SetStringMid , StringMid , String, Atom , ConcatStrings , LocalSymbols , PatchString .

String manipulation

SetStringMid change a substring
StringMid retrieve a substring
String, Atom convert atom to string and vice versa
ConcatStrings concatenate strings
LocalSymbols create unique local symbols with given prefix
PatchString execute commands between <? and ?> in strings

SetStringMid -- change a substring

Internal function
Calling format: 
SetStringMid(index,substring,string)

Parameters:
index -- index of substring to get

substring -- substring to store

string -- string to store substring in.

Description:
Set (change) a part of a string. It leaves the original alone, returning a new changed copy.

Examples: 
In> SetStringMid(3,"XY","abcdef")
Out> "abXYef";

See also:
StringMid , Length .

StringMid -- retrieve a substring

Internal function
Calling format: 
StringMid(index,length,string)

Parameters:
index -- index of substring to get

length -- length of substring to get

string -- string to get substring from

Description:
StringMid returns a part of a string. Substrings can also be accessed using the [] operator.

Examples: 
In> StringMid(3,2,"abcdef")
Out> "cd";
In> "abcdefg"[2 .. 4]
Out> "bcd";

See also:
SetStringMid , Length .

String, Atom -- convert atom to string and vice versa

Internal function
Calling format: 
Atom("string")
String(atom)

Parameters:
atom -- an atom

"string" -- a string

Description:
Returns an atom with the string representation given as the evaluated argument. Example: Atom("foo"); returns foo.

String is the inverse of Atom: turns atom into "atom".

Examples: 
In> String(a)
Out> "a";
In> Atom("a")
Out> a;

ConcatStrings -- concatenate strings

Internal function
Calling format: 
ConcatStrings(strings)

Parameters:
strings -- one or more strings

Description:
Concatenates strings.

Examples: 
In> ConcatStrings("a","b","c")
Out> "abc";

See also:
: .

LocalSymbols -- create unique local symbols with given prefix

Standard library
Calling format: 
LocalSymbols(var1, var2, ...) body

Parameters:
var1, var2, ... -- atoms, symbols to be made local

body -- expression to execute

Description:
Given the symbols passed as the first arguments to LocalSymbols a set of local symbols will be created, and creates unique ones for them, typically of the form $<symbol><number>, where symbol was the symbol entered by the user, and number is a unique number. This scheme was used to ensure that a generated symbol can not accidentally be entered by a user.

This is useful in cases where a guaranteed free variable is needed, for example, in the macro-like functions (For, While, etc.).

Examples: 
In> LocalSymbols(a,b)a+b
Out> $a6+ $b6;

See also:
UniqueConstant .

PatchString -- execute commands between <? and ?> in strings

Internal function
Calling format: 
PatchString(string)

Parameters:
string -- a string to patch

Description:
This function does the same as PatchLoad, but it works on a string in stead of on the contents of a text file. See PatchLoad for more details.

Examples: 
In> PatchString("Two plus three \
  is <? Write(2+3); ?> ");
Out> "Two plus three is 5 ";

See also:
PatchLoad .