langur

Langur is an open-source programming language that natively uses decimal floating point, and easily deals with extremely large or small numbers. Its principles of design are accuracy in calculation and a clear, expressive syntax.

The following is a partial list of features.

decimal floating point for numbers, (arbitrary precision)
dynamic type system
automatic memory management
highly expressive switch expressions
first-order functions, including closures
flexible parameter options, such as argument/parameter expansion, parameters by name, and required or optional parameters
semi-integrated regex
ISO 8601 date/time literals
duration literals
integer basex notation (for base 2 to 36), such as 2x1010_0010 or -11x123A
automated for loop over a list, hash, or string, or using a range
chained string interpolation modifiers
catching exceptions without explicit try blocks
both truncating and floor division operators; also remainder and modulus, exponent and root
optional “database” operators (null propagating)

Influences include at least the following languages.

Go, Python, C, Perl, and Monkey

books

I initially developed langur following very useful books by Thorsten Ball (Writing an Interpreter in Go, Writing a Compiler in Go), but it has changed dramatically since.

I wrote a small book that does not compare to Mr. Ball's books mentioned above. It explains the design of some of langur's advanced features, in its stack-based virtual machine. See a free preview chapter at opcodebook.com.