library(readin)

read_in(-Sentence)

reads characters from the current input stream until it finds end-of-file or a sentence terminator (see is_period/1) at the end of a line. There may be any number of tabs and spaces between that stop and the end of the line. It then breaks the characters up into "words", where a "word" is

• a sequence of letters (see is_alpha/1), which is converted to lowercase and returned as a Prolog atom
• a sequence of decimal digits (see is_digit/1), which is returned as a Prolog integer (plus and minus signs become separate atoms).
• any graphic character other than a letter or digit, which is returned as a single-character Prolog atom

The resulting list is returned in Sentence. The punctuation mark that terminated the sentence is included in the list. Here is an example:

          | ?- read_in(X).
          |: This is an example.  An example of read-in.  In
          |: it there are +00003 sentences!
          
          X = [this,is,an,example,.,an,example,of,read,-,
               in,.,in,it,there,are,+,3,sentences,!]
          

Note that the end-of-line character, and any spaces and tabs following the sentence terminator, are consumed. It is important that the end-of-line character be consumed; otherwise subsequent prompts will behave unpredictably.