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-rw-r--r--software/functional programming.page38
1 files changed, 19 insertions, 19 deletions
diff --git a/software/functional programming.page b/software/functional programming.page
index 593cf41..7fa1358 100644
--- a/software/functional programming.page
+++ b/software/functional programming.page
@@ -24,31 +24,31 @@ 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):
->>> l = 0
->>> while x.has_next()
->>> l = l+1;
->>> x.pop()
->>> return l
+ def how-long(x):
+ l = 0
+ 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()
->>> x.pop()
->>> return how-long-recurse(x) + 1
->>> else
->>> return 0
+ def how-long-recurse(x):
+ if x.has_next()
+ x.pop()
+ 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()
->>> return col(0)
->>> else
->>> x.pop()
->>> return how-long-col(x, lambda a: col(add1(a)))
+ def add1(x): return a+1;
+ def how-long-col(x, col):
+ if x.has_next()
+ return col(0)
+ else
+ x.pop()
+ 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