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14
README.md
14
README.md
@@ -10,7 +10,11 @@ pairing with smart people at Hashrocket.
|
|||||||
|
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For a steady stream of TILs, [sign up for my newsletter](https://crafty-builder-6996.ck.page/e169c61186).
|
For a steady stream of TILs, [sign up for my newsletter](https://crafty-builder-6996.ck.page/e169c61186).
|
||||||
|
|
||||||
_1552 TILs and counting..._
|
_1555 TILs and counting..._
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||||||
|
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||||||
|
See some of the other learning resources I work on:
|
||||||
|
- [Ruby Operator Lookup](https://www.visualmode.dev/ruby-operators)
|
||||||
|
- [Vim Un-Alphabet](https://www.youtube.com/playlist?list=PL46-cKSxMYYCMpzXo6p0Cof8hJInYgohU)
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||||||
|
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||||||
---
|
---
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@@ -403,9 +407,11 @@ _1552 TILs and counting..._
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|||||||
|
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- [Access Go Docs Offline](go/access-go-docs-offline.md)
|
- [Access Go Docs Offline](go/access-go-docs-offline.md)
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- [Add A Method To A Struct](go/add-a-method-to-a-struct.md)
|
- [Add A Method To A Struct](go/add-a-method-to-a-struct.md)
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||||||
|
- [Basic Delve Debugging Session](go/basic-delve-debugging-session.md)
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||||||
- [Build For A Specific OS And Architecture](go/build-for-a-specific-os-and-architecture.md)
|
- [Build For A Specific OS And Architecture](go/build-for-a-specific-os-and-architecture.md)
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||||||
- [Check If Cobra Flag Was Set](go/check-if-cobra-flag-was-set.md)
|
- [Check If Cobra Flag Was Set](go/check-if-cobra-flag-was-set.md)
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||||||
- [Combine Two Slices](go/combine-two-slices.md)
|
- [Combine Two Slices](go/combine-two-slices.md)
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|
- [Connect To A SQLite Database](go/connect-to-a-sqlite-database.md)
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- [Create A Slice From An Array](go/create-a-slice-from-an-array.md)
|
- [Create A Slice From An Array](go/create-a-slice-from-an-array.md)
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- [Detect If Stdin Comes From A Redirect](go/detect-if-stdin-comes-from-a-redirect.md)
|
- [Detect If Stdin Comes From A Redirect](go/detect-if-stdin-comes-from-a-redirect.md)
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||||||
- [Deterministically Seed A Random Number Generator](go/deterministically-seed-a-random-number-generator.md)
|
- [Deterministically Seed A Random Number Generator](go/deterministically-seed-a-random-number-generator.md)
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@@ -1269,6 +1275,7 @@ _1552 TILs and counting..._
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- [Iterate With An Offset Index](ruby/iterate-with-an-offset-index.md)
|
- [Iterate With An Offset Index](ruby/iterate-with-an-offset-index.md)
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- [Include Extra Context In A Honeybadger Notify](ruby/include-extra-context-in-a-honeybadger-notify.md)
|
- [Include Extra Context In A Honeybadger Notify](ruby/include-extra-context-in-a-honeybadger-notify.md)
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- [Ins And Outs Of Pry](ruby/ins-and-outs-of-pry.md)
|
- [Ins And Outs Of Pry](ruby/ins-and-outs-of-pry.md)
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|
- [Install Latest Version Of Ruby With asdf](ruby/install-latest-version-of-ruby-with-asdf.md)
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- [Invoking Rake Tasks Multiple Times](ruby/invoking-rake-tasks-multiple-times.md)
|
- [Invoking Rake Tasks Multiple Times](ruby/invoking-rake-tasks-multiple-times.md)
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- [IRB Has Built-In Benchmarking With Ruby 3](ruby/irb-has-built-in-benchmarking-with-ruby-3.md)
|
- [IRB Has Built-In Benchmarking With Ruby 3](ruby/irb-has-built-in-benchmarking-with-ruby-3.md)
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- [Jump Out Of A Nested Context With Throw/Catch](ruby/jump-out-of-a-nested-context-with-throw-catch.md)
|
- [Jump Out Of A Nested Context With Throw/Catch](ruby/jump-out-of-a-nested-context-with-throw-catch.md)
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@@ -1301,6 +1308,7 @@ _1552 TILs and counting..._
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- [Question Mark Operator](ruby/question-mark-operator.md)
|
- [Question Mark Operator](ruby/question-mark-operator.md)
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- [Rake Only Lists Tasks With Descriptions](ruby/rake-only-lists-tasks-with-descriptions.md)
|
- [Rake Only Lists Tasks With Descriptions](ruby/rake-only-lists-tasks-with-descriptions.md)
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- [Read The First Line From A File](ruby/read-the-first-line-from-a-file.md)
|
- [Read The First Line From A File](ruby/read-the-first-line-from-a-file.md)
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|
- [Refer To Implicit Block Argument With It](ruby/refer-to-implicit-block-argument-with-it.md)
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- [Rendering ERB](ruby/rendering-erb.md)
|
- [Rendering ERB](ruby/rendering-erb.md)
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- [Replace The Current Process With An External Command](ruby/replace-the-current-process-with-an-external-command.md)
|
- [Replace The Current Process With An External Command](ruby/replace-the-current-process-with-an-external-command.md)
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- [Require Entire Gemfile In Pry Session](ruby/require-entire-gemfile-in-pry-session.md)
|
- [Require Entire Gemfile In Pry Session](ruby/require-entire-gemfile-in-pry-session.md)
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@@ -1856,11 +1864,11 @@ I shamelessly stole this idea from
|
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|
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* [Today I Learned by Hashrocket](https://til.hashrocket.com)
|
* [Today I Learned by Hashrocket](https://til.hashrocket.com)
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* [jwworth/til](https://github.com/jwworth/til)
|
* [jwworth/til](https://github.com/jwworth/til)
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* [thoughtbot/til](https://github.com/thoughtbot/til)
|
* [til.simonwillison.net](https://til.simonwillison.net/)
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|
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## License
|
## License
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|
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© 2015-2022 Josh Branchaud
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© 2015-2025 Josh Branchaud
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|
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This repository is licensed under the MIT license. See `LICENSE` for
|
This repository is licensed under the MIT license. See `LICENSE` for
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details.
|
details.
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|
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63
go/basic-delve-debugging-session.md
Normal file
63
go/basic-delve-debugging-session.md
Normal file
@@ -0,0 +1,63 @@
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|
# Basic Delve Debugging Session
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|
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|
When using [delve](https://github.com/go-delve/delve) to debug a Go program,
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|
these are the series of things I usually find myself doing.
|
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|
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|
First, I start running the program with `dlv` including any arguments after a `--` (in my case, the `solve` subcommand and a filename).
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|
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|
```bash
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|
$ dlv debug . -- solve samples/001.txt
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|
```
|
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|
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|
`dlv` starts up and is ready to run my program from the beginning. I'll need to
|
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|
set a couple breakpoints before continuing. I do this with the `break` command,
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|
specifying the filename and line number.
|
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|
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|
```
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|
(dlv) break main.go:528
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|
Breakpoint 1 set at 0x10c1a5bea for main.traversePuzzleIterative() ./main.go:528
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|
(dlv) break main.go:599
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|
Breakpoint 2 set at 0x10c1a6dcc for main.traversePuzzleIterative() ./main.go:599
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|
```
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|
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|
Now I can continue which will run the program until hitting a breakpoint.
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|
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|
```
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|
(dlv) continue
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|
> [Breakpoint 2] main.traversePuzzleIterative() ./main.go:599 (hits goroutine(1):1 total:1) (PC: 0x10c1a6dcc)
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|
594: }
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|
595: }
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||||||
|
596:
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|
597: topStackFrame := stack[len(stack)-1]
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|
598: // if the current stack frame has more values, try the next
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|
=> 599: if len(topStackFrame.PossibleValues) > 0 {
|
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|
600: nextValue := topStackFrame.PossibleValues[0]
|
||||||
|
601: topStackFrame.PossibleValues = topStackFrame.PossibleValues[1:]
|
||||||
|
602: topStackFrame.CurrValue = nextValue
|
||||||
|
603:
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|
604: // Undo the last placement and make a new one
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|
```
|
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|
|
||||||
|
I can see the context around the line we've stopped on. From here I can dig
|
||||||
|
into the current state of the program by looking at local variables (`locals`)
|
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|
or printing out a specific value (`print someVar`). I can continue to step
|
||||||
|
through the program line by line with `next` or eventually run `continue` to
|
||||||
|
proceed to the next breakpoint.
|
||||||
|
|
||||||
|
```
|
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|
(dlv) locals
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|
diagnostics = main.Diagnostics {BacktrackCount: 0, NodeVisitCount: 1, ValidityCheckCount: 2,...+2 more}
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|
stack = []main.StackData len: 1, cap: 1, [...]
|
||||||
|
emptyCellPositions = [][]int len: 3, cap: 4, [...]
|
||||||
|
emptyCellIndex = 1
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|
status = "Invalid"
|
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|
topStackFrame = main.StackData {RowIndex: 1, ColumnIndex: 7, PossibleValues: []int len: 8, cap: 8, [...],...+1 more}
|
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|
(dlv) print topStackFrame
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|
main.StackData {
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|
RowIndex: 1,
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|
ColumnIndex: 7,
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||||||
|
PossibleValues: []int len: 8, cap: 8, [2,3,4,5,6,7,8,9],
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|
CurrValue: 1,}
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|
(dlv) next
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|
> main.traversePuzzleIterative() ./main.go:600 (PC: 0x10c1a6dea)
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||||||
|
```
|
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50
go/connect-to-a-sqlite-database.md
Normal file
50
go/connect-to-a-sqlite-database.md
Normal file
@@ -0,0 +1,50 @@
|
|||||||
|
# Connect To A SQLite Database
|
||||||
|
|
||||||
|
Using the `database/sql` module and the `github.com/mattn/go-sqlite3` package,
|
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|
we can connect to a SQLite database and run some queries. In my case, I have a
|
||||||
|
SQLite connection string exported to my environment, so I can access that with
|
||||||
|
`os.Getenv`. It's a local SQLite file, `./test.db`.
|
||||||
|
|
||||||
|
Calling `sql.Open`, I'm able to connect with a SQLite3 driver to the database
|
||||||
|
at that connection string. The `setupDatabase` function returns that database
|
||||||
|
connection pointer. Things like `Exec` and `QueryRow` can be called on `db`. I
|
||||||
|
also need to make sure I close the connection to the database with a `defer`.
|
||||||
|
|
||||||
|
Here is a full example of connecting to a local SQLite database and inserting a
|
||||||
|
record:
|
||||||
|
|
||||||
|
```go
|
||||||
|
package main
|
||||||
|
|
||||||
|
import (
|
||||||
|
"database/sql"
|
||||||
|
"fmt"
|
||||||
|
"os"
|
||||||
|
|
||||||
|
_ "github.com/mattn/go-sqlite3"
|
||||||
|
)
|
||||||
|
|
||||||
|
func setupDatabase() *sql.DB {
|
||||||
|
databaseString := os.Getenv("GOOSE_DBSTRING")
|
||||||
|
if len(databaseString) == 0 {
|
||||||
|
fmt.Println("Error retrieving `GOOSE_DBSTRING` from env")
|
||||||
|
os.Exit(1)
|
||||||
|
}
|
||||||
|
db, err := sql.Open("sqlite3", databaseString)
|
||||||
|
if err != nil {
|
||||||
|
fmt.Printf("Error opening database: %v\n", err)
|
||||||
|
os.Exit(1)
|
||||||
|
}
|
||||||
|
|
||||||
|
return db
|
||||||
|
}
|
||||||
|
|
||||||
|
func main() {
|
||||||
|
db := setupDatabase()
|
||||||
|
defer db.Close()
|
||||||
|
|
||||||
|
sql := `insert into users (name) values (?);`
|
||||||
|
|
||||||
|
db.Exec(sql, "Josh")
|
||||||
|
}
|
||||||
|
```
|
||||||
@@ -5,6 +5,8 @@ an array-like object with all of the arguments to the function. Even if not
|
|||||||
all of the arguments are referenced in the function signature, they can
|
all of the arguments are referenced in the function signature, they can
|
||||||
still be accessed via the `arguments` object.
|
still be accessed via the `arguments` object.
|
||||||
|
|
||||||
|
> For ES6+ compatibility, the `spread` operator used via [rest parameters](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/rest_parameters) is preferred over the `arugments` object when accessing an abritrary number of function arguments.
|
||||||
|
|
||||||
```javascript
|
```javascript
|
||||||
function argTest(one) {
|
function argTest(one) {
|
||||||
console.log(one);
|
console.log(one);
|
||||||
|
|||||||
54
ruby/install-latest-version-of-ruby-with-asdf.md
Normal file
54
ruby/install-latest-version-of-ruby-with-asdf.md
Normal file
@@ -0,0 +1,54 @@
|
|||||||
|
# Install Latest Version Of Ruby With asdf
|
||||||
|
|
||||||
|
When I check the `asdf` Ruby plugin for known versions of Ruby:
|
||||||
|
|
||||||
|
```bash
|
||||||
|
$ asdf list-all ruby | fzf
|
||||||
|
```
|
||||||
|
|
||||||
|
I don't find the latest (`3.4`).
|
||||||
|
|
||||||
|
I need to update the plugin. A newer version of the plugin will know about
|
||||||
|
newer Ruby versions.
|
||||||
|
|
||||||
|
```bash
|
||||||
|
$ asdf plugin-update ruby
|
||||||
|
```
|
||||||
|
|
||||||
|
Now, if I run the `list-all` command again, I'll find the version I'm looking
|
||||||
|
for — `3.4.1`.
|
||||||
|
|
||||||
|
Now that `asdf` and I both know about the version to be installed, I can tell
|
||||||
|
`asdf` to install it:
|
||||||
|
|
||||||
|
```bash
|
||||||
|
$ asdf install ruby 3.4.1
|
||||||
|
```
|
||||||
|
|
||||||
|
Now, if I check the current Ruby version, I'll see that it is still set to some
|
||||||
|
other version.
|
||||||
|
|
||||||
|
```bash
|
||||||
|
$ ruby --version
|
||||||
|
ruby 3.2.2 (2023-03-30 revision e51014f9c0) [x86_64-darwin22]
|
||||||
|
```
|
||||||
|
|
||||||
|
I need to tell `asdf` to start using this newly installed version instead,
|
||||||
|
either globally or locally.
|
||||||
|
|
||||||
|
```bash
|
||||||
|
$ # globally
|
||||||
|
$ asdf global ruby 3.4.1
|
||||||
|
$ # or locally
|
||||||
|
$ asdf local ruby 3.4.1
|
||||||
|
```
|
||||||
|
|
||||||
|
And now I'm all set:
|
||||||
|
|
||||||
|
```bash
|
||||||
|
$ asdf current ruby
|
||||||
|
ruby 3.4.1 /Users/jbranchaud/.tool-versions
|
||||||
|
|
||||||
|
$ ruby --version
|
||||||
|
ruby 3.4.1 (2024-12-25 revision 48d4efcb85) +PRISM [x86_64-darwin22]
|
||||||
|
```
|
||||||
43
ruby/refer-to-implicit-block-argument-with-it.md
Normal file
43
ruby/refer-to-implicit-block-argument-with-it.md
Normal file
@@ -0,0 +1,43 @@
|
|||||||
|
# Refer To Implicit Block Argument With It
|
||||||
|
|
||||||
|
One of the key features of the Ruby 3.4 release is the `it` implicit block
|
||||||
|
argument.
|
||||||
|
|
||||||
|
The vast majority of inline blocks defined in Ruby code receive a single block
|
||||||
|
argument. Typically we name and reference a block argument explictly like so:
|
||||||
|
|
||||||
|
```ruby
|
||||||
|
items.map { |item| item * item }
|
||||||
|
```
|
||||||
|
|
||||||
|
Ruby likes to cut away excess syntax when possible. To that end, the implicit
|
||||||
|
`it` block argument has been added. This is an identifier we can reference in
|
||||||
|
the context of a block and its value is the current
|
||||||
|
|
||||||
|
```ruby
|
||||||
|
items = [1,2,3,4,5]
|
||||||
|
|
||||||
|
squares = items.map { it * it }
|
||||||
|
|
||||||
|
pp squares
|
||||||
|
#=> [1, 4, 9, 16, 25]
|
||||||
|
```
|
||||||
|
|
||||||
|
Note: we cannot mix numbered parameters (`_1`, `_2`) with the `it` parameter.
|
||||||
|
If we do, we'll get the following error:
|
||||||
|
|
||||||
|
```ruby
|
||||||
|
def method_using_block(a, b)
|
||||||
|
yield(a, b) if block_given?
|
||||||
|
end
|
||||||
|
|
||||||
|
puts method_using_block(4,5) { _2 ** _1 } #=> 625
|
||||||
|
puts method_using_block(4,5) { _2 ** it }
|
||||||
|
# it_block.rb:12: syntax error found (SyntaxError)
|
||||||
|
# 10 |
|
||||||
|
# 11 | puts method_using_block(4,5) { _2 ** _1 }
|
||||||
|
# > 12 | ... it }
|
||||||
|
# | ^~ `it` is not allowed when a numbered parameter is already used
|
||||||
|
```
|
||||||
|
|
||||||
|
[source](https://docs.ruby-lang.org/en/3.4/NEWS_md.html)
|
||||||
Reference in New Issue
Block a user