23 Number Snip

method
(send a-number-snip:snip-class read f)
→(or/c (is-a?/c snip% )#f)
f:(is-a?/c editor-stream-in% )
Overrides read in snip-class% .
Constructs a number snip from its input.

procedure
( number-snip:number->string/snip
num
[ #:exact-prefixexact-prefix
#:inexact-prefixinexact-prefix
#:fraction-viewfraction-view])
→(or/c number-snip:is-number-snip? string? )
num:number?
exact-prefix:(or/c 'always'never'when-necessary)='never

inexact-prefix : (or/c 'always'never'when-necessary)
= 'never
fraction-view:(or/c #f'mixed'improper'decimal)=#f

For a number num, returns a number snip or a string according to the specified format arguments.

The exact-prefix argument specifies whether the representation should carry a #e prefix: Always, never, or when necessary to identify a representation that would otherwise be considered inexact.

Similarly for inexact-prefix. Note however that 'when-necessary is usually equivalent to 'never, as inexact numbers are always printed with a decimal dot, which is sufficient to identify a number representation as inexact.

The fraction-view field specifies how exact non-integer reals - fractions - should be rendered: As a mixed fraction, an improper fraction, or a decimal, possibly identifying periodic digits. For 'decimal, if it’s not possible to render the number as a decimal exactly, a fraction representation might be generated. This is currently the case for complex numbers.

If fraction-view is #f, this option comes from the 'framework:fraction-snip-style preference.

procedure
( number-snip:make-pretty-print-size
[ #:exact-prefixexact-prefix
#:inexact-prefixinexact-prefix
#:fraction-viewfraction-view])
→(number? boolean? output-port? . -> .exact-nonnegative-integer? )
exact-prefix:(or/c 'always'never'when-necessary)='never

inexact-prefix : (or/c 'always'never'when-necessary)
= 'never
fraction-view:(or/c #f'mixed'improper'decimal)=#f

This returns a procedure usable in a pretty-print-size-hook implementation, to go with number-snip:number->string/snip . The arguments are as with number-snip:number->string/snip .

procedure
( number-snip:make-repeating-decimal-snip num
show-prefix?)
→number-snip:is-number-snip?
num:real?
show-prefix?:boolean?

Makes a number snip that shows the decimal expansion for number. The boolean indicates if a #e prefix appears on the number.

procedure
( number-snip:make-fraction-snip num
show-prefix-in-decimal-view?)
→number-snip:is-number-snip?
num:real?
show-prefix-in-decimal-view?:boolean?

Makes a number snip that shows a fractional view of number. The boolean indicates if a #e prefix appears on the number, when shown in the decimal state.

procedure
( number-snip:is-number-snip? v)→boolean?
v:any/c

Determines if v is a number snip, i.e., created by number-snip:make-fraction-snip or number-snip:make-repeating-decimal-snip .

All values that answer #t to this predicate are also snip% s.

procedure
( number-snip:get-number ns)→real?
ns:number-snip:is-number-snip?

Returns the number that this number snip displays.

procedure
( number-snip:remove-decimal-looking-number-snips-on-insertion-mixin text%)
→(subclass?/c text%)
text%:(subclass?/c text%)

Overrides the on-insert and after-insert to replace number-snip% objects that look like ASCII with their corresponding ASCII text.

top ← prev up next →