Modelica.Utilities.Strings

Operations on strings

Information

Library content

Package Strings contains functions to manipulate strings.

In the table below an example call to every function is given using the default options.

The functions "compare", "isEqual", "count", "find", "findLast", "replace", "sort" have the optional input argument caseSensitive with default true. If false, the operation is carried out without taking into account whether a character is upper or lower case.

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

Package Content

Name	Description
length	Return length of string
substring	Return a substring defined by start and end index
repeat	Repeat a string n times
compare	Compare two strings lexicographically
isEqual	Determine whether two strings are identical
isEmpty	Return true if a string is empty (has only white space characters)
count	Count the number of non-overlapping occurrences of a string
find	Find first occurrence of a string within another string
findLast	Find last occurrence of a string within another string
replace	Replace non-overlapping occurrences of a string from left to right
sort	Sort vector of strings in alphabetic order
hashString	Create a hash value of a string
scanToken	Scan for the next token and return it
scanReal	Scan for the next Real number and trigger an assert if not present
scanInteger	Scan for the next Integer number and trigger an assert if not present
scanBoolean	Scan for the next Boolean number and trigger an assert if not present
scanString	Scan for the next Modelica string and trigger an assert if not present
scanIdentifier	Scan for the next Identifier and trigger an assert if not present
scanDelimiter	Scan for the next delimiter and trigger an assert if not present
scanNoToken	Scan string and check that it contains no more token
syntaxError	Print an error message, a string and the index at which scanning detected an error
Advanced	Advanced scanning functions

Modelica.Utilities.Strings.length

Return length of string

Information

Syntax

Strings.length(string);

Description

Returns the number of characters of "string".

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

Inputs

Outputs

Modelica.Utilities.Strings.substring

Return a substring defined by start and end index

Information

Syntax

string2 = Strings.substring(string, startIndex, endIndex);

Description

This function returns the substring from position startIndex up to and including position endIndex of "string" .

If index, startIndex, or endIndex are not correct, e.g., if endIndex > length(string), an assert is triggered.

Example

string1 := "This is line 111";
string2 := Strings.substring(string1,9,12); // string2 = "line"

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

Inputs

Outputs

Modelica.Utilities.Strings.repeat

Repeat a string n times

Information

Syntax

string2 = Strings.repeat(n);
string2 = Strings.repeat(n, string=" ");

Description

The first form returns a string consisting of n blanks.

The second form returns a string consisting of n substrings defined by the optional argument "string".

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

Inputs

Outputs

Modelica.Utilities.Strings.compare

Compare two strings lexicographically

Information

Syntax

result = Strings.compare(string1, string2);
result = Strings.compare(string1, string2, caseSensitive=true);

Description

Compares two strings. If the optional argument caseSensitive=false, upper case letters are treated as if they would be lower case letters. The result of the comparison is returned as:

result = Modelica.Utilities.Types.Compare.Less     // string1 < string2
       = Modelica.Utilities.Types.Compare.Equal    // string1 = string2
       = Modelica.Utilities.Types.Compare.Greater  // string1 > string2

Comparison is with regards to lexicographical order, e.g., "a" < "b";

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

Inputs

Outputs

Modelica.Utilities.Strings.isEqual

Determine whether two strings are identical

Information

Syntax

Strings.isEqual(string1, string2);
Strings.isEqual(string1, string2, caseSensitive=true);

Description

Compare whether two strings are identical, optionally ignoring case.

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

Inputs

Outputs

Modelica.Utilities.Strings.isEmpty

Return true if a string is empty (has only white space characters)

Information

Syntax

Strings.isEmpty(string);

Description

Returns true if the string has no characters or if the string consists only of white space characters. Otherwise, false is returned.

Example

isEmpty("");       // returns true
isEmpty("   ");    // returns true
isEmpty("  abc");  // returns false
isEmpty("a");      // returns false

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

Inputs

Outputs

Modelica.Utilities.Strings.count

Count the number of non-overlapping occurrences of a string

Information

Syntax

Strings.count(string, searchString)
Strings.count(string, searchString, startIndex=1,
                     caseSensitive=true)

Description

Returns the number of non-overlapping occurrences of string "searchString" in "string". The search is started at index "startIndex" (default = 1). If the optional argument "caseSensitive" is false, for the counting it does not matter whether a letter is upper or lower case.

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

Inputs

Outputs

Modelica.Utilities.Strings.find

Find first occurrence of a string within another string

Information

Syntax

index = Strings.find(string, searchString);
index = Strings.find(string, searchString, startIndex=1,
                     caseSensitive=true);

Description

Finds first occurrence of "searchString" within "string" and return the corresponding index. Start search at index "startIndex" (default = 1). If the optional argument "caseSensitive" is false, lower and upper case are ignored for the search. If "searchString" is not found, a value of "0" is returned.

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

Inputs

Outputs

Modelica.Utilities.Strings.findLast

Find last occurrence of a string within another string

Information

Syntax

index = Strings.findLast(string, searchString);
index = Strings.findLast(string, searchString,
                         startIndex=length(string), caseSensitive=true,

Description

Finds first occurrence of "searchString" within "string" when searching from the last character of "string" backwards, and return the corresponding index. Start search at index "startIndex" (default = 0; if startIndex = 0, search starts at length(string)). If the optional argument "caseSensitive" is false, lower and upper case are ignored for the search. If "searchString" is not found, a value of "0" is returned.

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

Inputs

Outputs

Modelica.Utilities.Strings.replace

Replace non-overlapping occurrences of a string from left to right

Information

Syntax

Strings.replace(string, searchString, replaceString);
Strings.replace(string, searchString, replaceString,
                startIndex=1, replaceAll=true, caseSensitive=true);

Description

Search in "string" for "searchString" and replace the found substring by "replaceString".

• The search starts at the first character of "string", or at character position "startIndex", if this optional argument is provided.
• If the optional argument "replaceAll" is true (default), all occurrences of "searchString" are replaced. If the argument is false, only the first occurrence is replaced.
• The search for "searchString" distinguishes upper and lower case letters. If the optional argument "caseSensitive" is false, the search ignores whether letters are upper or lower case.

The function returns the "string" with the performed replacements.

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

Inputs

Outputs

Modelica.Utilities.Strings.sort

Sort vector of strings in alphabetic order

Information

Syntax

stringVector2 = Streams.sort(stringVector1);
stringVector2 = Streams.sort(stringVector1, caseSensitive=true);

Description

Function sort(..) sorts a string vector stringVector1 in lexicographical order and returns the result in stringVector2. If the optional argument "caseSensitive" is false, lower and upper case letters are not distinguished.

Example

s1 = {"force", "angle", "pressure"};
s2 = Strings.sort(s1);
     -> s2 = {"angle", "force", "pressure"};

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

Inputs

Outputs

Modelica.Utilities.Strings.hashString

Create a hash value of a string

Information

Syntax

hash = Strings.hashString(string);

Description

Returns an Integer hash value of the provided string (the hash can be any Integer, including zero or a negative number).

Example

hashString("this is a test")     // =  1827717433
hashString("Controller.noise1")  // = -1025762750

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

Inputs

Outputs

Modelica.Utilities.Strings.scanToken

Scan for the next token and return it

Information

Syntax

(token, nextIndex) = Strings.scanToken(string, startIndex, unsigned=false);

Description

Function scanToken scans the string starting at index "startIndex" and returns the next token, as well as the index directly after the token. The returned token is a record that holds the type of the token and the value of the token:

Variable token.tokenType is an enumeration (emulated as a package with constants) that can have the following values:

import T = Modelica.Utilities.Types.TokenType;

Modelica line comments ("// ... end-of-line/end-of-string") as well as white space is ignored. If "unsigned=true", a Real or Integer literal is not allowed to start with a "+" or "-" sign.

Example

import Modelica.Utilities.Strings;
import T = Modelica.Utilities.Types.TokenType;
(token, index) := Strings.scanToken(string);
if token.tokenType == T.RealToken then
   realValue := token.real;
elseif token.tokenType == T.IntegerToken then
   integerValue := token.integer;
elseif token.tokenType == T.BooleanToken then
   booleanValue := token.boolean;
elseif token.tokenType == T.Identifier then
   name := token.string;
else
   Strings.syntaxError(string,index,"Expected Real, Integer, Boolean or identifier token");
end if;

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

Inputs

Outputs

Modelica.Utilities.Strings.scanReal

Scan for the next Real number and trigger an assert if not present

Information

Syntax

             number = Strings.scanReal(string);
(number, nextIndex) = Strings.scanReal(string, startIndex=1,
                                            unsigned=false, message="");

Description

The first form, "scanReal(string)", scans "string" for a Real number with leading white space and returns the value.

The second form, "scanReal(string,startIndex,unsigned)", scans the string starting at index "startIndex", checks whether the next token is a Real literal and returns its value as a Real number, as well as the index directly after the Real number. If the optional argument "unsigned" is true, the real number shall not have a leading "+" or "-" sign.

If the required Real number with leading white space is not present in "string", an assert is triggered.

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

Inputs

Outputs

Modelica.Utilities.Strings.scanInteger

Scan for the next Integer number and trigger an assert if not present

Information

Syntax

             number = Strings.scanInteger(string);
(number, nextIndex) = Strings.scanInteger(string, startIndex=1,
                                               unsigned=false, message="");

Description

Function scanInteger scans the string starting at index "startIndex", checks whether the next token is an Integer literal and returns its value as an Integer number, as well as the index directly after the Integer number. An assert is triggered, if the scanned string does not contain an Integer literal with optional leading white space.

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

Inputs

Outputs

Modelica.Utilities.Strings.scanBoolean

Scan for the next Boolean number and trigger an assert if not present

Information

Syntax

             number = Strings.scanBoolean(string);
(number, nextIndex) = Strings.scanBoolean(string, startIndex=1, message="");

Description

Function scanBoolean scans the string starting at index "startIndex", checks whether the next token is a Boolean literal (i.e., is either the string "false" or "true", if converted to lower case letters) and returns its value as a Boolean number, as well as the index directly after the Boolean number. An assert is triggered, if the scanned string does not contain a Boolean literal with optional leading white space.

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

Inputs

Outputs

Modelica.Utilities.Strings.scanString

Scan for the next Modelica string and trigger an assert if not present

Information

Syntax

             string2 = Strings.scanString(string);
(string2, nextIndex) = Strings.scanString(string, startIndex=1, message="");

Description

Function scanString scans the string starting at index "startIndex", checks whether the next token is a String literal and returns its value as a String, as well as the index directly after the String. An assert is triggered, if the scanned string does not contain a String literal with optional leading white space.

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

Inputs

Outputs

Modelica.Utilities.Strings.scanIdentifier

Scan for the next Identifier and trigger an assert if not present

Information

Syntax

             identifier = Strings.scanIdentifier(string);
(identifier, nextIndex) = Strings.scanIdentifier(string, startIndex=1, message="");

Description

Function scanIdentifier scans the string starting at index "startIndex", checks whether the next token is an Identifier and returns its value as a string, as well as the index directly after the Identifier. An assert is triggered, if the scanned string does not contain an Identifier with optional leading white space.

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

Inputs

Outputs

Modelica.Utilities.Strings.scanDelimiter

Scan for the next delimiter and trigger an assert if not present

Information

Syntax

             delimiter = Strings.scanDelimiter(string);
(delimiter, nextIndex) = Strings.scanDelimiter(string, startIndex=1,
                                 requiredDelimiters={","}, message="");

Description

Function scanDelimiter scans the string starting at index "startIndex", checks whether the next token is a delimiter string and returns its value as a string, as well as the index directly after the delimiter. An assert is triggered, if the scanned string does not contain a delimiter out of the list of requiredDelimiters. Input argument requiredDelimiters is a vector of strings. The elements may have any length, including length 0. If an element of the requiredDelimiters is zero, white space is treated as delimiter. The function returns delimiter="" and nextIndex is the index of the first non white space character.

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

Inputs

Outputs

Modelica.Utilities.Strings.scanNoToken

Scan string and check that it contains no more token

Information

Syntax

Strings.scanNoToken(string, startIndex=1, message="");

Description

Function scanNoToken scans the string starting at index "startIndex" and checks whether there is no more token in the string. An assert is triggered if this is not the case, using the "message" argument as additional explanation in the error text.

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

Inputs

Modelica.Utilities.Strings.syntaxError

Print an error message, a string and the index at which scanning detected an error

Information

Syntax

Strings.syntaxError(string, index, message);

Description

Function syntaxError prints an error message in the following form:

Syntax error at column <index> of
<string>
    ^       // shows character that is wrong
<message>

where the strings within <..> are the actual values of the input arguments of the function.

If the given string is too long, only a relevant part of the string is printed.

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

Inputs