Lecture 16 – October 19^th

• Maximum length of snobol filename is 8.
• Maximum length of a variable name is 120
• Only * and END and labels should start/be in column 1
• In a character string, ‘A’ and ‘a’ are distinct
• Conditional assignment operator is a period .
• To obtain data from the keyboard you can just say sentence = input where sentence will then hold the input from the keyboard.

Discussed use of:

SPAN

BREAK

ANY

NOTANY

GOTOs

Here’s Oct19.sno - started in 2:00 class & modified in 3:30 class

LETTERS = "ABCDEFGHIJKLMNOPQRSTUVWXYZ'-"

WORD = SPAN(LETTERS)

*

* produce a suitable pattern in WORD. To match the material

* between words (white space, punctuation, etc.), use thepattern:

*

GAP = BREAK(LETTERS)

'SAMPLE LINE' WORD . OUTPUT

*

'PLUS TEN DEGREES' ' ' WORD . OUTPUT

'PLUS TEN DEGREES' (' ' WORD) . OUTPUT

GAPO = GAP . OUTPUT

WORDO = WORD . OUTPUT

': ONE, TWO, THREE' GAPO WORDO GAPO WORDO

DIGITS = '0123456789'

INTEGER = (ANY('+-') | '') SPAN(DIGITS)

'SET -43 VOLTS' INTEGER . OUTPUT

'SET -43.625 VOLTS' INTEGER . OUTPUT

REAL = INTEGER '.' (SPAN(DIGITS) | '')

'SET -43.625 VOLTS' REAL . OUTPUT

S = '0ZERO,1ONE,2TWO,3THREE,4FOUR,5FIVE,'

S 4 BREAK(',') . OUTPUT

END

First 15 minute exercise

Write code to strip the words out of a sentence. You do not know how many words are in the sentence. You should output each one as you find it.

This is Oct19a.sno

B = 'The BLUE BIRD'

COLOR = ('GOLD' | 'BLUE ') . SHADE

CRITTER = ('FISH' | 'BIRD') . ANIMAL

BOTH = COLOR CRITTER

B BOTH

OUTPUT = SHADE

OUTPUT = ANIMAL

OUTPUT = 'Other tests '

SHADE = 'A'

ANIMAL = 'B'

BOTH = CRITTER COLOR

B BOTH

OUTPUT = SHADE

OUTPUT = ANIMAL

VOWEL = ANY('AEIOU')

DVOWEL = VOWEL VOWEL

NOTVOWEL = NOTANY('AEIOU')

VACUUM = 'VACUUM'

VACUUM VOWEL . OUTPUT = ''

VACUUM VOWEL . OUTPUT

VACUUM DVOWEL . OUTPUT

VACUUM (VOWEL NOTVOWEL) . OUTPUT

END

Arrays in Snobol are indexed only by integers

Unlike Pascal and FORTRAN, Snobol arrays are potentially hetereogenous

No limit to the number of dimensions

In Snobol an array is defined during program execution, rather than at compilation time.

The ARRAY function initializes all array elements to the null string.

Second 15 minute exercise

Write code to strip the words out of a sentence. You do not know how many words are in the sentence, You should declare an array and store each word as you get it in the array. There will not be more than 15 words. Print the contents of the array afterwards.

Homework:

1. Study for exam
2. Search the manual for directions on writing subprograms
3. Do the Snobol program described below:to:

Write code to strip the words out of a sentence. You do not know how many words are in the sentence, You should declare an array and store each word as you get it, in the array. There will not be more than 15 words. Print the contents of the array afterwards.

Then use a subprogram to sort the array in ASCENDING alphabetical order (a..z). Finally, print the sorted array. Note: this is a program! It requires documentation and comments. It should be put in the drop box NOT ZIPPED as yourname6.sno. If your name is longer than 5 characters just use the first 5. Turn in the printout of the source code your input and the output produced when the program is run with your input in a folder. Make another folder just in case Pascal Program 3 isn’t graded by class time on Tuesday which is when this program is due.