Symbol -- the class of all symbols

Description

Symbols are entered as an alphabetic character followed by a sequence of alphanumeric characters; case is significant. The single symbol character ' is regarded as alphabetic, so that symbols such as x' may be used.

Symbols are used as names for values to be preserved, as indeterminates in polynomial rings, and as keys in hash tables. They may have global scope, meaning they are visible from every line of code, or local scope, with visibility restricted to a single file or function body.

i1 : x

o1 = x

o1 : Symbol

i2 : ab12

o2 = ab12

o2 : Symbol

Types of symbol:

Keyword -- the class of all keywords

Functions and methods returning a symbol:

global -- get a global symbol
Dictionary # String -- see List # ZZ -- get value from list, hash table, database, dictionary, or string
local -- get a local symbol
symbol -- get a symbol
threadLocal -- create a symbol whose value in one thread is not shared with others

Methods that use a symbol:

Symbol ? IndexedVariable -- see ? -- comparison operator
? Symbol -- view brief documentation of a symbol
about(Symbol) -- see about -- search the documentation
addHook(Symbol,Function) -- see addHook -- add a hook function to an object for later processing
autoload(Symbol,String) -- see autoload -- arrange for a function to be loaded automatically
baseName(Symbol) -- see baseName -- the base name of a generator
code(Symbol) -- see code -- display source code
concatenate(Symbol) -- see concatenate -- join strings
dictionary(Symbol) -- see dictionary -- determine the dictionary to which a symbol belongs
findSynonyms(Symbol) -- find synonyms of symbols
frames(Symbol) -- see frames -- get the frames associated to a closure
help(Symbol) -- see help -- view documentation nodes
hooks(Symbol) -- see hooks -- list hooks attached to a key
installAssignmentMethod(Symbol,HashTable,Function) -- see installing assignment methods -- install methods assignment to the value of an operator
installAssignmentMethod(Symbol,HashTable,HashTable,Function) -- see installing assignment methods -- install methods assignment to the value of an operator
installAssignmentMethod(Symbol,HashTable,HashTable,Option) -- see installing assignment methods -- install methods assignment to the value of an operator
installAssignmentMethod(Symbol,HashTable,Option) -- see installing assignment methods -- install methods assignment to the value of an operator
localDictionaries(Symbol) -- see localDictionaries -- get local dictionaries
locate(Symbol) -- see locate -- locate source code
methods(Symbol) -- see methods -- list methods
package(Symbol) -- see package -- get containing package
File << Symbol -- see printing to a file -- print to a file
runHooks(Symbol,Thing) -- see runHooks -- run the hook functions stored in an object
Symbol .. Symbol -- sequences of consecutive symbols
Symbol ..< Symbol -- sequences of consecutive symbols
Symbol _ Ring -- get a ring variable by name
Symbol _ Thing -- index variable
Symbol _ Thing = Thing -- assignment to an indexed variable
value(Symbol) -- retrieve the value of a symbol

For the programmer

The object Symbol is a type, with ancestor class Thing.

The source of this document is in Macaulay2Doc/ov_language.m2:990:0.