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# Description This PR adds lazy closure evaluation to the `default` command (closes #14160). - For non-closure values and without providing a column name, `default` acts the same as before - The user can now provide multiple column names to populate if empty - If the user provides a column name, the input must be a record or list, otherwise an error is created. - The user can now provide a closure as a default value - This closure is run without any arguments or input - The closure is never evaluated if the value isn't needed - Even when column names are supplied, the closure is only run once (and cached to prevent re-calling it) For example: ```nushell > default { 1 + 2 } # => 3 > null | default 3 a # => previously `null`, now errors > 1 | default { sleep 5sec; 3 } # => `1`, without waiting 5 seconds > let optional_var = null; $optional_var | default { input 'Enter value: ' } # => Returns user input > 5 | default { input 'Enter value: ' } # => `5`, without prompting user > ls | default { sleep 5sec; 'N/A' } name # => No-op since `name` column is never empty > ls | default { sleep 5sec; 'N/A' } foo bar # => creates columns `foo` and `bar`; only takes 5 seconds since closure result is cached # Old behavior is the same > [] | default 'foo' # => [] > [] | default --empty 'foo' # => 'foo' > default 5 # => 5 ``` # User-Facing Changes - Users can add default values to multiple columns now. - Users can now use closures as the default value passed to `default`. - To return a closure, the user must wrap the closure they want to return inside another closure, which will be run (`default { $my_closure }`). # Tests + Formatting All tests pass. # After Submitting --------- Co-authored-by: 132ikl <132@ikl.sh> |
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| .. | ||
| nu_plugin_custom_values | ||
| nu_plugin_example | ||
| nu_plugin_formats | ||
| nu_plugin_gstat | ||
| nu_plugin_inc | ||
| nu_plugin_javascript | ||
| nu_plugin_nu_example | ||
| nu_plugin_polars | ||
| nu_plugin_python | ||
| nu_plugin_query | ||
| nu_plugin_stress_internals | ||
| nu-cli | ||
| nu-cmd-base | ||
| nu-cmd-extra | ||
| nu-cmd-lang | ||
| nu-cmd-plugin | ||
| nu-color-config | ||
| nu-command | ||
| nu-derive-value | ||
| nu-engine | ||
| nu-explore | ||
| nu-glob | ||
| nu-json | ||
| nu-lsp | ||
| nu-parser | ||
| nu-path | ||
| nu-plugin | ||
| nu-plugin-core | ||
| nu-plugin-engine | ||
| nu-plugin-protocol | ||
| nu-plugin-test-support | ||
| nu-pretty-hex | ||
| nu-protocol | ||
| nu-std | ||
| nu-system | ||
| nu-table | ||
| nu-term-grid | ||
| nu-test-support | ||
| nu-utils | ||
| nuon | ||
| README.md | ||
Nushell core libraries and plugins
These sub-crates form both the foundation for Nu and a set of plugins which extend Nu with additional functionality.
Foundational libraries are split into two kinds of crates:
- Core crates - those crates that work together to build the Nushell language engine
- Support crates - a set of crates that support the engine with additional features like JSON support, ANSI support, and more.
Plugins are likewise also split into two types:
- Core plugins - plugins that provide part of the default experience of Nu, including access to the system properties, processes, and web-connectivity features.
- Extra plugins - these plugins run a wide range of different capabilities like working with different file types, charting, viewing binary data, and more.