5.0.0 Release

README.md

@@ -125,16 +125,22 @@ The following properties are available in expressions:
 
  * **All first-class properties of the event** - no special syntax: `SourceContext` and `Cart` are used in the formatting examples above
  * `@t` - the event's timestamp, as a `DateTimeOffset`
- * `@m` - the rendered message
+ * `@m` - the rendered message (Note: do not add format specifiers like `:lj` or you'll lose theme color rendering. These format specifiers are not supported as they've become the default and only option - [see the discussion here](https://github.com/serilog/serilog-expressions/issues/56#issuecomment-1146472988)
  * `@mt` - the raw message template
  * `@l` - the event's level, as a `LogEventLevel`
  * `@x` - the exception associated with the event, if any, as an `Exception`
  * `@p` - a dictionary containing all first-class properties; this supports properties with non-identifier names, for example `@p['snake-case-name']`
  * `@i` - event id; a 32-bit numeric hash of the event's message template
  * `@r` - renderings; if any tokens in the message template include .NET-specific formatting, an array of rendered values for each such token
+ * `@tr` - trace id; The id of the trace that was active when the event was created, if any
+ * `@sp` - span id; The id of the span that was active when the event was created, if any
 
 The built-in properties mirror those available in the CLEF format.
 
+The exception property `@x` is treated as a scalar and will appear as a string when formatted into text. The properties of
+the underlying `Exception` object can be accessed using `Inspect()`, for example `Inspect(@x).Message`, and the type of the
+exception retrieved using `TypeOf(@x)`.
+
 ### Literals
 
 | Data type | Description | Examples |
@@ -181,29 +187,30 @@ calling a function will be undefined if:
  * any argument is undefined, or
  * any argument is of an incompatible type.
 
-| Function | Description |
-| :--- | :--- |
-| `Coalesce(p0, p1, [..pN])` | Returns the first defined, non-null argument. |
-| `Concat(s0, s1, [..sN])` | Concatenate two or more strings. |
-| `Contains(s, t)` | Tests whether the string `s` contains the substring `t`. |
-| `ElementAt(x, i)` | Retrieves a property of `x` by name `i`, or array element of `x` by numeric index `i`. |
-| `EndsWith(s, t)` | Tests whether the string `s` ends with substring `t`. |
-| `IndexOf(s, t)` | Returns the first index of substring `t` in string `s`, or -1 if the substring does not appear. |
-| `IndexOfMatch(s, p)` | Returns the index of the first match of regular expression `p` in string `s`, or -1 if the regular expression does not match. |
-| `IsMatch(s, p)` | Tests whether the regular expression `p` matches within the string `s`. |
-| `IsDefined(x)` | Returns `true` if the expression `x` has a value, including `null`, or `false` if `x` is undefined. |
-| `LastIndexOf(s, t)` | Returns the last index of substring `t` in string `s`, or -1 if the substring does not appear. |
-| `Length(x)` | Returns the length of a string or array. |
-| `Now()` | Returns `DateTimeOffset.Now`. |
-| `Rest([deep])` | In an `ExpressionTemplate`, returns an object containing the first-class event properties not otherwise referenced in the template. If `deep` is `true`, also excludes properties referenced in the event's message template. |
-| `Round(n, m)` | Round the number `n` to `m` decimal places. |
-| `StartsWith(s, t)` | Tests whether the string `s` starts with substring `t`. |
-| `Substring(s, start, [length])` | Return the substring of string `s` from `start` to the end of the string, or of `length` characters, if this argument is supplied. |
-| `TagOf(o)` | Returns the `TypeTag` field of a captured object (i.e. where `TypeOf(x)` is `'object'`). |
-| `ToString(x, [format])` | Convert `x` to a string, applying the format string `format` if `x` is `IFormattable`. |
-| `TypeOf(x)` | Returns a string describing the type of expression `x`: a .NET type name if `x` is scalar and non-null, or, `'array'`, `'object'`, `'dictionary'`, `'null'`, or `'undefined'`. |
-| `Undefined()` | Explicitly mark an undefined value. |
-| `UtcDateTime(x)` | Convert a `DateTime` or `DateTimeOffset` into a UTC `DateTime`. |
+| Function                        | Description                                                                                                                                                                                                                   |
+|:--------------------------------|:------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| `Coalesce(p0, p1, [..pN])`      | Returns the first defined, non-null argument.                                                                                                                                                                                 |
+| `Concat(s0, s1, [..sN])`        | Concatenate two or more strings.                                                                                                                                                                                              |
+| `Contains(s, t)`                | Tests whether the string `s` contains the substring `t`.                                                                                                                                                                      |
+| `ElementAt(x, i)`               | Retrieves a property of `x` by name `i`, or array element of `x` by numeric index `i`.                                                                                                                                        |
+| `EndsWith(s, t)`                | Tests whether the string `s` ends with substring `t`.                                                                                                                                                                         |
+| `IndexOf(s, t)`                 | Returns the first index of substring `t` in string `s`, or -1 if the substring does not appear.                                                                                                                               |
+| `IndexOfMatch(s, p)`            | Returns the index of the first match of regular expression `p` in string `s`, or -1 if the regular expression does not match.                                                                                                 |
+| `Inspect(o, [deep])`            | Read properties from an object captured as the scalar value `o`.                                                                                                                                                              |
+| `IsMatch(s, p)`                 | Tests whether the regular expression `p` matches within the string `s`.                                                                                                                                                       |
+| `IsDefined(x)`                  | Returns `true` if the expression `x` has a value, including `null`, or `false` if `x` is undefined.                                                                                                                           |
+| `LastIndexOf(s, t)`             | Returns the last index of substring `t` in string `s`, or -1 if the substring does not appear.                                                                                                                                |
+| `Length(x)`                     | Returns the length of a string or array.                                                                                                                                                                                      |
+| `Now()`                         | Returns `DateTimeOffset.Now`.                                                                                                                                                                                                 |
+| `Rest([deep])`                  | In an `ExpressionTemplate`, returns an object containing the first-class event properties not otherwise referenced in the template. If `deep` is `true`, also excludes properties referenced in the event's message template. |
+| `Round(n, m)`                   | Round the number `n` to `m` decimal places.                                                                                                                                                                                   |
+| `StartsWith(s, t)`              | Tests whether the string `s` starts with substring `t`.                                                                                                                                                                       |
+| `Substring(s, start, [length])` | Return the substring of string `s` from `start` to the end of the string, or of `length` characters, if this argument is supplied.                                                                                            |
+| `TagOf(o)`                      | Returns the `TypeTag` field of a captured object (i.e. where `TypeOf(x)` is `'object'`).                                                                                                                                      |
+| `ToString(x, [format])`         | Convert `x` to a string, applying the format string `format` if `x` is `IFormattable`.                                                                                                                                        |
+| `TypeOf(x)`                     | Returns a string describing the type of expression `x`: a .NET type name if `x` is scalar and non-null, or, `'array'`, `'object'`, `'dictionary'`, `'null'`, or `'undefined'`.                                                |
+| `Undefined()`                   | Explicitly mark an undefined value.                                                                                                                                                                                           |
+| `UtcDateTime(x)`                | Convert a `DateTime` or `DateTimeOffset` into a UTC `DateTime`.                                                                                                                                                               |
 
 Functions that compare text accept an optional postfix `ci` modifier to select case-insensitive comparisons:
 

appveyor.yml

@@ -8,7 +8,7 @@ artifacts:
 deploy:
 - provider: NuGet
   api_key:
-    secure: AcMGMnsJdQe1+SQwf+9VpRqcKNw93zr96OlxAEmPob52vqxDNH844SmdYidGX0cL
+    secure: ZCEcKeB0btSRWVPgGPqQKphQeTcljBBsA4GKGW0Gmjw+UfXvS0LCcWzYdPXUWo5N
   skip_symbols: true
   on:
     branch: /^(main|dev)$/

serilog-expressions.sln.DotSettings

@@ -1,4 +1,5 @@
 <wpf:ResourceDictionary xml:space="preserve" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:s="clr-namespace:System;assembly=mscorlib" xmlns:ss="urn:shemas-jetbrains-com:settings-storage-xaml" xmlns:wpf="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
+	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/Abbreviations/=CI/@EntryIndexedValue">CI</s:String>
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=Acerola/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=Comparand/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=delim/@EntryIndexedValue">True</s:Boolean>

src/Serilog.Expressions/Expressions/Ast/AccessorExpression.cs

@@ -14,6 +14,14 @@
 
 namespace Serilog.Expressions.Ast;
 
+/// <summary>
+/// An accessor retrieves a property from a (structured) object. For example, in the expression
+/// <code>Headers.ContentType</code> the <code>.</code> operator forms an accessor expression that
+/// retrieves the <code>ContentType</code> property from the <code>Headers</code> object.
+/// </summary>
+/// <remarks>Note that the AST type can represent accessors that cannot be validly written using
+/// <code>.</code> notation. In these cases, if the accessor is formatted back out as an expression,
+/// <see cref="IndexerExpression"/> notation will be used.</remarks>
 class AccessorExpression : Expression
 {
     public AccessorExpression(Expression receiver, string memberName)

src/Serilog.Expressions/Expressions/Ast/AmbientNameExpression.cs

@@ -14,6 +14,11 @@
 
 namespace Serilog.Expressions.Ast;
 
+/// <summary>
+/// An ambient name is generally a property name or built-in that appears standalone in an expression. For example,
+/// in <code>Headers.ContentType</code>, <code>Headers</code> is an ambient name that produces an
+/// <see cref="AmbientNameExpression"/>. Built-ins like <code>@Level</code> are also parsed as ambient names.
+/// </summary>
 class AmbientNameExpression : Expression
 {
     readonly bool _requiresEscape;

src/Serilog.Expressions/Expressions/Ast/ArrayExpression.cs

@@ -14,6 +14,13 @@
 
 namespace Serilog.Expressions.Ast;
 
+/// <summary>
+/// An array expression constructs an array from a list of elements. For example, <code>[1, 2, 3]</code> is an
+/// array expression. The items in an array expression can be literal values or expressions, like in the
+/// above example, or they can be spread expressions that describe zero or more elements to include in the
+/// list. Whether included via regular elements or spread expressions, undefined values are ignored and won't
+/// appear in the resulting array value.
+/// </summary>
 class ArrayExpression : Expression
 {
     public ArrayExpression(Element[] elements)

src/Serilog.Expressions/Expressions/Ast/CallExpression.cs

@@ -14,6 +14,10 @@
 
 namespace Serilog.Expressions.Ast;
 
+/// <summary>
+/// A <see cref="CallExpression"/> is a function call made up of the function name, parenthesised argument
+/// list, and optional postfix <code>ci</code> modifier. For example, <code>Substring(RequestPath, 0, 5)</code>.
+/// </summary>
 class CallExpression : Expression
 {
     public CallExpression(bool ignoreCase, string operatorName, params Expression[] operands)

src/Serilog.Expressions/Expressions/Ast/ConstantExpression.cs

@@ -17,6 +17,9 @@
 
 namespace Serilog.Expressions.Ast;
 
+/// <summary>
+/// A constant such as <code>'hello'</code>, <code>true</code>, <code>null</code>, or <code>123.45</code>.
+/// </summary>
 class ConstantExpression : Expression
 {
     public ConstantExpression(LogEventPropertyValue constant)
@@ -30,19 +33,14 @@ public override string ToString()
     {
         if (Constant is ScalarValue sv)
         {
-            switch (sv.Value)
+            return sv.Value switch
             {
-                case string s:
-                    return "'" + s.Replace("'", "''") + "'";
-                case true:
-                    return "true";
-                case false:
-                    return "false";
-                case IFormattable formattable:
-                    return formattable.ToString(null, CultureInfo.InvariantCulture);
-                default:
-                    return (sv.Value ?? "null").ToString() ?? "<ToString() returned null>";
-            }
+                string s => "'" + s.Replace("'", "''") + "'",
+                true => "true",
+                false => "false",
+                IFormattable formattable => formattable.ToString(null, CultureInfo.InvariantCulture),
+                _ => (sv.Value ?? "null").ToString() ?? "<ToString() returned null>"
+            };
         }
 
         return Constant.ToString();

src/Serilog.Expressions/Expressions/Ast/Element.cs

@@ -14,6 +14,7 @@
 
 namespace Serilog.Expressions.Ast;
 
-abstract class Element
-{
-}
+/// <summary>
+/// An element in an <see cref="ArrayExpression"/>.
+/// </summary>
+abstract class Element;

src/Serilog.Expressions/Expressions/Ast/Expression.cs

@@ -14,8 +14,15 @@
 
 namespace Serilog.Expressions.Ast;
 
+/// <summary>
+/// An AST node.
+/// </summary>
 abstract class Expression
 {
-    // Used only as an enabler for testing and debugging.
+    /// <summary>
+    /// The <see cref="ToString"/> representation of an <see cref="Expression"/> is <strong>not</strong>
+    /// guaranteed to be syntactically valid: this is provided for debugging purposes only.
+    /// </summary>
+    /// <returns>A textual representation of the expression.</returns>
     public abstract override string ToString();
 }

src/Serilog.Expressions/Expressions/Ast/IndexOfMatchExpression.cs

@@ -16,6 +16,10 @@
 
 namespace Serilog.Expressions.Ast;
 
+/// <summary>
+/// A non-syntax expression tree node used when compiling the <see cref="Operators.OpIndexOfMatch"/>,
+/// <see cref="Operators.OpIsMatch"/>, and SQL-style <code>like</code> expressions.
+/// </summary>
 class IndexOfMatchExpression : Expression
 {
     public Expression Corpus { get; }

src/Serilog.Expressions/Expressions/Ast/IndexerExpression.cs

@@ -14,6 +14,11 @@
 
 namespace Serilog.Expressions.Ast;
 
+/// <summary>
+/// An <see cref="IndexerExpression"/> retrieves a property from an object, by name, or an item from an array
+/// by zero-based numeric index. For example, <code>Headers['Content-Type']</code> and <code>Items[2]</code> are
+/// parsed as indexer expressions.
+/// </summary>
 class IndexerExpression : Expression
 {
     public Expression Receiver { get; }

src/Serilog.Expressions/Expressions/Ast/IndexerWildcard.cs

@@ -14,4 +14,7 @@
 
 namespace Serilog.Expressions.Ast;
 
+/// <summary>
+/// Describes the wildcard in a <see cref="IndexerWildcardExpression"/>.
+/// </summary>
 enum IndexerWildcard { Undefined, Any, All }

src/Serilog.Expressions/Expressions/Ast/IndexerWildcardExpression.cs

@@ -14,6 +14,11 @@
 
 namespace Serilog.Expressions.Ast;
 
+/// <summary>
+/// An indexer wildcard is a placeholder in a property path expression. For example,
+/// in <code>Headers[?] = 'test'</code>, the question-mark token is a wildcard that means "any property of
+/// the <code>Headers</code> object". The other wildcard indexer is the asterisk, meaning "all".
+/// </summary>
 class IndexerWildcardExpression : Expression
 {
     public IndexerWildcardExpression(IndexerWildcard wildcard)

src/Serilog.Expressions/Expressions/Ast/ItemElement.cs

@@ -14,6 +14,9 @@
 
 namespace Serilog.Expressions.Ast;
 
+/// <summary>
+/// A single item in an <see cref="ArrayExpression"/>.
+/// </summary>
 class ItemElement : Element
 {
     public Expression Value { get; }

src/Serilog.Expressions/Expressions/Ast/LambdaExpression.cs

@@ -14,6 +14,10 @@
 
 namespace Serilog.Expressions.Ast;
 
+/// <summary>
+/// A non-syntax expression tree node used in the compilation of <see cref="IndexerWildcardExpression"/>. Only
+/// very limited support for lambda expressions is currently present.
+/// </summary>
 class LambdaExpression : Expression
 {
     public LambdaExpression(ParameterExpression[] parameters, Expression body)

src/Serilog.Expressions/Expressions/Ast/LocalNameExpression.cs

@@ -14,6 +14,9 @@
 
 namespace Serilog.Expressions.Ast;
 
+/// <summary>
+/// Represents the iteration variable in template <code>#each</code> directives.
+/// </summary>
 class LocalNameExpression : Expression
 {
     public LocalNameExpression(string name)

src/Serilog.Expressions/Expressions/Ast/Member.cs

@@ -14,6 +14,7 @@
 
 namespace Serilog.Expressions.Ast;
 
-abstract class Member
-{
-}
+/// <summary>
+/// A member in an <see cref="ObjectExpression"/>.
+/// </summary>
+abstract class Member;

src/Serilog.Expressions/Expressions/Ast/ObjectExpression.cs

@@ -14,6 +14,11 @@
 
 namespace Serilog.Expressions.Ast;
 
+/// <summary>
+/// Constructs an object given a list of members. Members can be <code>name: value</code> pairs, or spread
+/// expressions that include members from another object. Where names conflict, the rightmost appearance of
+/// a name wins. Members that evaluate to an undefined value do not appear in the resulting object.
+/// </summary>
 class ObjectExpression : Expression
 {
     public ObjectExpression(Member[] members)

src/Serilog.Expressions/Expressions/Ast/ParameterExpression.cs

@@ -14,6 +14,9 @@
 
 namespace Serilog.Expressions.Ast;
 
+/// <summary>
+/// Non-syntax expression type used to represent parameters in <see cref="LambdaExpression"/> bodies.
+/// </summary>
 class ParameterExpression : Expression
 {
     public ParameterExpression(string parameterName)

src/Serilog.Expressions/Expressions/Ast/PropertyMember.cs

@@ -16,6 +16,11 @@
 
 namespace Serilog.Expressions.Ast;
 
+/// <summary>
+/// An <see cref="ObjectExpression"/> member comprising an optionally-quoted name and a value, for example
+/// the object <code>{Username: 'alice'}</code> includes a single <see cref="PropertyMember"/> with name
+/// <code>Username</code> and value <code>'alice'</code>.
+/// </summary>
 class PropertyMember : Member
 {
     public string Name { get; }