Message Handling with Boolean Algebra Ben Deane / CppCon / 2024-09-16 1Alternative Title "The Unreasonable Effectiveness of Boolean Algebra in Software Design, Showing the Particular Application of identifying (with matchers) a message coming off the wire. The role of Boolean algebra in composing matchers. Understanding Boolean implication and using it to simplify matchers. This talk is a series less_than_t = relational_matcher_t, Field, Value>; 6: 7: // etc... 22Matchers are Boolean values We can treat a function that returns a bool just like a bool. (They're isomorphic.) All

getting and setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263 10.10 Boolean indexing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . is_quarter_end, is_year_start, is_year_end accessors for DateTimeIndex / Timestamp which return a boolean array of whether the timestamp(s) are at the start/end of the month/quarter/year defined by the frequency using the Series name or numbering columns as needed (GH2385). See the docs • Slicing and advanced/boolean indexing operations on Index classes as well as Index.delete() and Index.drop() methods will no

getting and setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348 12.10 Boolean indexing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . exact defaults to True (meaning that exact matching is still the default) (GH8904) • Added axvlines boolean option to parallel_coordinates plot function, determines whether vertical lines will be printed, different data type (GH8833) • Bug in slicing a multi-index with an empty list and at least one boolean indexer (GH8781) • io.data.Options now raises RemoteDataError when no expiry dates are available

getting and setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235 10.10 Boolean indexing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . to (GH1073, GH4633) behavior. See gotchas for a more detailed discussion. This prevents doing boolean comparison on entire pandas objects, which is inherently ambiguous. These all will raise a ValueError s1 and s2 Added the .bool() method to NDFrame objects to facilitate evaluating of single-element boolean Series: In [1]: Series([True]).bool() Out[1]: True In [2]: Series([False]).bool() Out[2]: False

getting and setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340 12.10 Boolean indexing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . in groupby .nth with a Series and integer-like column name (GH7559) • Bug in Series.get with a boolean accessor (GH7407) • Bug in value_counts where NaT did not qualify as missing (NaN) (GH7423) 38 rolling_cov, and rolling_corr for two arguments with mismatched index (GH7512) • Bug in to_sql taking the boolean column as text column (GH7678) • Bug in grouped hist doesn’t handle rot kw and sharex kw properly

getting and setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 422 13.10 Boolean indexing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . to_timedelta * Error handling * Consistent Parsing – Changes to Index Comparisons – Changes to Boolean Comparisons vs. None – HDFStore dropna behavior – Changes to display.precision option – Changes to done: In [70]: np.array([1, 2, 3]) == np.array([1, 2]) Out[70]: False Changes to Boolean Comparisons vs. None Boolean comparisons of a Series vs None will now be equivalent to comparing with np.nan, rather

. . . . . . . . . . 1310 74.3.49 in(string,):Boolean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1311 74.3.50 in(UnicodeString,):Boolean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1452 75.11.102equal(variant,variant):Boolean . . . . . . . . . . . . . . . . . . . . . . . 1453 75.11.103Erase . . . . . . . . . . . . . . . . 1475 75.11.161greaterthan(variant,variant):Boolean . . . . . . . . . . . . . . . . . . . . 1475 75.11.162greaterthanorequal(variant,variant):Boolean . . . . . . . . . . . . . . . . 1475 75.11.163Halt

following to get the machine’s name: IMachine machine = ...; String name = machine.getName(); Boolean attribute getters can sometimes be called isAttribute() due to JAX-WS naming conventions. 3.2 Changing 32 5 Classes (interfaces) 5.2.1 Attributes 5.2.1.1 midlDoesNotLikeEmptyInterfaces (read-only) boolean IAdditionsStateChangedEvent::midlDoesNotLikeEmptyInterfaces 5.3 IAppliance Represents a platform-independent virtual machine. Used in IAudioSettings::adapter. 5.4.1 Attributes 5.4.1.1 enabled (read/write) boolean IAudioAdapter::enabled Flag whether the audio adapter is present in the guest system. If disabled

following to get the machine’s name: IMachine machine = ...; String name = machine.getName(); Boolean attribute getters can sometimes be called isAttribute() due to JAX-WS naming conventions. 9 Changing lviii Classes (interfaces) 13.1 Attributes 13.1.1 midlDoesNotLikeEmptyInterfaces (read-only) boolean IAdditionsStateChangedEvent::midlDoesNotLikeEmptyInterfaces 14 IAppliance Represents a platform-independent virtual machine. Used in IAudioSettings::adapter. 15.1 Attributes 15.1.1 enabled (read/write) boolean IAudioAdapter::enabled Flag whether the audio adapter is present in the guest system. If disabled

following to get the machine’s name: IMachine machine = ...; String name = machine.getName(); Boolean attribute getters can sometimes be called isAttribute() due to JAX-WS naming conventions. 3.2 Changing 58 5 Classes (interfaces) 5.2.1 Attributes 5.2.1.1 midlDoesNotLikeEmptyInterfaces (read-only) boolean IAdditionsStateChangedEvent::midlDoesNotLikeEmptyInterfaces 5.3 IAppliance Represents a platform-independent virtual machine. Used in IAudioSettings::adapter. 5.4.1 Attributes 5.4.1.1 enabled (read/write) boolean IAudioAdapter::enabled Flag whether the audio adapter is present in the guest system. If disabled