X → Boolean Conversions

This topic provides a reference table for all automatic type conversions to boolean, sorted by merit.

Fair Conversions

This section lists all fair conversions to the boolean type. A 'Fair' conversion indicates the types involved are closesly related in a data layout sense, though not necessarily in a conceptual sense. For example booleans and integers, or points and vectors. Although these conversions may fail or narrow, it is nevertheless considered decent practice to rely upon them in algorithms.

From	Explanation
angle	Returns true for all angles except those near zero.
integer	Returns true for all integers except zero.
integer (big)	Returns true for all integers except zero.
number	Returns true for all numbers except those near zero.

Plausible Conversions

This section lists all plausible conversions to the boolean type. A 'Plausible' conversion indicates a non-straightforward, but a still reasonable conversion between two types that share a salient quality, or where one is an obvious sub-type of the other. For example curves and intervals, or points and planes. Any plausible conversion can also be achieved through the explicit use of standard components.

From	Explanation
complex number	Returns true for all complex numbers except those near zero.
interval	Returns true for all intervals except near-empty ones.

Strange Conversions

This section lists all strange conversions to the boolean type. A 'Strange' conversion indicates a peculiar, but occasionally sensible, translation between types. However, it is equally likely that the conversion was not intended and thus represents a mistake in the algorithm design, which is why this conversion level is the default for showing conversion warnings in the Grasshopper interface. Examples in this category include the conversion between colours and booleans, or between circles and triangles. Any strange conversion can also be achieved through the explicit use of standard components.

From	Explanation
arc	Returns true for closed curves, false for open curves.
box	Solid shapes become 'true', open shapes become 'false'.
brep	Returns true for closed breps, false for open breps.
circle	Returns true for closed curves, false for open curves.
colour	Returns true for all colors except black.
Colour (RGB)	Returns true for all colors except black.
curve	Returns true for closed curves, false for open curves.
line	Returns true for closed curves, false for open curves.
mesh	Returns true for closed meshes, false for open meshes.
polyline	Returns true for closed curves, false for open curves.
rectangle	Returns true for closed curves, false for open curves.
sphere	Solid shapes become 'true', open shapes become 'false'.
SubD	Returns true for closed SubDs, false for open SubDs.
surface	Returns true for closed surfaces, false for open surfaces..
triangle	Returns true for closed curves, false for open curves.
tube	Solid shapes become 'true', open shapes become 'false'.
vector	Returns true for all vectors except those with near-zero length.