Merge bea8f291bc into 770a4138b4

.github/PULL_REQUEST_TEMPLATE.md

@@ -3,4 +3,3 @@
 - [ ] Pull request touches only one file (or a set of logically related files with similar changes made)
 - [ ] Content changes are aimed at *intermediate to experienced programmers* (this is a poor format for explaining fundamental programming concepts)
 - [ ] If you've changed any part of the YAML Frontmatter, make sure it is formatted according to [CONTRIBUTING.md](https://github.com/adambard/learnxinyminutes-docs/blob/master/CONTRIBUTING.md)
-  - [ ] Yes, I have double-checked quotes and field names!

.github/workflows/lint.yml

@@ -11,8 +11,18 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.13'
+      - run: pip install -r lint/requirements.txt
       - uses: ruby/setup-ruby@v1
         with:
           ruby-version: '3.2'
       - run: gem install mdl
-      - run: mdl . --ignore-front-matter -r MD003,MD011,MD023,MD027,MD028,MD035,MD037,MD038,MD039,MD047
+
+      - name: Files are UTF-8
+        run: ./lint/encoding.sh .
+      - name: Lint Markdown
+        run: mdl . --ignore-front-matter -r MD003,MD011,MD023,MD027,MD028,MD035,MD037,MD038,MD039,MD047
+      - name: Lint frontmatter
+        run: ./lint/frontmatter.py .

CONTRIBUTING.md

@@ -31,13 +31,6 @@ review them more effectively and/or individually.
      language in question.
    * Keep articles succinct and scannable. We all know how to use Google here.
 * **Use UTF-8**
-   * For translations (or EN articles with non-ASCII characters) please ensure
-     your file is UTF-8 encoded.
-   * Leave out the byte-order-mark (BOM) at the start of the file (in Vim, use
-     `:set nobomb`).
-   * You can check if the file contains a BOM on Linux/Unix systems by running
-    `file language.html.markdown`  You will see this if it uses a BOM:
-    `UTF-8 Unicode (with BOM) text`.
 
 ### Header configuration
 
@@ -48,29 +41,32 @@ called frontmatter.
 The following fields are necessary for English articles about programming
 languages:
 
-* **name** The human-readable name of the programming language
-* **contributors** A list of [author, URL] lists to credit
+* `name`: The human-readable name of the programming language
+* `contributors`: A list of [*author*, *URL*] lists to credit, *URL* is optional
 
 Other fields:
 
-* **category**: The category of the article. So far, can be one of *language*,
+* `category`: The category of the article. So far, can be one of *language*,
   *tool* or *Algorithms & Data Structures*. Defaults to *language* if omitted.
-* **filename**: The filename for this article's code. It will be fetched, mashed
+* `filename`: The filename for this article's code. It will be fetched, mashed
   together, and made downloadable.
 
+Translations should also include:
+* `translators`: A list of [*translator*, *URL*] lists to credit, *URL* is optional
+
 Non-English articles inherit frontmatter values from the English article (if it exists)
 but you can overwrite them.
 
 Here's an example header for Ruby:
 
 ```yaml
-*--
+---
 name: Ruby
 filename: learnruby.rb
 contributors:
     - ["Doktor Esperanto", "http://example.com/"]
     - ["Someone else", "http://someoneelseswebsite.com/"]
-*--
+---
 ```
 
 ### Syntax highlighter

bf.md

@@ -1,6 +1,6 @@
 ---
 name: BF
-learn_x_in_y_name: brainfuck
+where_x_eq_name: brainfuck
 filename: bf.bf
 contributors:
     - ["Prajit Ramachandran", "http://prajitr.github.io/"]

ca/groovy.md

@@ -2,7 +2,7 @@
 filename: learngroovy-ca.groovy
 contributors:
     - ["Roberto Pérez Alcolea", "http://github.com/rpalcolea"]
-translations:
+translators:
     - ["Xavier Sala Pujolar", "http://github.com/utrescu"]
 ---
 

de/markdown.md

@@ -1,7 +1,7 @@
 ---
 contributors:
     - ["Dan Turkel", "http://danturkel.com/"]
-translators :
+translators:
     - ["Frederik Ring", "https://github.com/m90"]
     - ["Philipp Fischbeck", "https://github.com/PFischbeck"]
 filename: markdown-de.md

es/elixir.md

@@ -3,10 +3,9 @@ contributors:
     - ["Joao Marques", "http://github.com/mrshankly"]
     - ["Dzianis Dashkevich", "https://github.com/dskecse"]
     - ["Ryan Plant", "https://github.com/ryanplant-au"]
-translator:
+translators:
     - ["Adrian Carrascal", "https://github.com/acarrascalgarcia"]
 filename: learnelixir-es.ex
-
 ---
 
 Elixir es un lenguaje funcional moderno construido sobre la máquina virtual de Erlang.

es/git.md

@@ -2,9 +2,8 @@
 filename: LearnGit-es.txt
 contributors:
     - ["Jake Prather", "http://github.com/JakeHP"]
-translator:
+translators:
     - ["Raúl Ascencio", "http://rscnt.github.io"]
-
 ---
 
 Git es un sistema de control de versiones distribuido diseñado para manejar

fr/elixir.md

@@ -4,10 +4,11 @@ contributors:
     - ["Dzianis Dashkevich", "https://github.com/dskecse"]
     - ["Ryan Plant", "https://github.com/ryanplant-au"]
     - ["Ev Bogdanov", "https://github.com/evbogdanov"]
-translator:
+translators:
     - ["Timothé Pardieu", "https://github.com/timprd"]
 filename: learnelixir-fr.ex
 ---
+
 Elixir est un langage de programmation fonctionnel moderne reposant sur la machine virtuelle BEAM, qui héberge aussi Erlang.
 Il est totalement compatible avec Erlang mais dispose d'une syntaxe plus agréable et apporte de nouvelles fonctionnalités.
 

groovy.md

@@ -1,6 +1,5 @@
 ---
 name: Groovy
-filename: learngroovy.groovy
 contributors:
     - ["Roberto Pérez Alcolea", "http://github.com/rpalcolea"]
 filename: learngroovy.groovy

it/php-composer.md

@@ -1,7 +1,7 @@
 ---
 contributors:
     - ["Brett Taylor", "https://github.com/glutnix"]
-translator:
+translators:
     - ["Agostino Fiscale", "https://github.com/agostinofiscale"]
 filename: LearnComposer-it.sh
 ---

lint/encoding.sh

@@ -0,0 +1,30 @@
+#!/bin/bash
+
+check_encoding() {
+    file="$1"
+    encoding=$(file -b --mime-encoding "$file")
+
+    # Check if the encoding is neither UTF-8 nor US-ASCII
+    if [[ "$encoding" != "utf-8" && "$encoding" != "us-ascii" ]]; then
+        # Print the file path and encoding
+        echo "Error: $file has encoding $encoding, which is not utf-8 or us-ascii"
+        return 1
+    fi
+
+    # Check for UTF-8 BOM
+    if [[ "$encoding" == "utf-8" ]]; then
+        if head -c 3 "$file" | cmp -s <(echo -ne '\xEF\xBB\xBF'); then
+            echo "Error: $file contains a UTF-8 BOM"
+            return 1
+        fi
+    fi
+
+    return 0
+}
+
+export -f check_encoding
+
+# Default to current directory if no argument is given
+directory="${1:-.}"
+
+find "$directory" -type f -name "*.md" -print0 | xargs -0 -P 8 -I {} bash -c 'check_encoding "$@"' _ {}

lint/frontmatter.py

@@ -0,0 +1,120 @@
+#!/usr/bin/env python3
+
+import re
+from pathlib import Path
+import yaml
+import yamllint.config
+import yamllint.linter
+
+
+def extract_yaml_frontmatter(file_path):
+    """Extracts YAML front matter from a Markdown file."""
+    with open(file_path, "r", encoding="utf-8") as file:
+        content = file.read()
+        matches = re.match(r"^(---\s*\n.*?\n)---\n", content, re.DOTALL)
+        if matches:
+            return matches.group(1)
+        return None
+
+
+yaml_config = yamllint.config.YamlLintConfig(
+    """{
+        extends: relaxed, 
+        rules: {
+            commas: disable,
+            trailing-spaces: disable,
+            indentation: disable,
+            line-length: disable,
+            empty-lines: disable
+        } 
+    }"""
+)
+
+
+def lint_yaml(yaml_content):
+    """Lints YAML content using yamllint by sending it to stdin."""
+    problems = []
+    for p in yamllint.linter.run(yaml_content, yaml_config):
+        problems.append(f"{p.line}:{p.column}    {p.desc} ({p.rule})")
+    return "\n".join(problems)
+
+
+def validate_yaml_keys(yaml_content, allowed_keys):
+    """Validates that the YAML content contains only the specified keys."""
+    try:
+        data = yaml.safe_load(yaml_content)
+        if not data:
+            return "Empty YAML front matter."
+        extra_keys = set(data.keys()) - set(allowed_keys)
+        if extra_keys:
+            return f"Invalid keys found: {', '.join(extra_keys)}"
+        for key, value_type in allowed_keys.items():
+            if key in data:
+                if not isinstance(data[key], value_type):
+                    return f"Invalid type for key '{key}': expected {value_type.__name__}, got {type(data[key]).__name__}"
+                if isinstance(data[key], list):
+                    for item in data[key]:
+                        if not isinstance(item, list):
+                            return f"Invalid type for item in key '{key}': expected list, got {type(item).__name__}"
+                        elif not item:
+                            return f"Invalid item in key '{key}': found empty list"
+                        elif not isinstance(item[0], str):
+                            return f"Invalid type for item[0] in key '{key}': expected str, got {type(item[0]).__name__}"
+                        elif len(item) == 2 and not isinstance(item[1], str):
+                            return f"Invalid type for item[1] in key '{key}': expected str, got {type(item[1]).__name__}"
+                        elif len(item) > 2:
+                            return f"Invalid length for item in key '{key}': expected 1 or 2, got {len(item)}"
+    except yaml.YAMLError as e:
+        return f"Error parsing YAML: {e}"
+    return ""
+
+
+def process_files(path):
+    """Processes either a single file or all Markdown files in a directory."""
+    if path.is_dir():
+        pathlist = path.rglob("*.md")
+    else:
+        pathlist = [path]
+
+    has_error = False
+    allowed_keys = {
+        "name": str,
+        "where_x_eq_name": str,
+        "category": str,
+        "filename": str,
+        "contributors": list,
+        "translators": list,
+    }
+    for path in pathlist:
+        yaml_content = extract_yaml_frontmatter(path)
+        if yaml_content:
+            lint_result = lint_yaml(yaml_content)
+            key_validation = validate_yaml_keys(yaml_content, allowed_keys)
+            if lint_result or key_validation:
+                if has_error:  # don't prepend newline to first error
+                    print()
+                print(path)
+                if lint_result:
+                    print(lint_result)
+                if key_validation:
+                    print(key_validation)
+                has_error = True
+    return has_error
+
+
+def main(path_input):
+    """Determines if the input is a directory or a file and processes accordingly."""
+    path = Path(path_input)
+    if not path.exists():
+        print(f"Error: {path_input} does not exist.")
+        return 1
+
+    return process_files(path)
+
+
+if __name__ == "__main__":
+    import sys
+
+    path_input = sys.argv[1] if len(sys.argv) > 1 else "."
+    has_error = main(path_input)
+    sys.exit(1 if has_error else 0)

lint/requirements.txt

@@ -0,0 +1,2 @@
+yamllint
+pyyaml

ru/elixir.md

@@ -3,7 +3,7 @@ contributors:
     - ["Joao Marques", "http://github.com/mrshankly"]
     - ["Dzianis Dashkevich", "https://github.com/dskecse"]
     - ["Ryan Plant", "https://github.com/ryanplant-au"]
-translator:
+translators:
     - ["Ev Bogdanov", "https://github.com/evbogdanov"]
 filename: learnelixir-ru.ex
 ---

tests/encoding.rb

@@ -1,32 +0,0 @@
-#!/usr/bin/env ruby
-require 'charlock_holmes'
-$file_count = 0;
-markdown_files = Dir["./**/*.html.markdown"]
-markdown_files.each do |file|
-  begin
-    contents = File.read(file)
-    detection = CharlockHolmes::EncodingDetector.detect(contents)
-    case detection[:encoding]
-    when 'UTF-8'
-      $file_count = $file_count + 1
-    when 'ISO-8859-1'
-      $file_count = $file_count + 1
-    when /ISO-8859/
-      puts "Notice: #{file} was detected as #{detection[:encoding]} encoding. Everything is probably fine."
-      $file_count = $file_count + 1
-    else
-      puts "WARNING #{file} was detected as #{detection[:encoding]} encoding. Please save the file in UTF-8!"
-    end
-  rescue Exception => msg
-    puts msg
-  end
-end
-files_failed = markdown_files.length - $file_count
-if files_failed != 0
-  puts "FAILURE!!! #{files_failed} files were unable to be validated as UTF-8!"
-  puts "Please resave the file as UTF-8."
-  exit 1
-else
-  puts "Success. All #{$file_count} files passed UTF-8 validity checks."
-  exit 0
-end

tests/yaml.rb

@@ -1,21 +0,0 @@
-#!/usr/bin/env ruby
-require 'yaml';
-$file_count = 0;
-markdown_files = Dir["./**/*.html.markdown"]
-markdown_files.each do |file|
-  begin
-    YAML.load_file(file)
-    $file_count = $file_count + 1
-  rescue Exception => msg
-    puts msg
-  end
-end
-files_failed = markdown_files.length - $file_count
-if files_failed != 0
-  puts "FAILURE!!! #{files_failed} files were unable to be parsed!"
-  puts "Please check the YAML headers for the documents that failed!"
-  exit 1
-else
-  puts "All #{$file_count} files were verified valid YAML"
-  exit 0
-end

tr/git.md

@@ -8,7 +8,6 @@ contributors:
     - ["Jason Stathopulos", "http://github.com/SpiritBreaker226"]
     - ["Milo Gilad", "http://github.com/Myl0g"]
     - ["Adem Budak", "https://github.com/p1v0t"]
-    
 filename: LearnGit-tr.txt
 ---
 

vim9script.md

@@ -0,0 +1,443 @@
+---
+name: Vim9script
+filename: learn9vimscript.vim
+contributors:
+    - ["HiPhish", "http://hiphish.github.io/"]
+---
+
+```vim
+# ##############
+#  Introduction
+# ##############
+
+# Vim9 script is a modernized version of Vim's scripting language, offering features like variables, functions, and loops.
+# Accoding to `:help vim9-differences`, the principal differences from legacy Vim script are as follows:
+# 
+# - Comments start with #, not ": >
+# 	echo "hello"   # comment
+# - Using a backslash for line continuation is hardly ever needed: >
+# 	echo "hello "
+# 	     .. yourName
+# 	     .. ", how are you?"
+# - White space is required in many places to improve readability.
+# - Assign values without `:let` *E1126* , declare variables with `:var`: >
+# 	var count = 0
+# 	count += 3
+# - Constants can be declared with `:final` and `:const`: >
+# 	final matches = []		  # add to the list later
+# 	const names = ['Betty', 'Peter']  # cannot be changed
+# - `:final` cannot be used as an abbreviation of `:finally`.
+# - Variables and functions are script-local by default.
+# - Functions are declared with argument types and return type: >
+# 	def CallMe(count: number, message: string): bool
+# - Call functions without `:call`: >
+# 	writefile(['done'], 'file.txt')
+# - You cannot use old Ex commands:
+# 	`:Print`
+# 	`:append`
+# 	`:change`
+# 	`:d`  directly followed by 'd' or 'p'.
+# 	`:insert`
+# 	`:k`
+# 	`:mode`
+# 	`:open`
+# 	`:s`  with only flags
+# 	`:t`
+# 	`:xit`
+# - Some commands, especially those used for flow control, cannot be shortened.
+#   E.g., `:throw` cannot be written as `:th`.  *vim9-no-shorten*
+# - You cannot use curly-braces names.
+# - A range before a command must be prefixed with a colon: >
+# 	:%s/this/that
+# - Executing a register with "@r" does not work, you can prepend a colon or use
+#   `:exe`: >
+# 	:exe @a
+# - Unless mentioned specifically, the highest |scriptversion| is used.
+# - When defining an expression mapping, the expression will be evaluated in the
+#   context of the script where it was defined.
+# - When indexing a string the index is counted in characters, not bytes:
+#   |vim9-string-index|
+# - Some possibly unexpected differences: |vim9-gotchas|.
+#
+# You can run Vim9 script commands in command-line mode or write them to a file and source it in Vim.
+# This guide assumes familiarity with ex-commands and focuses on scripting.
+
+# Comments start with #
+# The vertical line '|' separates commands
+echo 'Hello' | echo 'world!'
+
+# Putting a comment after a command usually works
+pwd  # Displays the current working directory
+
+# Line continuation is rarely needed
+echo "Hello "
+     .. "world"
+
+echo [1, 2]
+
+echo {
+    'a': 1,
+    'b': 2
+}
+
+# #######
+#  Types
+# #######
+
+# Numbers
+echo 123         # Decimal
+echo 0b1111011   # Binary
+echo 0173        # Octal
+echo 0x7B        # Hexadecimal
+echo 123.0       # Floating-point
+echo 1.23e2      # Floating-point (scientific notation)
+
+# Booleans
+echo true      # Evaluates to true
+echo false     # Evaluates to false
+
+# Boolean values from comparison
+echo x == y      # Equality by value
+echo x != y      # Inequality
+echo x > y       # Greater than
+echo x >= y      # Greater than or equal
+echo x < y       # Smaller than
+echo x <= y      # Smaller than or equal
+echo x is y      # Instance identity
+echo x isnot y   # Instance non-identity
+
+# Strings
+echo 'a' < 'B'   # True or false depending on 'ignorecase'
+echo 'a' <? 'B'  # True
+echo 'a' <# 'B'  # False
+
+# Regular expression matching
+echo "hi" =~ "hello"    # Regular expression match
+echo "hi" =~# "hello"   # Case sensitive
+echo "hi" =~? "hello"   # Case insensitive
+echo "hi" !~ "hello"    # Regular expression unmatch
+echo "hi" !~# "hello"   # Case sensitive
+echo "hi" !~? "hello"   # Case insensitive
+
+# Boolean operations
+echo true && false  # Logical AND
+echo true || false  # Logical OR
+echo !true            # Logical NOT
+echo true ? 'yes' : 'no'  # Ternary operator
+
+# Strings
+echo "Hello world\n"   # Newline
+echo 'Hello world\n'   # Literal
+echo 'Let''s go!'      # Two single quotes become one
+
+# String concatenation
+echo 'Hello ' .. 'world'  # String concatenation
+
+# String indexing
+echo 'Hello'[0]           # First character
+echo 'Hello'[1]           # Second character
+echo 'Hellö'[4]           # Returns a character
+
+# Substrings
+echo 'Hello'[:]           # Copy of entire string
+echo 'Hello'[1:3]         # Substring
+echo 'Hello'[1:-2]        # Substring until second to last character
+echo 'Hello'[1:]          # Substring with starting index
+echo 'Hello'[:2]          # Substring with ending index
+echo 'Hello'[-2:]         # Substring relative to end
+
+# Lists
+echo []                   # Empty list
+echo [1, 2, 'Hello']      # List with elements
+echo [1, 2, 'Hello', ]    # Trailing comma permitted
+echo [[1, 2], 'Hello']    # Nested lists
+
+# List concatenation
+echo [1, 2] + [3, 4]      # Creates a new list
+
+# List indexing
+echo [1, 2, 3, 4][2]      # Third element
+echo [1, 2, 3, 4][-1]     # Last element
+
+# List slicing
+echo [1, 2, 3, 4][:]      # Shallow copy
+echo [1, 2, 3, 4][:2]     # Sublist until third item
+echo [1, 2, 3, 4][2:]     # Sublist from third item
+echo [1, 2, 3, 4][:-2]    # Sublist until second-to-last item
+
+# Dictionaries
+echo {}                       # Empty dictionary
+echo {'a': 1, 'b': 2}         # Dictionary literal
+echo {'a': 1, 'b': 2, }       # Trailing comma permitted
+echo {'x': {'a': 1, 'b': 2}}  # Nested dictionary
+
+# Indexing a dictionary
+echo {'a': 1, 'b': 2}['a']    # Literal index
+echo {'a': 1, 'b': 2}.a       # Syntactic sugar
+
+# Funcref
+echo function('type')         # Reference to function type()
+echo {x -> x * x}             # Anonymous function
+
+# Regular expression
+substitute/hello/Hello/
+
+# ###########################
+#  Implicit type conversions
+# ###########################
+
+echo "1" + 1         # Number
+echo "1" .. 1        # String
+echo "0xA" + 1       # Number
+
+# ###########
+#  Variables
+# ###########
+
+var b:my_var = 1        # Local to current buffer
+var w:my_var = 1        # Local to current window
+var t:my_var = 1        # Local to current tab page
+var g:my_var = 1        # Global variable
+
+# Access special Vim memory like variables
+var @a = 'Hello'        # Register
+var $PATH=''            # Environment variable
+var &textwidth = 79     # Option
+var &l:textwidth = 79   # Local option
+var &g:textwidth = 79   # Global option
+
+# Access scopes as dictionaries
+echo b:                # All buffer variables
+echo w:                # All window variables
+echo t:                # All tab page variables
+echo g:                # All global variables
+echo v:                # All Vim variables
+
+# Constant variables
+const x = 10            # Constant
+
+# Function reference variables
+var IsString = {x -> type(x) == type('')}    # Global
+var isNumber = {x -> type(x) == type(0)}   # Local
+
+# Multiple value binding
+var [x, y] = [1, 2]
+
+# Assign the remainder to a rest variable
+var [mother, father; children] = ['Alice', 'Bob', 'Carol', 'Dennis', 'Emily']
+
+# ##############
+#  Flow control
+# ##############
+
+# Conditional
+var condition = true
+
+if condition
+    echo 'First condition'
+elseif another_condition
+    echo 'Second condition'
+else
+    echo 'Fail'
+endif
+
+# Loops
+
+# For-loop
+for person in ['Alice', 'Bob', 'Carol', 'Dennis', 'Emily']
+    echo 'Hello ' .. person
+endfor
+
+# Iterate over a nested list
+for [x, y] in [[1, 0], [0, 1], [-1, 0], [0, -1]]
+    echo 'Position: x =' .. x .. ', y = ' .. y
+endfor
+
+# Iterate over a range of numbers
+for i in range(10, 0, -1)
+    echo 'T minus' .. i
+endfor
+
+# Iterate over the keys of a dictionary
+for symbol in keys({'π': 3.14, 'e': 2.71})
+    echo 'The constant ' .. symbol .. ' is a transcendent number'
+endfor
+
+# Iterate over the values of a dictionary
+for value in values({'π': 3.14, 'e': 2.71})
+    echo 'The value ' .. value .. ' approximates a transcendent number'
+endfor
+
+# Iterate over the keys and values of a dictionary
+for [symbol, value] in items({'π': 3.14, 'e': 2.71})
+    echo 'The number ' .. symbol .. ' is approximately ' .. value
+endfor
+
+# While-loops
+var there_yet = true
+while !there_yet
+    echo 'Are we there yet?'
+endwhile
+
+# Exception handling
+try
+    source path/to/file
+catch /Cannot open/
+    echo 'Looks like that file does not exist'
+catch /.*/
+    echo 'Something went wrong, but I do not know what'
+finally
+    echo 'I am done trying'
+endtry
+
+# ##########
+#  Functions
+# ##########
+
+# Defining functions
+def AddNumbersLoudly(x: number, y: number): number
+    echo 'Adding' .. x .. 'and' .. y
+    return x + y
+enddef
+
+def s:addNumbersLoudly(x: number, y: number): number
+    echo 'Adding' .. x .. 'and' .. y
+    return x + y
+enddef
+
+# Range functions
+def FirstAndLastLine() range
+    echo [a:firstline, a:lastline]
+enddef
+
+# Aborting functions
+def SourceMyFile() abort
+    source my-file.vim
+    echo 'This will never be printed'
+enddef
+
+# Closures
+def MakeAdder(x: number)
+    def Adder(n: number) closure
+        return n + x
+    enddef
+    return funcref('Adder')
+enddef
+var AddFive = MakeAdder(5)
+echo AddFive(3)  # Prints 8
+
+# Dictionary functions
+def Mylen() dict
+    return len(self.data)
+enddef
+var mydict = {'data': [0, 1, 2, 3], 'len': function("Mylen")}
+echo mydict.len()
+
+# Alternatively, more concise
+var mydict = {'data': [0, 1, 2, 3]}
+def mydict.len()
+    return len(self.data)
+enddef
+
+# Calling functions
+var animals = keys({'cow': 'moo', 'dog': 'woof', 'cat': 'meow'})
+
+# Call a function for its side effects only
+call sign_undefine()
+
+# The call() function
+echo call(function('get'), [{'a': 1, 'b': 2}, 'c', 3])  # Prints 3
+
+# Function namespaces
+def foo#bar#log(value: string)
+    echomsg value
+enddef
+
+call foo#bar#log('Hello')
+
+# #############################
+#  Frequently used ex-commands
+# #############################
+
+# Sourcing runtime files
+runtime plugin/my-plugin.vim
+
+# Defining new ex-commands
+command! SwapAdjacentLines normal! ddp
+
+command! -nargs=1 Error echoerr <args>
+
+# Defining auto-commands
+autocmd BufWritePost $MYVIMRC source $MYVIMRC
+
+# Auto groups
+augroup auto-source
+    autocmd!
+    autocmd BufWritePost $MYVIMRC source $MYVIMRC
+augroup END
+
+# Executing
+var line = 3
+execute line .. 'delete'
+
+# Executing normal-mode commands
+normal! ggddGp
+
+# Window commands
+wincmd L
+
+# ###########################
+#  Frequently used functions
+# ###########################
+
+# Feature check
+echo has('nvim')
+echo has('python3')
+echo has('unix')
+echo has('win32')
+
+# Test if something exists
+echo exists('&mouse')
+echo exists('+mouse')
+echo exists('$HOSTNAME')
+echo exists('*strftime')
+echo exists('**s:MyFunc')
+echo exists('bufcount')
+echo exists('my_dict["foo"]')
+echo exists(':Make')
+echo exists("#CursorHold")
+echo exists("#BufReadPre#*.gz")
+echo exists("#filetypeindent")
+echo exists("##ColorScheme")
+
+# Various dynamic values
+echo expand('%')
+echo expand('<cword>')
+echo expand('%:p')
+
+# Type tests
+echo type(my_var) == v:t_number
+echo type(my_var) == v:t_string
+echo type(my_var) == v:t_func
+echo type(my_var) == v:t_list
+echo type(my_var) == v:t_dict
+echo type(my_var) == v:t_float
+echo type(my_var) == v:t_bool
+echo my_var is v:null
+
+# Format strings
+echo printf('%d in hexadecimal is %X', 123, 123)
+
+# #####################
+#  Tricks of the trade
+# #####################
+
+# Source guard
+if exists('g:loaded_my_plugin')
+    finish
+endif
+var g_loaded_my_plugin = true
+
+# Default values
+var greeting = get(g:, 'my_plugin_greeting', 'Hello')
+```

zh-cn/qt.md

@@ -4,7 +4,6 @@ contributors:
     - ["Aleksey Kholovchuk", "https://github.com/vortexxx192"]
 translators:
     - ["GengchenXU", "https://github.com/GengchenXU"]
-    
 ---
 
 **Qt** Qt是一个广为人知的框架，用于开发跨平台软件，该软件可以在各种软件和硬件平台上运行，代码几乎没有变化，同时具有本机应用程序的能力和速度。虽然**Qt**最初是用*C*++，但也有其他语言的端口: *[PyQt](../pyqt/)*, *QtRuby*, *PHP-Qt*, 等等.