Expression

Arg

Syntax: y = Arg( x, i )

Description: Returns the ith argument of the evaluated expression or Empty() if there is no ith argument.

JMP Version Added: Before version 14

Arg( Expr( Sum( a, b, c ) ), 2 );

Arg Expr

Syntax: y = Arg Expr( expr, i )

Description: Returns the ith argument of the expression or Empty() if there is no ith argument. This function is deprecated. Please use Arg() instead.

JMP Version Added: Before version 14

Example 1

// See Example 2 for the deprecated Arg Expr() equivalent
Arg( Expr( Sum( a, b, c ) ), 2 );

Example 2

// Deprecated
Arg Expr( Sum( a, b, c ), 2 );

Eval Expr

Syntax: y = Eval Expr( x )

Description: Returns a copy of expression x with each Expr() clause within x replaced with its evaluated value.

JMP Version Added: Before version 14

Eval Expr( Length( Expr( "X" || Char( 12 ) ) ) );

Expr

Syntax: y = Expr( x )

Description: Returns its argument unevaluated. Used to quote expressions.

JMP Version Added: Before version 14

Expr( x + y );

Extract Expr

Syntax: y = Extract Expr( expr, pattern )

Description: Returns a subexpression matching the specified pattern.

JMP Version Added: Before version 14

Extract Expr( a + b * c, Wild() * Wild() );

Head

Syntax: y = Head( x )

Description: Returns the head of the evaluated expression, without its arguments.

JMP Version Added: Before version 14

Head( Expr( Sum( a, b, c ) ) );

Head Expr

Syntax: y = Head Expr( expr )

Description: Returns the head of the expression, without its arguments. This function is deprecated. Please use Head() instead.

JMP Version Added: Before version 14

Example 1

// See Example 2 for the deprecated Head Expr() equivalent
Head( Expr( Sum( a, b, c ) ) );

Example 2

// Deprecated
Head Expr( Sum( a, b, c ) );

Head Name

Syntax: y = Head Name( x )

Description: Returns the head of the evaluated expression as a string, without its arguments.

JMP Version Added: Before version 14

Head Name( Expr( Sum( a, b, c ) ) );

Head Name Expr

Syntax: y = Head Name Expr( expr )

Description: Returns the head of the expression as a string, without its arguments. This function is deprecated. Please use Head Name() instead.

JMP Version Added: Before version 14

Example 1

// See Example 2 for the deprecated Head Name Expr() equivalent
Head Name( Expr( Sum( a, b, c ) ) );

Example 2

// Deprecated
Head Name Expr( Sum( a, b, c ) );

N Arg

Syntax: n = N Arg( expr )

Description: Returns the number of arguments of the evaluated expression head.

JMP Version Added: Before version 14

N Arg( Expr( Sum( a, b, c ) ) );

N Arg Expr

Syntax: n = N Arg Expr( expr )

Description: Returns the number of arguments of the expression head. This function is deprecated. Please use N Arg() instead.

JMP Version Added: Before version 14

Example 1

// See Example 2 for the deprecated N Arg Expr() equivalent
N Arg( Expr( Sum( a, b, c ) ) );

Example 2

// Deprecated
N Arg Expr( Sum( a, b, c ) );

Name Expr

Syntax: y = Name Expr( x )

Description: Returns the value of a symbol, without evaluating it if it is an expression.

JMP Version Added: Before version 14

ex = Expr( 1 + 2 );
Eval List( {ex, Name Expr( ex )} );