Programs->R2->Reference

Reference

    Reference

Note: these pages use the APL2741 or APLSans font, both available from Causeway.

R2 Reference

This is a list of all the tokens R2 recognises, and what arguments they can take. The following abbreviations for data types are used:

i: Integer n: Number c: Character s: String

v: Vector (eg nv=vector of numbers) a: Array (ia=array of integers only) null: Null {data}: data is shy.

Primitives

Symbol	Niladic	Monadic	Dyadic
`+`	n/a	`a„+ a` Makes everything on the stack non-shy.	`na„na + na` Add
`-`	n/a	`na„- na` Negate	`na„na - na` Subtract
`÷`	n/a	`na„÷ na` Reciprocal	`na„na ÷ na` Divide
`×`	n/a	`ia„× na` Sign (1/0/-1)	`na„na × na` Multiply
`*`	n/a	`na„* na` Exponenitate	`na„na * na` Power
`—`	n/a	`ia„— na` Ceiling	`na„na — na` Max
`˜`	n/a	`ia„˜ na` Floor	`na„na ˜ na` Min
`^`	n/a	n/a	`ia„ia ^ ia` Bitwise And
`Ÿ`	n/a	n/a	`ia„ia Ÿ ia` Bitwise Or
`Š`	n/a	n/a	`ia„ia Š ia` Bitwise Nand (Not-And)
`‹`	n/a	n/a	`ia„ia ‹ ia` Bitwise Nor (Not-Or)
`„`	n/a	`{a}„ „ {a}` Sink (makes everything on the stack shy)	`a„Identifier „ a Assign`
`…`	n/a	`…i/Label` Goto	`a„a … ia Get items by index`
`¼`	n/a	`iv„¼ i` The integers 1..n	`a„a ¼ a Index of one array in another`
`½`	n/a	`iv„½ a` Shape	`a„iv ½ a Reshape`
`/`	n/a	`a„Token/ a` Inserts the token between each pair of elements; e.g. `+/[1 2 3]` is 6.	`a„iv / a` Compress
`«`	Null	Null	Null

System Functions

Function	Niladic	Monadic	Dyadic
`ŒDEPTH`	`i„ŒDEPTH` The depth of the function stack	n/a	n/a
`ŒED`	n/a	`ŒED c/cv/s` Edits a function or variable	n/a
`ŒEX`	n/a	`ŒEX c/cv/s` Deletes a function or variable	n/a
`ŒOFF`	`i„ŒOFF` Exits R2. If it returns, the value is 0.	n/a	n/a

System Variables

Variable	Read-Only	Type	Meaning
`ŒA`	Yes	cv	The uppercase alphabet
`ŒALOW`	Yes	cv	The lowercase alphabet
`ŒABOTH`	Yes	cv	The uppercase alphabet, followed by the lowercase alphabet
`ŒAV`	Yes	cv	The complete character set
`ŒD`	Yes	cv	The digits
`ŒGLOBALS`	Yes	cv	The characters which when used as the first letter of a name define that name to be global. This is set to `‘Œ`
`ŒIO`	Yes	i	Index origin; fixed to 1
`ŒSHOWH`