Support REL range bounds as expressions

scripts/antlr4/Cypher.g4

@@ -684,7 +684,7 @@ kU_RecursiveType
 
 oC_RangeLiteral
     :  oC_LowerBound? SP? DOTDOT SP? oC_UpperBound?
-        | oC_IntegerLiteral ;
+        | oC_Expression ;
 
 kU_RecursiveComprehension
     : '(' SP? oC_Variable SP? ',' SP? oC_Variable ( SP? '|' SP? oC_Where SP? )? ( SP? '|' SP? kU_RecursiveProjectionItems SP? ',' SP? kU_RecursiveProjectionItems SP? )? ')' ;
@@ -693,10 +693,10 @@ kU_RecursiveProjectionItems
     : '{' SP? oC_ProjectionItems? SP? '}' ;
 
 oC_LowerBound
-    : DecimalInteger ;
+    : oC_Expression ;
 
 oC_UpperBound
-    : DecimalInteger ;
+    : oC_Expression ;
 
 oC_LabelName
     : oC_SchemaName ;

scripts/antlr4/hash.md5

@@ -1 +1 @@
-8334a684be17e562250acf07ae2bbca0
+c39017591a40317e1e5aabb586c04e45

src/antlr4/Cypher.g4

@@ -437,7 +437,7 @@ kU_RecursiveType
 
 oC_RangeLiteral
     :  oC_LowerBound? SP? DOTDOT SP? oC_UpperBound?
-        | oC_IntegerLiteral ;
+        | oC_Expression ;
 
 kU_RecursiveComprehension
     : '(' SP? oC_Variable SP? ',' SP? oC_Variable ( SP? '|' SP? oC_Where SP? )? ( SP? '|' SP? kU_RecursiveProjectionItems SP? ',' SP? kU_RecursiveProjectionItems SP? )? ')' ;
@@ -446,10 +446,10 @@ kU_RecursiveProjectionItems
     : '{' SP? oC_ProjectionItems? SP? '}' ;
 
 oC_LowerBound
-    : DecimalInteger ;
+    : oC_Expression ;
 
 oC_UpperBound
-    : DecimalInteger ;
+    : oC_Expression ;
 
 oC_LabelName
     : oC_SchemaName ;

src/binder/bind/bind_graph_pattern.cpp

@@ -10,7 +10,6 @@
 #include "common/exception/binder.h"
 #include "common/string_format.h"
 #include "common/utils.h"
-#include "function/cast/functions/cast_from_string_functions.h"
 #include "function/gds/rec_joins.h"
 #include "function/rewrite_function.h"
 #include "function/schema/vector_node_rel_functions.h"
@@ -526,15 +525,21 @@ expression_vector Binder::bindRecursivePatternRelProjectionList(const RecursiveR
 std::pair<uint64_t, uint64_t> Binder::bindVariableLengthRelBound(const RelPattern& relPattern) {
     auto recursiveInfo = relPattern.getRecursiveInfo();
     uint32_t lowerBound = 0;
-    function::CastString::operation(
-        ku_string_t{recursiveInfo->lowerBound.c_str(), recursiveInfo->lowerBound.length()},
-        lowerBound);
+    auto boundLowerExpression = expressionBinder.bindExpression(*recursiveInfo->lowerBound);
+    if (boundLowerExpression->expressionType != ExpressionType::LITERAL &&
+        boundLowerExpression->expressionType != ExpressionType::PARAMETER) {
+        throw BinderException("Rel range lower bound must be a parameter/literal expression.");
+    }
+    lowerBound = ExpressionUtil::evaluateAsVariableLengthRelBound(*boundLowerExpression);
     auto maxDepth = clientContext->getClientConfig()->varLengthMaxDepth;
     auto upperBound = maxDepth;
-    if (!recursiveInfo->upperBound.empty()) {
-        function::CastString::operation(
-            ku_string_t{recursiveInfo->upperBound.c_str(), recursiveInfo->upperBound.length()},
-            upperBound);
+    if (recursiveInfo->upperBound.get()) {
+        auto boundUpperExpression = expressionBinder.bindExpression(*recursiveInfo->upperBound);
+        if (boundUpperExpression->expressionType != ExpressionType::LITERAL &&
+            boundUpperExpression->expressionType != ExpressionType::PARAMETER) {
+            throw BinderException("Rel range upper bound must be a parameter/literal expression.");
+        }
+        upperBound = ExpressionUtil::evaluateAsVariableLengthRelBound(*boundUpperExpression);
     }
     if (lowerBound > upperBound) {
         throw BinderException(stringFormat("Lower bound of rel {} is greater than upperBound.",

src/binder/expression/expression_util.cpp

@@ -471,6 +471,22 @@ uint64_t ExpressionUtil::evaluateAsSkipLimit(const Expression& expr) {
     return number;
 }
 
+uint64_t ExpressionUtil::evaluateAsVariableLengthRelBound(const Expression& expr) {
+    auto value = evaluateAsLiteralValue(expr);
+    auto errorMsg = "Rel range upper/lower bound must be a non-negative integer.";
+    uint64_t number = INVALID_RELBOUND;
+    TypeUtils::visit(
+        value.getDataType(),
+        [&]<IntegerTypes T>(T) {
+            if (value.getValue<T>() < 0) {
+                throw BinderException{errorMsg};
+            }
+            number = (uint64_t)value.getValue<T>();
+        },
+        [&](auto) { throw BinderException{errorMsg}; });
+    return number;
+}
+
 template<typename T>
 T ExpressionUtil::getExpressionVal(const Expression& expr, const Value& value,
     const LogicalType& targetType, validate_param_func<T> validateParamFunc) {

src/include/binder/expression/expression_util.h

@@ -64,6 +64,7 @@ struct KUZU_API ExpressionUtil {
     static bool canEvaluateAsLiteral(const Expression& expr);
     static common::Value evaluateAsLiteralValue(const Expression& expr);
     static uint64_t evaluateAsSkipLimit(const Expression& expr);
+    static uint64_t evaluateAsVariableLengthRelBound(const Expression& expr);
 
     template<typename T>
     using validate_param_func = void (*)(T);

src/include/common/types/types.h

@@ -85,6 +85,7 @@ using relID_t = internalID_t;
 
 using cardinality_t = uint64_t;
 constexpr offset_t INVALID_LIMIT = UINT64_MAX;
+constexpr offset_t INVALID_RELBOUND = UINT32_MAX;
 using offset_vec_t = std::vector<offset_t>;
 // System representation for internalID.
 struct KUZU_API internalID_t {

src/include/parser/query/graph_pattern/rel_pattern.h

@@ -10,8 +10,8 @@ namespace parser {
 enum class ArrowDirection : uint8_t { LEFT = 0, RIGHT = 1, BOTH = 2 };
 
 struct RecursiveRelPatternInfo {
-    std::string lowerBound;
-    std::string upperBound;
+    std::unique_ptr<ParsedExpression> lowerBound = nullptr;
+    std::unique_ptr<ParsedExpression> upperBound = nullptr;
     std::string weightPropertyName;
     std::string relName;
     std::string nodeName;

src/parser/transform/transform_graph_pattern.cpp

@@ -1,4 +1,5 @@
 #include "common/assert.h"
+#include "parser/expression/parsed_literal_expression.h"
 #include "parser/query/graph_pattern/pattern_element.h"
 #include "parser/transformer.h"
 
@@ -126,23 +127,24 @@ RelPattern Transformer::transformRelationshipPattern(
             relType = QueryRelType::VARIABLE_LENGTH_WALK;
         }
         // Parse lower, upper bound
-        auto lowerBound = std::string("1");
-        auto upperBound = std::string("");
+        std::unique_ptr<ParsedExpression> lowerBound =
+            std::make_unique<ParsedLiteralExpression>(Value(1), "1");
+        std::unique_ptr<ParsedExpression> upperBound = nullptr;
         auto range = recursiveDetail->oC_RangeLiteral();
         if (range) {
-            if (range->oC_IntegerLiteral()) {
-                lowerBound = range->oC_IntegerLiteral()->getText();
-                upperBound = lowerBound;
+            if (range->oC_Expression()) {
+                lowerBound = transformExpression(*range->oC_Expression());
+                upperBound = lowerBound->copy();
             }
             if (range->oC_LowerBound()) {
-                lowerBound = range->oC_LowerBound()->getText();
+                lowerBound = transformExpression(*range->oC_LowerBound()->oC_Expression());
             }
             if (range->oC_UpperBound()) {
-                upperBound = range->oC_UpperBound()->getText();
+                upperBound = transformExpression(*range->oC_UpperBound()->oC_Expression());
             }
         }
-        recursiveInfo.lowerBound = lowerBound;
-        recursiveInfo.upperBound = upperBound;
+        recursiveInfo.lowerBound = std::move(lowerBound);
+        recursiveInfo.upperBound = std::move(upperBound);
         // Parse recursive comprehension
         auto comprehension = recursiveDetail->kU_RecursiveComprehension();
         if (comprehension) {

test/test_files/tck/match/match4.test

@@ -215,6 +215,5 @@ Parser exception: Invalid input <MATCH (a:A)            MATCH (a)-[:LIKES..>: ex
            MATCH (a)-[:LIKES*-2]->(c)
            RETURN c.name;
 ---- error
-Parser exception: Invalid input <MATCH (a:A)           MATCH (a)-[:LIKES*->: expected rule oC_SingleQuery (line: 1, offset: 40)
-"MATCH (a:A)           MATCH (a)-[:LIKES*-2]->(c)            RETURN c.name;"
-                                         ^
+Binder exception: Rel range upper/lower bound must be a non-negative integer.
+