9

Most nonprinting characters in your input are also illegal, except in character constants and character strings. Except for the tab and formfeed characters, which are used to format the program, nonprinting characters in the input file print as the character ? in your listing.

String Errors

Encountering an end-of-line after an opening string quotation mark (') without first encountering the matching closing quote yields the diagnostic:

Unmatched ' for string.

Also, anything enclosed in double quotes (for example, "hello") is treated as a comment and is, therefore, ignored.

Programs containing # characters (other than in column 1 or in arbitrary-based integers) can produce this diagnostic, because early implementations of Pascal use # as a string delimiter. In this version, # is used for #include and preprocessor directives, and must be in column 1.

Digits in Real Numbers

Pascal requires digits in real statements b := .075; and diagnostics in Pascal:

numbers before the decimal point. Thus, the c := 05e-10;generate the following

Mon Feb 13 10:46:44 1995 digerr.p:

5

b:= .075;

 

e 18740-------------------

^---

Digits required before decimal

point

 

 

6

c:= .05e-10

 

e 18740-------------------

^---

Digits required before decimal

point

 

 

These constructs are also illegal as data input to variables in read statements whose arguments are variables of type real, single, shortreal, double,

and longreal.

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Pascal 4.0 User’s Guide