Modelica.Utilities.Strings.Advanced

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".

Package Content

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

Modelica.Utilities.Strings.Advanced.scanReal

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 a function).

Inputs

Type	Name	Default	Description
String	string
Integer	startIndex	1	Index where scanning starts
Boolean	unsigned	false	= true, if number shall not start with '+' or '-'

Outputs

Type	Name	Description
Integer	nextIndex	Index after the found token (success=true) or index at which scanning failed (success=false)
Real	number	Value of Real number

Modelica definition

function scanReal "Scans a signed real number"
  extends Modelica.Icons.Function;
  input String string;
  input Integer startIndex(min=1)=1 "Index where scanning starts";
  input Boolean unsigned=false 
    "= true, if number shall not start with '+' or '-'";
  output Integer nextIndex 
    "Index after the found token (success=true) or index at which scanning failed (success=false)";
  output Real number "Value of Real number";
  external "C" ModelicaStrings_scanReal(string, startIndex, unsigned, nextIndex, number);
end scanReal;

Modelica.Utilities.Strings.Advanced.scanInteger

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 a function).

Inputs

Type	Name	Default	Description
String	string
Integer	startIndex	1
Boolean	unsigned	false	= true, if number shall not start with '+' or '-'

Outputs

Type	Name	Description
Integer	nextIndex	Index after the found token (success=true) or index at which scanning failed (success=false)
Integer	number	Value of Integer number

Modelica definition

function scanInteger "Scans signed integer number"
  extends Modelica.Icons.Function;
  input String string;
  input Integer startIndex(min=1)=1;
  input Boolean unsigned=false 
    "= true, if number shall not start with '+' or '-'";
  output Integer nextIndex 
    "Index after the found token (success=true) or index at which scanning failed (success=false)";
  output Integer number "Value of Integer number";
  external "C" ModelicaStrings_scanInteger(string, startIndex, unsigned, nextIndex, number);
end scanInteger;

Modelica.Utilities.Strings.Advanced.scanString

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 a function).

Inputs

Type	Name	Default	Description
String	string
Integer	startIndex	1	Index where scanning starts

Outputs

Type	Name	Description
Integer	nextIndex	Index after the found token (success=true) or index at which scanning failed (success=false)
String	string2	Value of String token

Modelica definition

function scanString "Scan string"
  extends Modelica.Icons.Function;
  input String string;
  input Integer startIndex(min=1)=1 "Index where scanning starts";
  output Integer nextIndex 
    "Index after the found token (success=true) or index at which scanning failed (success=false)";
  output String string2 "Value of String token";
  external "C" ModelicaStrings_scanString(string, startIndex, nextIndex, string2);
end scanString;

Modelica.Utilities.Strings.Advanced.scanIdentifier

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 a function).

Inputs

Type	Name	Default	Description
String	string
Integer	startIndex	1	Index where scanning starts

Outputs

Type	Name	Description
Integer	nextIndex	Index after the found token (success=true) or index at which scanning failed (success=false)
String	identifier	Value of identifier token

Modelica definition

function scanIdentifier "Scans simple identifiers"
  extends Modelica.Icons.Function;
  input String string;
  input Integer startIndex(min=1)=1 "Index where scanning starts";
  output Integer nextIndex 
    "Index after the found token (success=true) or index at which scanning failed (success=false)";
  output String identifier "Value of identifier token";
  external "C" ModelicaStrings_scanIdentifier(string, startIndex, nextIndex, identifier);

end scanIdentifier;

Modelica.Utilities.Strings.Advanced.skipWhiteSpace

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 a function).

Inputs

Type	Name	Default	Description
String	string
Integer	startIndex	1

Outputs

Type	Name	Description
Integer	nextIndex

Modelica definition

function skipWhiteSpace "Scans white space"
  extends Modelica.Icons.Function;
  input String string;
  input Integer startIndex(min=1)=1;
  output Integer nextIndex;
  external "C" nextIndex = ModelicaStrings_skipWhiteSpace(string, startIndex);
end skipWhiteSpace;

Modelica.Utilities.Strings.Advanced.skipLineComments

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 a function).

Inputs

Type	Name	Default	Description
String	string
Integer	startIndex	1

Outputs

Type	Name	Description
Integer	nextIndex

Modelica definition

function skipLineComments "Scans comments and white space"
  extends Modelica.Icons.Function;
  input String string;
  input Integer startIndex(min=1)=1;
  output Integer nextIndex;
protected 
  Integer lenString = length(string);
  Boolean scanning;
  Boolean lineComment;
algorithm 
  nextIndex := startIndex;
  scanning := true;
  while scanning loop
     nextIndex := Advanced.skipWhiteSpace(string, nextIndex);
     if nextIndex+1 <= lenString then
        if substring(string,nextIndex,nextIndex+1) == "//" then
           // search end of line comment
           nextIndex := nextIndex + 2;
           if nextIndex <= lenString then
              lineComment := true;
              while lineComment loop
                 if substring(string,nextIndex,nextIndex) == "\n" then
                    lineComment := false;
                 end if;
                 nextIndex := nextIndex + 1;
                 if nextIndex > lenString then
                    lineComment := false;
                    scanning := false;
                 end if;
              end while;
           else
              scanning := false;
           end if;
        else
           scanning := false;
        end if;
     else
        scanning := false;
     end if;
  end while;
end skipLineComments;