implement IsNumeric; add support for hex/oct integer strings

git-svn-id: https://svn.code.sf.net/p/jackcess/code/jackcess/trunk@1199 f203690c-595d-4dc9-a70b-905162fa7fd2

3 files changed, 57 insertions, 6 deletions

diff --git a/src/main/java/com/healthmarketscience/jackcess/expr/package-info.java b/src/main/java/com/healthmarketscience/jackcess/expr/package-info.java
index 6531eea..416c96e 100644
--- a/src/main/java/com/healthmarketscience/jackcess/expr/package-info.java
+++ b/src/main/java/com/healthmarketscience/jackcess/expr/package-info.java
@@ -178,7 +178,7 @@ limitations under the License.
  * <tr class="TableRowColor"><td>IsError</td><td></td></tr>
  * <tr class="TableRowColor"><td>IsMissing</td><td></td></tr>
  * <tr class="TableRowColor"><td>IsNull</td><td>Y</td></tr>
- * <tr class="TableRowColor"><td>IsNumeric</td><td></td></tr>
+ * <tr class="TableRowColor"><td>IsNumeric</td><td>Y</td></tr>
  * <tr class="TableRowColor"><td>IsObject</td><td></td></tr>
  * <tr class="TableRowColor"><td>TypeName</td><td>Y</td></tr>
  * <tr class="TableRowColor"><td>VarType</td><td>Y</td></tr>
@@ -216,7 +216,7 @@ limitations under the License.
  *
  * <table border="1" width="25%" cellpadding="3" cellspacing="0">
  * <tr class="TableHeadingColor" align="left"><th>Function</th><th>Supported</th></tr>
- * <tr class="TableRowColor"><td>Format</td><td></td></tr>
+ * <tr class="TableRowColor"><td>Format[$]</td><td></td></tr>
  * <tr class="TableRowColor"><td>InStr</td><td>Y</td></tr>
  * <tr class="TableRowColor"><td>InStrRev</td><td>Y</td></tr>
  * <tr class="TableRowColor"><td>LCase[$]</td><td>Y</td></tr>
diff --git a/src/main/java/com/healthmarketscience/jackcess/impl/expr/DefaultFunctions.java b/src/main/java/com/healthmarketscience/jackcess/impl/expr/DefaultFunctions.java
index e927f9a..20de8ca 100644
--- a/src/main/java/com/healthmarketscience/jackcess/impl/expr/DefaultFunctions.java
+++ b/src/main/java/com/healthmarketscience/jackcess/impl/expr/DefaultFunctions.java
@@ -246,6 +246,26 @@ public class DefaultFunctions
     }
   });
 
+  public static final Function ISNUMERIC = registerFunc(new Func1("IsNumeric") {
+    @Override
+    protected Value eval1(EvalContext ctx, Value param1) {
+      if(param1.getType().isNumeric()) {
+        return ValueSupport.TRUE_VAL;
+      }
+
+      if(param1.getType() == Value.Type.STRING) {
+        try {
+          param1.getAsBigDecimal();
+          return ValueSupport.TRUE_VAL;
+        } catch(NumberFormatException ignored) {
+          // fall through to FALSE_VAL
+        }
+      }
+
+      return ValueSupport.FALSE_VAL;
+    }
+  });
+
   public static final Function VARTYPE = registerFunc(new Func1("VarType") {
     @Override
     protected Value eval1(EvalContext ctx, Value param1) {
diff --git a/src/main/java/com/healthmarketscience/jackcess/impl/expr/StringValue.java b/src/main/java/com/healthmarketscience/jackcess/impl/expr/StringValue.java
index d3e2cac..51b9c6a 100644
--- a/src/main/java/com/healthmarketscience/jackcess/impl/expr/StringValue.java
+++ b/src/main/java/com/healthmarketscience/jackcess/impl/expr/StringValue.java
@@ -17,6 +17,8 @@ limitations under the License.
 package com.healthmarketscience.jackcess.impl.expr;
 
 import java.math.BigDecimal;
+import java.math.BigInteger;
+import java.util.regex.Pattern;
 
 /**
  *
@@ -26,6 +28,12 @@ public class StringValue extends BaseValue
 {
   private static final Object NOT_A_NUMBER = new Object();
 
+  private static final char NUMBER_BASE_PREFIX = '&';
+  private static final Pattern OCTAL_PAT =
+    Pattern.compile(NUMBER_BASE_PREFIX + "[oO][0-7]+");
+  private static final Pattern HEX_PAT =
+    Pattern.compile(NUMBER_BASE_PREFIX + "[hH]\\p{XDigit}+");
+
   private final String _val;
   private Object _num;
 
@@ -75,13 +83,36 @@ public class StringValue extends BaseValue
     if(_num == null) {
       // see if it is parseable as a number
       try {
-        _num = ValueSupport.normalize(new BigDecimal(_val));
-        return (BigDecimal)_num;
+        // ignore extraneous whitespace whitespace and handle "&[hH]" or
+        // "&[oO]" prefix (only supports integers)
+        String tmpVal = _val.trim();
+        if(tmpVal.length() > 0) {
+
+          if(tmpVal.charAt(0) != NUMBER_BASE_PREFIX) {
+            // parse using standard numeric support
+            _num = ValueSupport.normalize(new BigDecimal(tmpVal));
+            return (BigDecimal)_num;
+          }
+
+          // parse as hex/octal symbolic value
+          if(HEX_PAT.matcher(tmpVal).matches()) {
+            return parseIntegerString(tmpVal, 16);
+          } else if(OCTAL_PAT.matcher(tmpVal).matches()) {
+            return parseIntegerString(tmpVal, 8);
+          }
+
+          // fall through to NaN
+        }
       } catch(NumberFormatException nfe) {
-        _num = NOT_A_NUMBER;
-        // fall through to throw...
+        // fall through to NaN...
       }
+      _num = NOT_A_NUMBER;
     }
     throw new NumberFormatException("Invalid number '" + _val + "'");
   }
+
+  private BigDecimal parseIntegerString(String tmpVal, int radix) {
+    _num = new BigDecimal(new BigInteger(tmpVal.substring(2), radix));
+    return (BigDecimal)_num;
+  }
 }