Merge pull request #40 from nblumhardt/replace-function

Add support for `Replace()` with string arguments (no regex support)

Author: nblumhardt

src/Seq.Syntax/Expressions/Operators.cs

@@ -42,6 +42,7 @@ static class Operators
     public const string OpLastIndexOf = "LastIndexOf";
     public const string OpLength = "Length";
     public const string OpNow = "Now";
+    public const string OpReplace = "Replace";
     public const string OpRound = "Round";
     public const string OpStartsWith = "StartsWith";
     public const string OpSubstring = "Substring";

src/Seq.Syntax/Expressions/Runtime/RuntimeOperators.cs

@@ -464,6 +464,16 @@ public static LogEventPropertyValue _Internal_IsNotNull(LogEventPropertyValue? v
 
         return new ScalarValue(str.Substring((int)si, (int)len));
     }
+    
+    public static LogEventPropertyValue? Replace(StringComparison sc, LogEventPropertyValue? @string, LogEventPropertyValue? substring, LogEventPropertyValue? replacement)
+    {
+        if (!Coerce.String(@string, out var str) ||
+            !Coerce.String(substring, out var sub) ||
+            !Coerce.String(replacement, out var rep))
+            return null;
+
+        return new ScalarValue(str.Replace(sub, rep, sc));
+    }
 
     public static LogEventPropertyValue? Concat(LogEventPropertyValue? string0, LogEventPropertyValue? string1)
     {

test/Seq.Syntax.Tests/Cases/expression-evaluation-cases.asv

@@ -302,3 +302,10 @@ uriencode(' ')                       ⇶ '%20'
 
 tostring(@l, 'u3')                   ⇶ 'INF'
 tostring(@Elapsed)                   ⇶ '00:10:00'
+
+// Replace
+Replace('xYX', 'x', 'z')           ⇶ 'zYX'
+Replace('xYX', 'x', 'z') ci        ⇶ 'zYz'
+Replace('mess', 'ss', 'an')        ⇶ 'mean'
+Replace('mess', 's', 'an')         ⇶ 'meanan'
+Replace('xyz', 'x', '$0')          ⇶ '$0yz'