Implement SPACE() function for SQL3 (#2399)

FB-1861

(cherry picked from commit da74f0a312)

sql3/planner/expression.go

@@ -1512,6 +1512,8 @@ func (n *callPlanExpression) Evaluate(currentRow []interface{}) (interface{}, er
 		return n.EvaluateSuffix(currentRow)
 	case "PREFIX":
 		return n.EvaluatePrefix(currentRow)
+	case "SPACE":
+		return n.EvaluateSpace(currentRow)
 	default:
 		return nil, sql3.NewErrInternalf("unhandled function name '%s'", n.name)
 	}

sql3/planner/expressionanalyzercall.go

@@ -265,6 +265,8 @@ func (p *ExecutionPlanner) analyzeCallExpression(call *parser.Call, scope parser
 		return p.analyseFunctionPrefixSuffix(call, scope)
 	case "PREFIX":
 		return p.analyseFunctionPrefixSuffix(call, scope)
+	case "SPACE":
+		return p.analyseFunctionSpace(call, scope)
 	default:
 		return nil, sql3.NewErrCallUnknownFunction(call.Name.NamePos.Line, call.Name.NamePos.Column, call.Name.Name)
 	}

sql3/planner/inbuiltfunctionsstring.go

@@ -147,6 +147,21 @@ func (p *ExecutionPlanner) analyzeFunctionUpper(call *parser.Call, scope parser.
 	return call, nil
 }
 
+func (p *ExecutionPlanner) analyseFunctionSpace(call *parser.Call, scope parser.Statement) (parser.Expr, error) {
+	//one argument
+	if len(call.Args) != 1 {
+		return nil, sql3.NewErrCallParameterCountMismatch(call.Rparen.Line, call.Rparen.Column, call.Name.Name, 1, len(call.Args))
+	}
+
+	if !typeIsInteger(call.Args[0].DataType()) {
+		return nil, sql3.NewErrIntExpressionExpected(call.Args[0].Pos().Line, call.Args[0].Pos().Column)
+	}
+
+	call.ResultDataType = parser.NewDataTypeString()
+
+	return call, nil
+}
+
 // Convert string to Upper case
 func (n *callPlanExpression) EvaluateUpper(currentRow []interface{}) (interface{}, error) {
 	stringArgOne, err := evaluateStringArg(n.args[0], currentRow)
@@ -403,3 +418,18 @@ func (n *callPlanExpression) EvaluateSuffix(currentRow []interface{}) (interface
 
 	return stringArgOne[len(stringArgOne)-intArgTwo:], nil
 }
+
+func (n *callPlanExpression) EvaluateSpace(currentRow []interface{}) (interface{}, error) {
+	// Get the integer argument from the function call
+	intArg, err := evaluateIntArg(n.args[0], currentRow)
+	if err != nil {
+		return "", err
+	}
+
+	// Return a string containing a number of spaces equal to the integer value
+	spaces := ""
+	for i := 0; i < intArg; i++ {
+		spaces += " "
+	}
+	return spaces, nil
+}

sql3/test/defs/defs_string_functions.go

@@ -466,5 +466,31 @@ var stringScalarFunctionsTests = TableTest{
 			),
 			ExpErr: "string expression expected",
 		},
+		{
+			name: "SpaceZero",
+			SQLs: sqls(
+				"select space(0)",
+			),
+			ExpHdrs: hdrs(
+				hdr("", fldTypeString),
+			),
+			ExpRows: rows(
+				row(string("")),
+			),
+			Compare: CompareExactOrdered,
+		},
+		{
+			name: "SpaceFive",
+			SQLs: sqls(
+				"select space(5)",
+			),
+			ExpHdrs: hdrs(
+				hdr("", fldTypeString),
+			),
+			ExpRows: rows(
+				row(string("     ")),
+			),
+			Compare: CompareExactOrdered,
+		},
 	},
 }