737 words
4 minutes
Expressive Code Example
2024-04-10

Here, we’ll explore how code blocks look using Expressive Code. The provided examples are based on the official documentation, which you can refer to for further details.

Expressive Code#

Syntax Highlighting#

Syntax Highlighting

Regular syntax highlighting#

console.log('This code is syntax highlighted!')

Rendering ANSI escape sequences#

Terminal window
ANSI colors:
- Regular: Red Green Yellow Blue Magenta Cyan
- Bold: Red Green Yellow Blue Magenta Cyan
- Dimmed: Red Green Yellow Blue Magenta Cyan
256 colors (showing colors 160-177):
160 161 162 163 164 165
166 167 168 169 170 171
172 173 174 175 176 177
Full RGB colors:
ForestGreen - RGB(34, 139, 34)
Text formatting: Bold Dimmed Italic Underline

Editor & Terminal Frames#

Editor & Terminal Frames

Code editor frames#

my-test-file.js
console.log('Title attribute example')

src/content/index.html
<div>File name comment example</div>

Terminal frames#

Terminal window
echo "This terminal frame has no title"

PowerShell terminal example
Write-Output "This one has a title!"

Overriding frame types#

echo "Look ma, no frame!"

PowerShell Profile.ps1
# Without overriding, this would be a terminal frame
function Watch-Tail { Get-Content -Tail 20 -Wait $args }
New-Alias tail Watch-Tail

Text & Line Markers#

Text & Line Markers

Marking full lines & line ranges#

// Line 1 - targeted by line number
// Line 2
// Line 3
// Line 4 - targeted by line number
// Line 5
// Line 6
// Line 7 - targeted by range "7-8"
// Line 8 - targeted by range "7-8"

Selecting line marker types (mark, ins, del)#

line-markers.js
function demo() {
console.log('this line is marked as deleted')
// This line and the next one are marked as inserted
console.log('this is the second inserted line')
return 'this line uses the neutral default marker type'
}

Adding labels to line markers#

labeled-line-markers.jsx
<button
role="button"
{...props}
value={value}
className={buttonClassName}
disabled={disabled}
active={active}
>
{children &&
!active &&
(typeof children === 'string' ? <span>{children}</span> : children)}
</button>

Adding long labels on their own lines#

labeled-line-markers.jsx
<button
role="button"
{...props}
value={value}
className={buttonClassName}
disabled={disabled}
active={active}
>
{children &&
!active &&
(typeof children === 'string' ? <span>{children}</span> : children)}
</button>

Using diff-like syntax#

this line will be marked as inserted
this line will be marked as deleted
this is a regular line

--- a/README.md
+++ b/README.md
@@ -1,3 +1,4 @@
+this is an actual diff file
-all contents will remain unmodified
no whitespace will be removed either

Combining syntax highlighting with diff-like syntax#

function thisIsJavaScript() {
// This entire block gets highlighted as JavaScript,
// and we can still add diff markers to it!
console.log('Old code to be removed')
console.log('New and shiny code!')
}

Marking individual text inside lines#

function demo() {
// Mark any given text inside lines
return 'Multiple matches of the given text are supported';
}

Regular expressions#

console.log('The words yes and yep will be marked.')

Escaping forward slashes#

Terminal window
echo "Test" > /home/test.txt

Selecting inline marker types (mark, ins, del)#

function demo() {
console.log('These are inserted and deleted marker types');
// The return statement uses the default marker type
return true;
}

Word Wrap#

Word Wrap

Configuring word wrap per block#

// Example with wrap
function getLongString() {
return 'This is a very long string that will most probably not fit into the available space unless the container is extremely wide'
}

// Example with wrap=false
function getLongString() {
return 'This is a very long string that will most probably not fit into the available space unless the container is extremely wide'
}

Configuring indentation of wrapped lines#

// Example with preserveIndent (enabled by default)
function getLongString() {
return 'This is a very long string that will most probably not fit into the available space unless the container is extremely wide'
}

// Example with preserveIndent=false
function getLongString() {
return 'This is a very long string that will most probably not fit into the available space unless the container is extremely wide'
}

Collapsible Sections#

Collapsible Sections

5 collapsed lines
// All this boilerplate setup code will be collapsed
import { someBoilerplateEngine } from '@example/some-boilerplate'
import { evenMoreBoilerplate } from '@example/even-more-boilerplate'
const engine = someBoilerplateEngine(evenMoreBoilerplate())
// This part of the code will be visible by default
engine.doSomething(1, 2, 3, calcFn)
function calcFn() {
// You can have multiple collapsed sections
3 collapsed lines
const a = 1
const b = 2
const c = a + b
// This will remain visible
console.log(`Calculation result: ${a} + ${b} = ${c}`)
return c
}
4 collapsed lines
// All this code until the end of the block will be collapsed again
engine.closeConnection()
engine.freeMemory()
engine.shutdown({ reason: 'End of example boilerplate code' })

Line Numbers#

Line Numbers

Displaying line numbers per block#

// This code block will show line numbers
console.log('Greetings from line 2!')
console.log('I am on line 3')

// Line numbers are disabled for this block
console.log('Hello?')
console.log('Sorry, do you know what line I am on?')

Changing the starting line number#

console.log('Greetings from line 5!')
console.log('I am on line 6')
Expressive Code Example
https://blog.tantalum.life/posts/expressive-code/
Author
Zokiio
Published at
2024-04-10
License
CC BY-NC-SA 4.0