Maybe just try renaming the offending function?

Author: jonathanhogg

src/flitter/language/functions/__init__.py

@@ -9,7 +9,7 @@
                    maxindex, maxv, minindex, minv, normalize, ordv, point_towards, qbetween, qmul, quaternion,
                    read_bytes, read_csv, read_text, sample, slerp, snap, sort, split, zipv)
 from .random import beta, normal, shuffle, uniform
-from .waves import bounce, impulse, sawtooth, sharkfin, sine, square, triangle
+from .waves import bounce, impulse, sawtooth, sharkfin, sine, square, triwave
 
 
 STATIC_FUNCTIONS = {
@@ -75,7 +75,7 @@
     'square': Vector(square),
     'sum': Vector(sumv),
     'tan': Vector(tanv),
-    'triangle': Vector(triangle),
+    'triangle': Vector(triwave),
     'uniform': Vector(uniform),
     'zip': Vector(zipv),
 }

src/flitter/language/functions/waves.pyx

@@ -74,7 +74,7 @@ def sawtooth(Vector xs not None):
     return ys
 
 
-def triangle(Vector xs not None):
+def triwave(Vector xs not None):
     if xs.numbers == NULL:
         return null_
     cdef Vector ys = Vector.__new__(Vector)