Handle range inclusivity, escaping and short forms (#130)

Author: ejsmith

README.md

@@ -56,12 +56,52 @@ var wildcardRange = DateTimeRange.Parse("[2023-01-01 TO *]", DateTime.Now); // F
 
 #### Date Math Features
 
-Supports full Elasticsearch date math syntax following [official specifications](https://www.elastic.co/guide/en/elasticsearch/reference/current/common-options.html#date-math):
+Supports full [Elasticsearch date math syntax](https://www.elastic.co/guide/en/elasticsearch/reference/current/common-options.html#date-math):
 
 - **Anchors**: `now`, explicit dates with `||` separator
-- **Operations**: `+1d` (add), `-1h` (subtract), `/d` (round down)
+- **Operations**: `+1d` (add), `-1h` (subtract), `/d` (round)
 - **Units**: `y` (years), `M` (months), `w` (weeks), `d` (days), `h`/`H` (hours), `m` (minutes), `s` (seconds)
 - **Timezone Support**: Preserves explicit timezones (`Z`, `+05:00`, `-08:00`) or uses system timezone as fallback
+- **Escaped slashes**: `\/d` is treated identically to `/d` for contexts where `/` must be escaped
+
+##### Real-World Patterns
+
+```csharp
+// Common date range queries
+var thisMonth     = DateTimeRange.Parse("[now/M TO now/M]", now);    // Start of month through end of month
+var lastMonth     = DateTimeRange.Parse("[now-1M/M TO now/M}", now); // Start of last month through start of this month
+var yearToDate    = DateTimeRange.Parse("[now/y TO now]", now);      // Start of year through now
+var last7Days     = DateTimeRange.Parse("[now-7d/d TO now]", now);   // Start of 7 days ago through now
+var last15Minutes = DateTimeRange.Parse("[now-15m TO now]", now);    // 15 minutes ago through now
+var last24Hours   = DateTimeRange.Parse("[now-24h TO now]", now);    // 24 hours ago through now
+var tomorrow      = DateTimeRange.Parse("[now+1d/d TO now+1d/d]", now); // Start through end of tomorrow
+
+// Short-form comparison operators
+var recentItems   = DateTimeRange.Parse(">=now-1h", now);    // From 1 hour ago to max
+var futureOnly    = DateTimeRange.Parse(">now", now);         // After now to max
+var beforeToday   = DateTimeRange.Parse("<now/d", now);       // Min to start of today
+var throughToday  = DateTimeRange.Parse("<=now/d", now);      // Min to end of today
+```
+
+##### Rounding Behavior with Boundaries
+
+Rounding direction (`/d`, `/M`, etc.) is controlled by boundary inclusivity, following [Elasticsearch range query rounding rules](https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-range-query.html#date-math-rounding):
+
+| Boundary | Bracket | Operator | Rounding direction | `now/d` resolves to |
+| ---------- | --------- | ---------- | -------------------- | --------------------- |
+| Inclusive lower | `[` | `>=` | Floor (start of period) | `2025-02-16T00:00:00` |
+| Exclusive lower | `{` | `>` | Ceiling (end of period) | `2025-02-16T23:59:59.999` |
+| Inclusive upper | `]` | `<=` | Ceiling (end of period) | `2025-02-16T23:59:59.999` |
+| Exclusive upper | `}` | `<` | Floor (start of period) | `2025-02-16T00:00:00` |
+
+All four bracket combinations are supported: `[]`, `[}`, `{]`, `{}`.
+
+```csharp
+// [now/d TO now/d]  → start of today through end of today (full day, inclusive both ends)
+// [now/d TO now/d}  → start of today through start of today (exclusive upper)
+// {now/d TO now/d]  → end of today through end of today (exclusive lower)
+// {now/d TO now/d}  → collapsed to start of today (exclusive both ends inverts the range, which is then normalized)
+```
 
 Examples:
 

src/Exceptionless.DateTimeExtensions/DateMath.cs

@@ -29,11 +29,12 @@ public static class DateMath
     // https://www.elastic.co/docs/reference/elasticsearch/rest-apis/common-options
     internal static readonly Regex Parser = new(
         @"\G(?<anchor>now|(?<date>\d{4}-?\d{2}-?\d{2}(?:[T\s](?:\d{1,2}(?::?\d{2}(?::?\d{2})?)?(?:\.\d{1,3})?)?(?:[+-]\d{2}:?\d{2}|Z)?)?)\|\|)" +
-        @"(?<operations>(?:[+\-/]\d*[yMwdhHms])*)(?=\s|$|[\]\}])",
+        @"(?<operations>(?:(?:[+\-]|\\?/)\d*[yMwdhHms])*)(?=\s|$|[\]\}])",
         RegexOptions.Compiled);
 
     // Pre-compiled regex for operation parsing to avoid repeated compilation
-    private static readonly Regex _operationRegex = new(@"([+\-/])(\d*)([yMwdhHms])", RegexOptions.Compiled);
+    // Supports both / and \/ (escaped forward slash) for rounding operations
+    private static readonly Regex _operationRegex = new(@"([+\-]|\\?/)(\d*)([yMwdhHms])", RegexOptions.Compiled);
 
     // Pre-compiled regex for offset parsing to avoid repeated compilation
     private static readonly Regex _offsetRegex = new(@"(Z|[+-]\d{2}:\d{2})$", RegexOptions.Compiled);
@@ -461,12 +462,12 @@ public static DateTimeOffset ApplyOperations(DateTimeOffset baseTime, string ope
             throw new ArgumentException("Invalid operations");
         }
 
-        // Validate that rounding operations (/) are only at the end
+        // Validate that rounding operations (/ or \/) are only at the end
         // According to Elasticsearch spec, rounding must be the final operation
         bool foundRounding = false;
         for (int i = 0; i < matches.Count; i++)
         {
-            string operation = matches[i].Groups[1].Value;
+            string operation = matches[i].Groups[1].Value.TrimStart('\\');
             if (String.Equals(operation, "/"))
             {
                 if (foundRounding)
@@ -485,7 +486,8 @@ public static DateTimeOffset ApplyOperations(DateTimeOffset baseTime, string ope
 
         foreach (Match opMatch in matches)
         {
-            string operation = opMatch.Groups[1].Value;
+            // Normalize escaped forward slash (\/) to unescaped (/) for rounding operations
+            string operation = opMatch.Groups[1].Value.TrimStart('\\');
             string amountStr = opMatch.Groups[2].Value;
             string unit = opMatch.Groups[3].Value;
 

src/Exceptionless.DateTimeExtensions/FormatParsers/FormatParsers/ComparisonFormatParser.cs

@@ -0,0 +1,86 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text.RegularExpressions;
+using Exceptionless.DateTimeExtensions.FormatParsers.PartParsers;
+
+namespace Exceptionless.DateTimeExtensions.FormatParsers;
+
+/// <summary>
+/// Parses short-form comparison operators (>, >=, &lt;, &lt;=) as syntactic sugar for
+/// ranges with one open end. The operator determines boundary inclusivity, which
+/// controls rounding direction for date math expressions.
+///
+/// Operator mapping (per Elasticsearch range query semantics):
+///   >value  → exclusive lower bound → isUpperLimit = true  → rounds to end of period
+///   >=value → inclusive lower bound → isUpperLimit = false → rounds to start of period
+///   &lt;value  → exclusive upper bound → isUpperLimit = false → rounds to start of period
+///   &lt;=value → inclusive upper bound → isUpperLimit = true  → rounds to end of period
+///
+/// Examples:
+///   >now/d  → range from end of today to MaxValue
+///   >=now/d → range from start of today to MaxValue
+///   &lt;now/d  → range from MinValue to start of today
+///   &lt;=now/d → range from MinValue to end of today
+/// </summary>
+[Priority(24)]
+public class ComparisonFormatParser : IFormatParser
+{
+    private static readonly Regex _operatorRegex = new(@"^\s*(>=?|<=?)\s*", RegexOptions.Compiled);
+
+    public ComparisonFormatParser()
+    {
+        Parsers = new List<IPartParser>(DateTimeRange.PartParsers);
+    }
+
+    public List<IPartParser> Parsers { get; private set; }
+
+    public DateTimeRange Parse(string content, DateTimeOffset relativeBaseTime)
+    {
+        var opMatch = _operatorRegex.Match(content);
+        if (!opMatch.Success)
+            return null;
+
+        string op = opMatch.Groups[1].Value;
+        int index = opMatch.Length;
+
+        // Must have an expression after the operator
+        if (index >= content.Length || content.Substring(index).Trim().Length == 0)
+            return null;
+
+        // Determine inclusivity from operator
+        bool isLowerBound = op[0] == '>';
+        bool isInclusive = op.Length == 2; // >= or <=
+
+        // isUpperLimit follows the boundary inclusivity rule:
+        // For lower bounds: isUpperLimit = !inclusive (gt rounds up, gte rounds down)
+        // For upper bounds: isUpperLimit = inclusive (lte rounds up, lt rounds down)
+        bool isUpperLimit = isLowerBound ? !isInclusive : isInclusive;
+
+        DateTimeOffset? value = null;
+        foreach (var parser in Parsers.Where(p => p is not WildcardPartParser))
+        {
+            var match = parser.Regex.Match(content, index);
+            if (!match.Success)
+                continue;
+
+            value = parser.Parse(match, relativeBaseTime, isUpperLimit);
+            if (value == null)
+                continue;
+
+            index += match.Length;
+            break;
+        }
+
+        if (value == null)
+            return null;
+
+        // Verify entire input was consumed (only trailing whitespace allowed)
+        if (index < content.Length && content.Substring(index).Trim().Length > 0)
+            return null;
+
+        return isLowerBound
+            ? new DateTimeRange(value.Value, DateTimeOffset.MaxValue)
+            : new DateTimeRange(DateTimeOffset.MinValue, value.Value);
+    }
+}

src/Exceptionless.DateTimeExtensions/FormatParsers/FormatParsers/TwoPartFormatParser.cs

@@ -57,6 +57,7 @@ public DateTimeRange Parse(string content, DateTimeOffset relativeBaseTime)
         if (!IsValidBracketPair(openingBracket, closingBracket))
             return null;
 
+        // Determine isUpperLimit from bracket inclusivity (per Elasticsearch date math rounding spec):
         // Inclusive min ([): round down (start of period) — ">= start"
         // Exclusive min ({): round up (end of period) — "> end"
         bool minInclusive = openingBracket != '{';
@@ -124,7 +125,7 @@ public DateTimeRange Parse(string content, DateTimeOffset relativeBaseTime)
 
     /// <summary>
     /// Validates that opening and closing brackets form a valid pair.
-    /// Both Elasticsearch bracket types can be mixed: [ with ], [ with }, { with ], { with }.
+    /// All four Elasticsearch bracket combinations are valid: [/], [/}, {/], {/}.
     /// </summary>
     private static bool IsValidBracketPair(char? opening, char? closing)
     {

tests/Exceptionless.DateTimeExtensions.Tests/DateMathTests.cs

@@ -905,4 +905,40 @@ public void IsValidExpression_CaseSensitiveInputs_ValidatesCorrectly()
         Assert.False(DateMath.IsValidExpression("Now-7d"));
         Assert.False(DateMath.IsValidExpression("NOW-7d"));
     }
+
+    /// <summary>
+    /// Tests that escaped forward slash (\/) is handled identically to unescaped forward slash (/)
+    /// in date math rounding operations. This is important for contexts where / is escaped
+    /// (e.g., Lucene query syntax).
+    /// </summary>
+    [Theory]
+    [InlineData("now/d", @"now\/d", false)]
+    [InlineData("now/d", @"now\/d", true)]
+    [InlineData("now+1d/d", @"now+1d\/d", false)]
+    [InlineData("now+1d/d", @"now+1d\/d", true)]
+    [InlineData("now-1M/M", @"now-1M\/M", false)]
+    [InlineData("now-1M/M", @"now-1M\/M", true)]
+    [InlineData("now/h", @"now\/h", false)]
+    [InlineData("now/h", @"now\/h", true)]
+    public void Parse_EscapedAndUnescapedSlash_ProduceIdenticalResults(string unescaped, string escaped, bool isUpperLimit)
+    {
+        _logger.LogDebug("Testing escaped vs unescaped: '{Unescaped}' vs '{Escaped}', IsUpperLimit: {IsUpperLimit}",
+            unescaped, escaped, isUpperLimit);
+
+        var unescapedResult = DateMath.Parse(unescaped, _baseTime, isUpperLimit);
+        var escapedResult = DateMath.Parse(escaped, _baseTime, isUpperLimit);
+
+        _logger.LogDebug("Unescaped result: {Unescaped}, Escaped result: {Escaped}", unescapedResult, escapedResult);
+
+        Assert.Equal(unescapedResult, escapedResult);
+    }
+
+    [Theory]
+    [InlineData(@"now\/d")]
+    [InlineData(@"now+1h\/h")]
+    [InlineData(@"now-1d\/d")]
+    public void IsValidExpression_EscapedSlash_ReturnsTrue(string expression)
+    {
+        Assert.True(DateMath.IsValidExpression(expression));
+    }
 }

tests/Exceptionless.DateTimeExtensions.Tests/DateTimeRangeTests.cs

@@ -438,4 +438,102 @@ public void Parse_MixedBracketsWithDateMathOperations_ParsesCorrectly()
         Assert.Equal(baseTime.AddDays(-1).StartOfDay(), range.Start);
         Assert.Equal(baseTime.StartOfDay(), range.End);
     }
+
+    /// <summary>
+    /// Short-form operators are syntactic sugar for ranges with one open end.
+    /// The parser must interpret the operator's inclusive/exclusive semantics
+    /// correctly so that downstream rounding (driven by the isUpperLimit flag)
+    /// produces the expected boundaries.
+    ///
+    /// >value  → exclusive lower bound → treated as an upper-limit rounding case (isUpperLimit = true)
+    /// >=value → inclusive lower bound → treated as a lower-limit rounding case (isUpperLimit = false)
+    /// &lt;value  → exclusive upper bound → treated as a lower-limit rounding case (isUpperLimit = false)
+    /// &lt;=value → inclusive upper bound → treated as an upper-limit rounding case (isUpperLimit = true)
+    /// </summary>
+    [Fact]
+    public void Parse_GreaterThanWithRounding_RoundsToEndOfPeriod()
+    {
+        // >now/d → exclusive lower → isUpperLimit=true → rounds to end of day
+        // Range: (end_of_today, MaxValue)
+        var range = DateTimeRange.Parse(">now/d", _now);
+        Assert.NotEqual(DateTimeRange.Empty, range);
+        Assert.Equal(_now.EndOfDay(), range.Start);
+        Assert.Equal(DateTime.MaxValue, range.End);
+    }
+
+    [Fact]
+    public void Parse_GreaterThanOrEqualWithRounding_RoundsToStartOfPeriod()
+    {
+        // >=now/d → inclusive lower → isUpperLimit=false → rounds to start of day
+        // Range: [start_of_today, MaxValue)
+        var range = DateTimeRange.Parse(">=now/d", _now);
+        Assert.NotEqual(DateTimeRange.Empty, range);
+        Assert.Equal(_now.StartOfDay(), range.Start);
+        Assert.Equal(DateTime.MaxValue, range.End);
+    }
+
+    [Fact]
+    public void Parse_LessThanWithRounding_RoundsToStartOfPeriod()
+    {
+        // <now/d → exclusive upper → isUpperLimit=false → rounds to start of day
+        // Range: (MinValue, start_of_today)
+        var range = DateTimeRange.Parse("<now/d", _now);
+        Assert.NotEqual(DateTimeRange.Empty, range);
+        Assert.Equal(DateTime.MinValue, range.Start);
+        Assert.Equal(_now.StartOfDay(), range.End);
+    }
+
+    [Fact]
+    public void Parse_LessThanOrEqualWithRounding_RoundsToEndOfPeriod()
+    {
+        // <=now/d → inclusive upper → isUpperLimit=true → rounds to end of day
+        // Range: (MinValue, end_of_today]
+        var range = DateTimeRange.Parse("<=now/d", _now);
+        Assert.NotEqual(DateTimeRange.Empty, range);
+        Assert.Equal(DateTime.MinValue, range.Start);
+        Assert.Equal(_now.EndOfDay(), range.End);
+    }
+
+    [Theory]
+    [InlineData(">now-1h")]
+    [InlineData(">=now-1h")]
+    [InlineData("<now+1h")]
+    [InlineData("<=now+1h")]
+    public void Parse_ComparisonOperatorsWithoutRounding_ParseSuccessfully(string input)
+    {
+        var range = DateTimeRange.Parse(input, _now);
+        Assert.NotEqual(DateTimeRange.Empty, range);
+    }
+
+    [Fact]
+    public void Parse_GreaterThanWithMonthRounding_RoundsCorrectly()
+    {
+        // >now/M → exclusive lower → isUpperLimit=true → rounds to end of month
+        var range = DateTimeRange.Parse(">now/M", _now);
+        Assert.NotEqual(DateTimeRange.Empty, range);
+        Assert.Equal(_now.EndOfMonth(), range.Start);
+        Assert.Equal(DateTime.MaxValue, range.End);
+    }
+
+    [Fact]
+    public void Parse_LessThanOrEqualWithMonthRounding_RoundsCorrectly()
+    {
+        // <=now/M → inclusive upper → isUpperLimit=true → rounds to end of month
+        var range = DateTimeRange.Parse("<=now/M", _now);
+        Assert.NotEqual(DateTimeRange.Empty, range);
+        Assert.Equal(DateTime.MinValue, range.Start);
+        Assert.Equal(_now.EndOfMonth(), range.End);
+    }
+
+    [Theory]
+    [InlineData(">")]
+    [InlineData(">=")]
+    [InlineData("<")]
+    [InlineData("<=")]
+    [InlineData("> ")]
+    public void Parse_ComparisonOperatorWithoutExpression_ReturnsEmpty(string input)
+    {
+        var range = DateTimeRange.Parse(input, _now);
+        Assert.Equal(DateTimeRange.Empty, range);
+    }
 }

tests/Exceptionless.DateTimeExtensions.Tests/FormatParsers/TwoPartFormatParserTests.cs

@@ -51,18 +51,46 @@ public static IEnumerable<object[]> Inputs
                 ["{2012 TO 2013]",   _now.ChangeYear(2012).EndOfYear(), _now.ChangeYear(2013).EndOfYear()],
                 ["{jan TO feb]",     _now.ChangeMonth(1).EndOfMonth(), _now.ChangeMonth(2).EndOfMonth()],
 
-                // Wildcard support
+                // Wildcard support — wildcards always return min/max regardless of bracket type
                 ["* TO 2013",        DateTime.MinValue, _now.ChangeYear(2013).EndOfYear()],
                 ["2012 TO *",        _now.ChangeYear(2012).StartOfYear(), DateTime.MaxValue],
                 ["[* TO 2013]",      DateTime.MinValue, _now.ChangeYear(2013).EndOfYear()],
+                ["{* TO 2013}",      DateTime.MinValue, _now.ChangeYear(2013).StartOfYear()],
                 ["{2012 TO *}",      _now.ChangeYear(2012).EndOfYear(), DateTime.MaxValue],
+                ["[2012 TO *}",      _now.ChangeYear(2012).StartOfYear(), DateTime.MaxValue],
+
+                // Bracket-aware rounding with /d — all four bracket combinations
+                // [ = inclusive (gte) rounds to start of day, ] = inclusive (lte) rounds to end of day
+                // { = exclusive (gt) rounds to end of day, } = exclusive (lt) rounds to start of day
+                ["[now-7d/d TO now/d]",  _now.SubtractDays(7).StartOfDay(), _now.EndOfDay()],
+                ["{now-7d/d TO now/d}",  _now.SubtractDays(7).EndOfDay(), _now.StartOfDay()],
+                ["[now-7d/d TO now/d}",  _now.SubtractDays(7).StartOfDay(), _now.StartOfDay()],
+                ["{now-7d/d TO now/d]",  _now.SubtractDays(7).EndOfDay(), _now.EndOfDay()],
+
+                // Bracket-aware rounding with /M — all four bracket combinations
+                ["[now/M TO now+2M/M]",  _now.StartOfMonth(), _now.AddMonths(2).EndOfMonth()],
+                ["{now/M TO now+2M/M}",  _now.EndOfMonth(), _now.AddMonths(2).StartOfMonth()],
+                ["[now/M TO now+2M/M}",  _now.StartOfMonth(), _now.AddMonths(2).StartOfMonth()],
+                ["{now/M TO now+2M/M]",  _now.EndOfMonth(), _now.AddMonths(2).EndOfMonth()],
+
+                // Bracket-aware rounding with /h — all four bracket combinations
+                ["[now-3h/h TO now/h]",  _now.AddHours(-3).StartOfHour(), _now.EndOfHour()],
+                ["{now-3h/h TO now/h}",  _now.AddHours(-3).EndOfHour(), _now.StartOfHour()],
+                ["[now-3h/h TO now/h}",  _now.AddHours(-3).StartOfHour(), _now.StartOfHour()],
+                ["{now-3h/h TO now/h]",  _now.AddHours(-3).EndOfHour(), _now.EndOfHour()],
+
+                // Bracket-aware rounding with /y — all four bracket combinations
+                ["[now-2y/y TO now/y]",  _now.AddYears(-2).StartOfYear(), _now.EndOfYear()],
+                ["{now-2y/y TO now/y}",  _now.AddYears(-2).EndOfYear(), _now.StartOfYear()],
+                ["[now-2y/y TO now/y}",  _now.AddYears(-2).StartOfYear(), _now.StartOfYear()],
+                ["{now-2y/y TO now/y]",  _now.AddYears(-2).EndOfYear(), _now.EndOfYear()],
 
                 // Invalid inputs
                 ["blah",             null, null],
                 ["[invalid",         null, null],
                 ["invalid}",         null, null],
 
-                // Mismatched bracket validation
+                // Invalid bracket validation
                 ["}2012 TO 2013{",   null, null], // Wrong orientation
                 ["]2012 TO 2013[",   null, null], // Wrong orientation
                 ["[2012 TO 2013",    null, null], // Missing closing bracket