Natural is a fourth-generation programming language from Software AG. It is largely used for building databases output in plain text form, for example.
* Hello World in NATURAL WRITE 'Hello World!' ENDIt has the ESCAPE TOP flow control instruction, which is similar to continue in C, C++, Java and several other languages, except that it also works within subroutines to both return from the routine and then continue the calling statement's processing loop.
Like continue, it avoids large amounts of indentation levels when using nested instruction blocks inside any loop.
Example with ESCAPE TOP:
DEFINE DATA LOCAL 1 I (N3) /* 3 digits without decimals END-DEFINE FOR I = 2 TO 100 IF (I / 2 * 2) = I AND I > 2 WRITE 'Number' I 'is divisible by 2' ESCAPE TOP END-IF IF (I / 3 * 3) = I AND I > 3 WRITE 'Number' I 'is divisible by 3' ESCAPE TOP END-IF IF (I / 5 * 5) = I AND I > 5 WRITE 'Number' I 'is divisible by 5' ESCAPE TOP END-IF IF (I / 7 * 7) = I AND I > 7 WRITE 'Number' I 'is divisible by 7' ESCAPE TOP END-IF IF (I / 11 * 11) = I AND I > 11 WRITE 'Number' I 'is divisible by 11' ESCAPE TOP END-IF WRITE 'Number' I 'is prime' END-FOR ENDThe levels of indentation can be automatically adjusted with the STRUCT command in the Natural Editor.
The same example, without ESCAPE TOP:
DEFINE DATA LOCAL 1 I (N3) /* 3 digits without decimals END-DEFINE FOR I = 2 TO 100 IF (I / 2 * 2) = I AND I > 2 WRITE 'Number' I 'is divisible by 2' ELSE IF (I / 3 * 3) = I AND I > 3 WRITE 'Number' I 'is divisible by 3' ELSE IF (I / 5 * 5) = I AND I > 5 WRITE 'Number' I 'is divisible by 5' ELSE IF (I / 7 * 7) = I AND I > 7 WRITE 'Number' I 'is divisible by 7' ELSE IF (I / 11 * 11) = I AND I > 11 WRITE 'Number' I 'is divisible by 11' ELSE WRITE 'Number' I 'is prime' END-IF END-IF END-IF END-IF END-IF END-FOR ENDAnother powerful flow control instruction command is the ESCAPE BOTTOM, which is similar to ESCAPE TOP except that it continues the processing from end of the calling statement's processing loop. Example with ESCAPE BOTTOM:
One trait that sets Natural apart from most other languages is its rich syntax. For example, many languages have a simple switch case statement that can be used to replace nested IF statements pertaining to a single variable; in C-like languages, it is prone to logic errors since it is necessary to BREAK out of the statement programatically. Natural has a much cleaner/richer DECIDE statement which is easier to understand and code. Here is an example:
DECIDE ON FIRST VALUE MARITAL-STATUS VALUE 'M' DESC := 'Married' VALUE 'D' DESC := 'Divorced' VALUE 'W' DESC := 'Widowed' ANY ONCE-MARRIED := TRUE NONE DESC := 'Single' END-DECIDEOther articles related to "natural":
... Natural capital is the extension of the economic notion of capital (manufactured means of production) to goods and services relating to the natural ... Natural capital is thus the stock of natural ecosystems that yields a flow of valuable ecosystem goods or services into the future ... Natural capital may also provide services like recycling wastes or water catchment and erosion control ...
... Petroleum and natural gas are formed by the anaerobic decomposition of remains of organisms including phytoplankton and zooplankton that settled to the ... Some fuels like natural gas, for instance, contain only very low boiling, gaseous components ... Terrestrial plants also form type III kerogen, a source of natural gas ...
32% has been invested in Russia, primarily in the natural resources and construction sector, and 46% in Turkey’s Black Sea neighbours, Bulgaria and ... rising demand for energy resources like natural gas and crude oil ... Share of natural gas decreased from 74% in 1980 to 30% in 1990 and 12% in 2005 ...
... should oppose laws which undermine natural law scientists should further study effective methods of natural birth control doctors should further familiarize themselves with this ... closes with an appeal to observe the natural laws of the Most High God ...
... Ukraine is relatively rich in natural resources, particularly in mineral deposits ... Although oil and natural gas reserves in the country are largely exhausted, it has other important energy sources, such as coal, hydroelectricity and nuclear fuel raw materials ...
Famous quotes containing the word natural:
“I esteem it the happiness of this country that its settlers, whilst they were exploring their granted and natural rights and determining the power of the magistrate, were united by personal affection. Members of a church before whose searching covenant all rank was abolished, they stood in awe of each other, as religious men.”
—Ralph Waldo Emerson (1803–1882)
“There are several natural phenomena which I shall have to have explained to me before I can keep on going as a resident member of the human race. One is the metamorphosis which hats and suits undergo exactly one week after their purchase, whereby they are changed from smart, intensely becoming articles of apparel into something children use when they want to “dress up like daddy.””
—Robert Benchley (1889–1945)
“The natural man has only two primal passions, to get and to beget.”
—Sir William Osler (1849–1919)