$Scalar Sigil (eg variables)

Laurence MorganAbout 2 minOperators And TokensSigils

`$Scalar` Sigil (eg variables)

Expand values as a scalar

Description

The scalar token is used to tell Murex to expand variables and sub-shells as a string (ie one single parameter) irrespective of the data that is stored in the string.

One common use case where Murex's approach is better is with file names. Traditional shells would treat spaces as a new file. Whereas Murex treats spaces as any other printable character character.

Variable Syntax

There are two basic syntaxes. Bare and enclosed.

Bare Syntax

Bare syntax looks like the following:

$scalar

The variable token must be followed with one of the following characters: alpha (a to z, upper and lower case), numeric (0 to 1), underscore (_) and/or a full stop (.).

Enclosed Syntax

Enclosed syntax looks like the following:

$(scalar)

Enclosed syntax supports any unicode characters however the variable name needs to be surrounded by parenthesis. See examples below.

Examples

ASCII variable names

» $example = "foobar"
» out $example
foobar

Unicode variable names

Variable names can be non-ASCII however they have to be surrounded by parenthesis. eg

» $(比如) = "举手之劳就可以使办公室更加环保，比如，使用再生纸。"
» out $(比如)
举手之劳就可以使办公室更加环保，比如，使用再生纸。

Infixing inside text

Sometimes you need to denote the end of a variable and have text follow on:

» $partial_word = "orl"
» out "Hello w$(partial_word)d!"
Hello world!

Variables are tokens

Please note the new line (\n) character. This is not split using $:

» $example = "foo\nbar"

Output as a scalar ($):

» out $example
foo
bar

Output as an array (@):

» out @example
foo bar

Scalar and Array Sub-shells

Scalar:

» out ${ %[Mon..Fri] }
["Mon","Tue","Wed","Thu","Fri"]

Array:

» out @{ %[Mon..Fri] }
Mon Tue Wed Thu Fri

out will take an array and output each element, space delimited. Exactly the same how echo would in Bash.

Variable as a Command

If a variable is used as a commend then Murex will just print the content of that variable.

» $example = "Hello World!"

» $example
Hello World!

Detail

Infixing

Strings and sub-shells can be expanded inside double quotes, brace quotes as well as used as barewords. But they cannot be expanded inside single quotes.

» set example="World!"

» out Hello $example
Hello World!

» out 'Hello $example'
Hello $example

» out "Hello $example"
Hello World!

» out %(Hello $example)
Hello World!

However you cannot expand arrays (@) inside any form of quotation since it wouldn't be clear how that value should be expanded relative to the other values inside the quote. This is why array and object builders (%[] and %{} respectively) support array variables but string builders (%()) do not.

$Scalar Sigil (eg variables)

# $Scalar Sigil (eg variables)

# Description

# Variable Syntax

# Bare Syntax

# Enclosed Syntax

# Examples

# ASCII variable names

# Unicode variable names

# Infixing inside text

# Variables are tokens

# Scalar and Array Sub-shells

# Variable as a Command

# Detail

# Infixing

# See Also