Modelica.Utilities.Strings.Advanced

Advanced scanning functions

Information

Library content

Package Strings.Advanced contains basic scanning functions. These functions should be not called directly, because it is much simpler to utilize the higher level functions "Strings.scanXXX". The functions of the "Strings.Advanced" library provide the basic interface in order to implement the higher level functions in package "Strings".

Library "Advanced" provides the following functions:

(nextIndex, realNumber)    = scanReal        (string, startIndex, unsigned=false);
(nextIndex, integerNumber) = scanInteger     (string, startIndex, unsigned=false);
(nextIndex, string2)       = scanString      (string, startIndex);
(nextIndex, identifier)    = scanIdentifier  (string, startIndex);
 nextIndex                 = skipWhiteSpace  (string, startIndex);
 nextIndex                 = skipLineComments(string, startIndex);

All functions perform the following actions:

1. Scanning starts at character position "startIndex" of "string" (startIndex has a default of 1).
2. First, white space is skipped, such as blanks (" "), tabs ("\t"), or newline ("\n")
3. Afterwards, the required token is scanned.
4. If successful, on return nextIndex = index of character directly after the found token and the token value is returned as second output argument.
   If not successful, on return nextIndex = startIndex.

The following additional rules apply for the scanning:

• Function scanReal:
  Scans a full number including one optional leading "+" or "-" (if unsigned=false) according to the Modelica grammar. For example, "+1.23e-5", "0.123" are Real numbers, but ".1" is not. Note, an Integer number, such as "123" is also treated as a Real number.
   
• Function scanInteger:
  Scans an Integer number including one optional leading "+" or "-" (if unsigned=false) according to the Modelica (and C/C++) grammar. For example, "+123", "20" are Integer numbers. Note, a Real number, such as "123.4" is not an Integer and scanInteger returns nextIndex = startIndex.
   
• Function scanString:
  Scans a String according to the Modelica (and C/C++) grammar, e.g., "This is a "string"" is a valid string token.
   
• Function scanIdentifier:
  Scans a Modelica identifier, i.e., the identifier starts either with a letter, followed by letters, digits or "_". For example, "w_rel", "T12".
   
• Function skipLineComments
  Skips white space and Modelica (C/C++) line comments iteratively. A line comment starts with "//" and ends either with an end-of-line ("\n") or the end of the "string".

Extends from Modelica.Icons.FunctionsPackage (Icon for packages containing functions).

Package Content

Name	Description
scanReal	Scan a signed real number
scanInteger	Scan signed integer number
scanString	Scan string
scanIdentifier	Scan simple identifiers
skipWhiteSpace	Scan white space
skipLineComments	Scan comments and white space

Modelica.Utilities.Strings.Advanced.scanReal

Scan a signed real number

Information

Syntax

(nextIndex, realNumber) = scanReal(string, startIndex=1, unsigned=false);

Description

Starts scanning of "string" at position "startIndex". First skips white space and scans afterwards a number of type Real with an optional sign according to the Modelica grammar:

real     ::= [sign] unsigned [fraction] [exponent]
sign     ::= '+' | '-'
unsigned ::= digit [unsigned]
fraction ::= '.' [unsigned]
exponent ::= ('e' | 'E') [sign] unsigned
digit    ::= '0'|'1'|'2'|'3'|'4'|'5'|'6'|'7'|'8'|'9'

If successful, the function returns nextIndex = index of character directly after the found real number, as well as the value in the second output argument.

If not successful, on return nextIndex = startIndex and the second output argument is zero.

If the optional argument "unsigned" is true, the number shall not start with '+' or '-'. The default of "unsigned" is false.

See also

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

Outputs

Modelica.Utilities.Strings.Advanced.scanInteger

Scan signed integer number

Information

Syntax

(nextIndex, integerNumber) = scanInteger(string, startIndex=1, unsigned=false);

Description

Starts scanning of "string" at position "startIndex". First skips white space and scans afterwards a signed number of type Integer. An Integer starts with an optional '+' or '-', immediately followed by a non-empty sequence of digits.

If successful, the function returns nextIndex = index of character directly after the found Integer number, as well as the Integer value in the second output argument.

If not successful, on return nextIndex = startIndex and the second output argument is zero.

Note, a Real number, such as "123.4", is not treated as an Integer number and scanInteger will return nextIndex = startIndex in this case.

If the optional argument "unsigned" is true, the number shall not start with '+' or '-'. The default of "unsigned" is false.

See also

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

Outputs

Modelica.Utilities.Strings.Advanced.scanString

Scan string

Information

Syntax

(nextIndex, string2) = scanString(string, startIndex=1);

Description

Starts scanning of "string" at position "startIndex". First skips white space and scans afterwards a string according to the Modelica grammar, i.e., a string enclosed in double quotes.

If successful, the function returns nextIndex = index of character directly after the found string, as well as the string value in the second output argument.

If not successful, on return nextIndex = startIndex and the second output argument is an empty string.

See also

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

Outputs

Modelica.Utilities.Strings.Advanced.scanIdentifier

Scan simple identifiers

Information

Syntax

(nextIndex, identifier) = scanIdentifier(string, startIndex=1);

Description

Starts scanning of "string" at position "startIndex". First skips white space and scans afterwards a Modelica identifier, i.e., a sequence of characters starting with a letter ("a".."z" or "A".."Z") followed by letters, digits or underscores ("_").

If successful, the function returns nextIndex = index of character directly after the found identifier, as well as the identifier as string in the second output argument.

If not successful, on return nextIndex = startIndex and the second output argument is an empty string.

See also

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

Outputs

Modelica.Utilities.Strings.Advanced.skipWhiteSpace

Scan white space

Information

Syntax

nextIndex = skipWhiteSpace(string, startIndex);

Description

Starts scanning of "string" at position "startIndex" and skips white space. The function returns nextIndex = index of character of the first non white space character.

See also

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

Outputs

Modelica.Utilities.Strings.Advanced.skipLineComments

Scan comments and white space

Information

Syntax

nextIndex = skipLineComments(string, startIndex);

Description

Starts scanning of "string" at position "startIndex". First skips white space and scans afterwards a Modelica (C/C++) line comment, i.e., a sequence of characters that starts with "//" and ends with an end-of-line "\n" or with the end of the string. If end-of-line is reached, the function continues to skip white space and scanning of line comments until end-of-string is reached, or another token is detected.

If successful, the function returns nextIndex = index of character directly after the found line comment.

If not successful, on return nextIndex = startIndex.

See also

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

Outputs