): Z3HighLevel {
       Mod,
       Select,
       Store,
+      Ext,
       Extract,
 
       substitute,

src/api/js/src/high-level/types.ts

@@ -623,6 +623,12 @@ export interface Context<Name extends string = 'main'> {
     ]
   ): SMTArray<Name, DomainSort, RangeSort>;
 
+  /** @category Operations */
+  Ext<DomainSort extends NonEmptySortArray<Name>, RangeSort extends Sort<Name> = Sort<Name>>(
+    a: SMTArray<Name, DomainSort, RangeSort>,
+    b: SMTArray<Name, DomainSort, RangeSort>,
+  ): SortToExprMap<DomainSort[0], Name>;
+
   /** @category Operations */
   Extract<Bits extends number>(hi: number, lo: number, val: BitVec<Bits, Name>): BitVec<number, Name>;
 
@@ -1788,7 +1794,7 @@ export interface BitVec<Bits extends number = number, Name extends string = 'mai
   subNoOverflow(other: CoercibleToBitVec<Bits, Name>): Bool<Name>;
 
   /** @category Boolean */
-  subNoUndeflow(other: CoercibleToBitVec<Bits, Name>, isSigned: boolean): Bool<Name>;
+  subNoUnderflow(other: CoercibleToBitVec<Bits, Name>, isSigned: boolean): Bool<Name>;
 
   /** @category Boolean */
   sdivNoOverflow(other: CoercibleToBitVec<Bits, Name>): Bool<Name>;
@@ -1797,7 +1803,7 @@ export interface BitVec<Bits extends number = number, Name extends string = 'mai
   mulNoOverflow(other: CoercibleToBitVec<Bits, Name>, isSigned: boolean): Bool<Name>;
 
   /** @category Boolean */
-  mulNoUndeflow(other: CoercibleToBitVec<Bits, Name>): Bool<Name>;
+  mulNoUnderflow(other: CoercibleToBitVec<Bits, Name>): Bool<Name>;
 
   /** @category Boolean */
   negNoOverflow(): Bool<Name>;
@@ -1928,6 +1934,13 @@ export interface SMTArray<
       CoercibleToMap<SortToExprMap<RangeSort, Name>, Name>,
     ]
   ): SMTArray<Name, DomainSort, RangeSort>;
+
+  /**
+   * Access the array default value.
+   * Produces the default range value, for arrays that can be represented as
+   * finite maps with a default range value.
+   */
+  default(): SortToExprMap<RangeSort, Name>;
 }
 
 /**