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-rw-r--r--software/functional programming.page23
1 files changed, 12 insertions, 11 deletions
diff --git a/software/functional programming.page b/software/functional programming.page
index 7fa1358..2858a99 100644
--- a/software/functional programming.page
+++ b/software/functional programming.page
@@ -24,31 +24,32 @@ or variables in layer after layer of functions and just holding on to
the outermost layer. For instance, the typical way to write a ``length``
function in python would be::
- def how-long(x):
+ def how_long(x):
l = 0
- while x.has_next()
+ while x.has_next():
l = l+1;
x.pop()
return l
Using recursion, we could do::
- def how-long-recurse(x):
- if x.has_next()
+ def how_long_recurse(x):
+ if x.has_next():
x.pop()
- return how-long-recurse(x) + 1
- else
+ return how_long_recurse(x) + 1
+ else:
return 0
Using the collector paradigm, we could do::
- def add1(x): return a+1;
- def how-long-col(x, col):
- if x.has_next()
+ def add1(x): return x+1;
+ def how_long_col(x, col):
+ """call this as how_long_col(<collection>, lambda b: b)"""
+ if not x.has_next():
return col(0)
- else
+ else:
x.pop()
- return how-long-col(x, lambda a: col(add1(a)))
+ return how_long_col(x, lambda a: col(add1(a)))
The first two ways, the plus one operation is actually executed at any given
time, while with the collector implementation we're really creating a