WolframLang: Expression
WolframLang source code is made of expressions. Every part in source code, is expression. (there is no such thing as “statements”.)
What this means is that, any valid syntactic unit returns a value.
- Atom
- An atom is a indivisible expression, such as number, Symbol, String. [see Atomic Expression]
- Expression
-
Expression is either a single Atom , or a sequence of atoms in the form
a[b, c etc]
any of the a, b, c, etc, is again an expression.
this syntax is called FullForm
- Head of expression
- The a in
a[…]
is called the Head of expression. [see Head of Expression] - List
- A list is a expression whose head is
List
. [see List] - FullForm
-
- The form
a[…]
is called FullForm. - Atomic Expression such as number and string, are in FullForm by themself.
- The WolframEngine convert shortcut syntax to FullForm internally before eval.
- All Pattern Matching are done against FullForm.
[see WolframLang: FullForm Syntax]
Frequently used functions have syntax shortcuts. Example:
FullForm Shortcut Plus[3,4]
3+4
Rational[3,4]
3/4
List[3,4]
{3,4}
Equal[x,y]
x == y
SameQ[x,y]
x === y
Greater[x,y]
x > y
Set[x,3]
x = 3
- The form