Show all current vim variables
:let
:put L2 | put L1
Create local variables
:let s:local_var = 42
b:name variable local to a buffer
w:name variable local to a window
g:name global variable (also in a function)
v:name variable predefined by Vim
Delete variables
:unlet global_var
:unlet s:local_var
Check if a var name exists already
if exists("var_name")
echo "variable name already in use"
endif
if !exists("var_name")
echo "Usable variable name"
endif
In vim, zero is false. Anything else is True
[Caution!], vim will convert any string without digit ahead to zero
Thus,:if "true"will be considered as:if false
meanwhile:if "1true"is true, and:if "0true"still false.
Special Escape Characters
\e <Esc>
\<Esc> <Esc>
\<C-W> CTRL-W
The last two are just examples. The
"\<name>"form can be used to include the special key "name".
Vim expressions
$NAME environment variable
&name option
@r register
Examples:
:echo "The value of 'tabstop' is" &ts
:echo "Your home directory is" $HOME
:echo @a == 0
Concatenate Strings
In vim script, you use . to join strings
echo "I am" . " your daddy."
Conditional Expression
Example: a ? b : c, If "a" evaluated to true, "b" is used, otherwise "c" is used.
Value Comparison
As we have mentioned, strings starts without a number would be consider zero when comparing to a number. Thus:
:echo "string_starts_with_alpha" == 0
1
:echo "!!!&?*Punctuations" == 0
1
:echo "End_with_number369" == 0
1
:echo "42startswith_number" == 0
0
:echo "42startswith_number" == 42
1
When comparing strings, ignore option is used, you can specify ==# to match case, and ==? to ignore case.
# VIEW VALUE OF IGNORECASE OPTION
:echo &ignorecase
0
:echo &ic
0
# COMPARISON EXAMPLES
:echo "PApa" ==? "paPa"
1
:echo "JORDAN" ==# "jorDAn"
0
Besides of comparing equal, you can compare if a string match with a pattern,
by using s =~ p and s !~ p, where s is a string, and p a pattern
:echo "nimabi" =~ 'n*m*b'
1
echo "nimabi" =~ 'nmb'
0
echo "nimabi" !~ 'nmb'
1
if str !~ '\.$'
echo "string doesn't end with period"
endif
Be aware that when pattern wrapped in
single quotes, you only needone slashto escape special characters.
If you wrapped pattern intwo single quotes, you'll needtwo slashto escape a special character.
EXEC function in vim script
:let str1 = "r"
:let str2 = "!date"
:execute str1 . str2
To exectue normal mode command, we use normal as the initial command
# Be aware you can't copy this command in OSX directly
# You need to type by pressing CTRL-V, then <Esc>
:normal Insert and clone yyp
# Another way to excute a normal mode command is using execute with strings,
# in this way, the command is copiable
:execute "normal iInsert and clone \<Esc> yyp"
EVAL Function in vim script
let p = eval('&path')
echo p
.,/usr/include,,
Functions
A few usages of functions in vim:
:let line = getline(".")
:let replaced_line = substitute(line, '\a', "*", "g")
:call setline(".", replaced_line)
# RESULT
:*** **** = *******(".")
.means the position of the cursor
Define your own functions
Function name must begin with a capital letter, bare return returns 0.
Variables inside a function is a local function.
You can speicified a local variable with prepending l:, or it may clash with vim reserve variables.
Such as when typing count in a function, you are refers to v:count.
To define variables of other scopes, you prepend it with g:, a: or s:.g: is global variable, a: is argument variable and s: is script variable.
To redefine an exists function you use add ! to :function, which is :function!.
Function with range:
function AddShellPrompt() range
let lnum = a:firstline
while lnum <= a:lastline
let replaced_line = substitute(getline(lnum), '^\s\+', '&>>>', '')
call setline(lnum, replaced_line)
let lnum += 1
endwhile
endfunction
# By using `:1,-1 call AddShellPrompt()
# You can add >>> for all your code examples in a markdown file
Function without range:
function PrintLine()
echo getline(".")
endfunction
# By using `:1,20 call PrintLine()
# You will get line1 to line20 printed on your screen.
# Meanwhile cursor moved to line20
Function with undefinite numbers of variables:
In vim, you can specify that a function need particular numbers of concret variables,
and undefinite numbers of possible variables(max optional var num is 20).
Let's see an example:
function EchoVars(v1, v2, ...)
echo a:v1
echo a:v2
echo a:0
echo a:1
echo a:2
echo a:000
endfunction
"# CALL IT
call EchoVars('a','b','c','d','e', 'f', 'g')
"# RESULT
a
b
5
c
d
['c', 'd', 'e', 'f', 'g']
From the example above, we can see a:0 refers to the total num of optional vars,a:000 is the list of all optional vars, meanwhile a:1 is the first optioanl var, and so on.
There is a way to assign a reference to a function by using function(). Here is an example:
:function Titan()
: echo "Shivering under the power of reference, insects!"
:endfunction
:let Ref1 = function('Titan')
:call Ref1()
Shivering under the power of reference, insects!
You use function to view all user-defined functions, type function FunctionName to view code of a particular function.
And :delfunction FunctionName can help you delete a function.
CLASSES
Vim script doesn't have class structure. But you can "Leverage" a dict to make it a rudimental class.
And you use copy() function to make instances of it.
:let ClassZ = {'author': "Juchen.Zeng"}
:function ClassZ.Print_author_name()
: echo self.author
:endfunction
:function ClassZ.Change_author_name(arg1)
: let self.author = a:arg1
:endfunction
:call ClassZ.Print_author_name()
Juchen.Zeng
:call ClassZ.Change_author_name('MarioLuisGarcia')
:call ClassZ.Print_author_name()
MarioLuisGarcia
:put = string(ClassZ)
{'Change_author_name': function('2'), 'author': 'MarioLuisGarcia', 'Print_author_name': function('1')}
"# You can use `function {function_numer} to view a numbered function, e.g.
:function {2}
function 2(arg1) dict
1 let self.author = a:arg1
endfunction
There is another way to define dict methods, by using extra dict argument when defining a function.
:function Tell_joke() dict
: echo "This is funny!"
:endfunction
:call Tell_joke()
E725: Calling dict function without Dictionary: Tell_joke
:let ClassZ['Talk'] = function('Tell_joke')
:call ClassZ.Talk()
This is funny!
DATA TYPES
LIST
Append elements to list
:let vl = []
:call add(vl, 'i1')
:call add(vl, 'i2')
:echo vl
['i1', 'i2']
Extend a list
:let L1 = [1, 2]
:let L2 = [3, 4]
:echo L1 + L2
[1, 2, 3, 4]
:echo L1
[1, 2]
:let L1 += L2
:let L2 = L2 + L1
:put = string(L2)
[3, 4, 1, 2, 3, 4]
:call extend(L2, L2)
[3, 4, 1, 2, 3, 4, 3, 4, 1, 2, 3, 4]
:call add(L1, L1)
:put = string(L1)
[1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [1, 2, 3, 4, [{E724}]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]
:let L3 = [5, 6]
:call add(L2, L3)
[3, 4, 1, 2, 3, 4, 3, 4, 1, 2, 3, 4, [5, 6]]
Iterate over a list
"# Example 1
:let L = [1,2,3,4,5]
:let n = 0
:for i in L
: let n += i
:endfor
:echo n
15
"# Example 2
:for line in getline(10, 60)
: if line =~ "me"
: put = matchstr(line, '[a-z]*me[a-z]*')
: endif
:endfor
"# RESULT(deleted some "name" result)
name
meanwhile
name
environment
name
Syntax
Excpetion Catch
Catch particular exception
:try
: read ~/files_not_exists
:catch /E484:/
: echo "Sorry, the dir was using to store cookies now"
:endtry
Bare exception
:try
: call messi_jugar_baloncesto
:catch
: echo "Esto es increible"
:endtry
Finally syntax
:try
: call murninho_is_brazilian()
:catch /What?/
:finally
: echo "He win the Prime League at least"
:endtry
No matter what happens between
tryandfinally, the command infinallypart will always been executed.
Line continuation
:!vim temp.vim
function Line_continuation_demonstration()
echo "Let's test the line
\ continuation in
\ vim."
endfunction
:source temp.vim
:call Line_continuation_demonstration()
Let's test the line continuation in vim.