fix per recommendation

Signed-off-by: Asif Bashar <[email protected]>

Author: asifabashar

docs/user/ppl/functions/conversion.rst

@@ -84,50 +84,44 @@ TONUMBER
 
 Description
 >>>>>>>>>>>
+
 The following usage options are available, depending on the parameter types and the number of parameters.
 
 Usage: tonumber(string, [base]) converts the value in first argument to provided base type string in second argument. If second argument is not provided, then it converts to base 10 number representation.
+
 Return type: Number
 
 
 You can use this function with the eval commands and as part of eval expressions.
 Base values can be between 2 and 36.
 
-
-
-Basic examples:
 You can use this function to convert a string representation of a binary number to return the corresponding number in base 10.
 
-For example, the result of the following function is 5:
-eval result = tonumber("0101", 2)
-
+Following example converts a string in binary to the number representation::
 
-Example::
-Following example converts a string in binary to the number representation.
-    os> source=EMP | eval int_value = tonumber('010101',2) | fields int_value|head 1
+    os> source=EMP | eval int_value = tonumber('010101',2) | fields int_value | head 1
     fetched rows / total rows = 1/1
-    +--------------+
-    | int_value    |
-    |--------------+
-    | 21.0         |
-    +--------------+
+    +---------------+
+    |  int_value    |
+    |---------------+
+    |  21.0         |
+    +---------------+
+
 
+Following example converts a string in hex to the number representation::
 
-Following example converts a string in hex to the number representation.
-Example::
 
-    os> source=EMP | eval int_value = tonumber('FA34',16) | fields int_value|head 1
+    os> source=EMP | eval int_value = tonumber('FA34',16) | fields int_value | head 1
     fetched rows / total rows = 1/1
     +---------------+
     | int_value     |
     |---------------+
     | 64052.0       |
     +---------------+
 
-Following example converts a string in decimal  to the number representation.
-Example::
+Following example converts a string in decimal  to the number representation::
 
-     os> source=EMP | eval int_value = tonumber('4598') | fields int_value|head 1
+     os> source=EMP | eval int_value = tonumber('4598') | fields int_value | head 1
      fetched rows / total rows = 1/1
     +---------------+
     | int_value     |

ppl/src/main/antlr/OpenSearchPPLParser.g4

@@ -848,10 +848,9 @@ evalFunctionCall
    ;
 
 
-// cast, tostring function
+// cast function
 dataTypeFunctionCall
    : CAST LT_PRTHS logicalExpression AS convertedDataType RT_PRTHS
-   | TONUMBER LT_PRTHS functionArgs RT_PRTHS
    ;
 
 
@@ -1234,6 +1233,7 @@ textFunctionName
    | LOCATE
    | REPLACE
    | REVERSE
+   | TONUMBER
    ;
 
 positionFunctionName

ppl/src/main/java/org/opensearch/sql/ppl/parser/AstExpressionBuilder.java

@@ -431,39 +431,7 @@ public DataTypeFunctionCallContext createDataTypeFunctionCallContext(String cast
   /** Cast function. */
   @Override
   public UnresolvedExpression visitDataTypeFunctionCall(DataTypeFunctionCallContext ctx) {
-    if (ctx.functionArgs() != null) {
-
-      ParseTree rootNode = ctx.getChild(0);
-      String functionName = rootNode.getText();
-      final String mappedName =
-          FUNCTION_NAME_MAPPING.getOrDefault(functionName.toLowerCase(Locale.ROOT), functionName);
-      System.out.println(mappedName);
-      if (mappedName != null && mappedName.equals("tostring")) {
-        if (ctx.functionArgs().functionArg().size() == 1) {
-          List<OpenSearchPPLParser.FunctionArgContext> functionArgs =
-              ctx.functionArgs().functionArg();
-
-          String castExpresstion =
-              String.format("cast( %s as String)", functionArgs.getFirst().getText());
-          DataTypeFunctionCallContext toStringDataTypeConversionContext =
-              this.createDataTypeFunctionCallContext(castExpresstion);
-          return new Cast(
-              visit(toStringDataTypeConversionContext.logicalExpression()),
-              visit(toStringDataTypeConversionContext.convertedDataType()));
-          //
-        } else {
-          return buildFunction(mappedName, ctx.functionArgs().functionArg());
-        }
-      } else if (mappedName != null && mappedName.equals("tonumber")) {
-
-          return buildFunction(mappedName, ctx.functionArgs().functionArg());
-
-      }  else {
-        return new Cast(visit(ctx.logicalExpression()), visit(ctx.convertedDataType()));
-      }
-    } else {
       return new Cast(visit(ctx.logicalExpression()), visit(ctx.convertedDataType()));
-    }
   }
 
   @Override