VHDL (abbreviation for VHSIC HDL) is the acronym used for Very High-Speed Integrated Circuit Hardware Description Language.
This is a hardware description language (HDL), intended to describe the behavior and/or architecture of a logical electronic “module,” in other words, a combinatorial and/or sequential logic function. Along with Verilog, it is the most widely used language for the design of digital electronic systems.
It is one of the main tools for designing modern integrated circuits, successfully applied in the field of microprocessors (DSP, graphic accelerators), in telecommunications (TV, cellular), automobiles (navigation, stability control systems) and others.
The standard for VHDL was issued in 1987, called IEEE 1076. And in 1993 an updated version comes out. It is used in computer-aided design (CAD) of integrated circuits (for example ASIC) or for configuring FPGAs. It has a syntax similar to that of the Ada language.
Whitespace is an esoteric programming language developed by Edwin Brady and Chris Morris of Durham University, developers of Kaya and Idris programming languages. It was launched on April 1, 2003. The name is a reference to the white space characters. Unlike most programming languages, which ignore or give too little meaning to most white space characters, the Whitespace interpreter ignores any characters that are not in white space. Only spaces, tabs, and line flows make sense.
An effect of this programming language is that a Whitespace software can be easily written in the characters of a space of a program written in another language, except for possibilities in languages that depend on spaces for syntax validity, such as Python, which makes the text to be a polyglot.
The programming language was developed by Edwin Brady and Chris Morris in 2001. Slashdot gave an honest review about this language on April 1, 2003.
The idea of using white space characters as operators for C++ was suggested five years before by Bjarne Stroustrup.
Controls consist of space sequences, tab stops, and line feeds. For example, the tab-space-space space performs the arithmetic addition of the first two elements on the stack.
Data are represented in binary using spaces (0) and tabs (1), followed by a power line; thus, the space-space-space-tab-space-tab-tab-linefeed is binary number 0001011, which is 11 in decimal. All other characters are not considered and can be used for commenting lines out.
The code is written as an instruction modification parameter (IMP) followed by the operation. The table below lists all the IMPs in Whitespace.
IMP Meaning
[Space] Stack handling
[Tab] [Space] Arithmetic
[Tab] [Tab] Access to Heap
[LineFeed] Flow control
[Tab] [LineFeed] I/O
Each IMP is followed by one of several operations defined for this IMP.
Note that when the source code is displayed in some browsers, the horizontal spacing produced by a tab character is not fixed, but depends on its location in the text relative to the next stop of the horizontal tabs. Depending on the software, the tab characters can be replaced with the corresponding variable number of space characters.