gsl-shell.git - gsl-shell

diff --git a/doc/user-manual/lua-base.rst b/doc/user-manual/lua-base.rst
index 16ea768f..d46c7d39 100644
--- a/doc/user-manual/lua-base.rst
+++ b/doc/user-manual/lua-base.rst

@@ -7,18 +7,18 @@

Iterators

============================

-GSL Shell provides some simple functions to perform some common tasks related to iterators.

-The utilization of these functions allows to write more simple and compact code and to improve the readability.

-The functions describes below are available in the module :mod:`iter`.

+GSL Shell provides a number of simple functions to perform some common tasks related to iterators.

+These functions allow you to write more simple and compact code and to improve the readability.

+The functions described below are available in the module :mod:`iter`.

.. module:: iter

.. function:: sequence(f, a, b)

sequence(f, b)

- Return an "iterator" that gives the value (or the values) returned by the evaluation of ``f(i)`` where ``i`` is an integer that goes from ``a`` to ``b``. In the second form the generated values start from one.

+ Return an "iterator" that gives the value (or the values) returned by the evaluation of ``f(i)`` where ``i`` is an integer that goes from ``a`` to ``b``. In the second form, the generated values start from one.

- Generally, an iterator is a function that, each time that it is called, return one value from a sequence. The sequence is considered to be terminated when the iterator returns ``nil``. An iterator can be used directly in a ``for`` loop with the following syntax::

+ Generally, an iterator is a function that, each time that it is called, returns one value from a sequence. The sequence is considered to be terminated when the iterator returns ``nil``. An iterator can be used directly in a ``for`` loop with the following syntax::

for a, b, ... in f do

-- [ some code here]

@@ -28,7 +28,7 @@ The functions describes below are available in the module :mod:`iter`.

.. function:: sample(f, xi, xs, n)

- Return an iterators that gives the couple ``x, f(x)`` for ``x`` going from ``xi`` to ``xs`` with ``n`` uniformly spaced intervals. If ``f`` returns multiple values only the first one is retained.

+ Return an iterator that gives the couple ``x, f(x)`` for ``x`` going from ``xi`` to ``xs`` with ``n`` uniformly spaced intervals. If ``f`` returns multiple values, only the first one is retained.

Example::

@@ -40,19 +40,19 @@ The functions describes below are available in the module :mod:`iter`.

.. function:: isample(f, a, b)

isample(f, b)

- Return an iterators that gives the couple ``i, f(i)`` where ``i`` is an integer going from ``a`` to ``b``. In the second form the sequence will start from one. If ``f`` returns multiple values only the first one is retained.

+ Return an iterator that gives the couple ``i, f(i)`` where ``i`` is an integer going from ``a`` to ``b``. In the second form, the sequence will start from one. If ``f`` returns multiple values, only the first one is retained.

.. function:: ilist(f, a, b)

ilist(f, b)

Returns a list with the elements ``f(i)`` where ``i`` is an integer going from a to b.

- In the second form the sequence will start from one.

+ In the second form, the sequence will start from one.

.. function:: isum(f, a, b)

isum(f, b)

Returns the sum of ``f(i)`` for all integers ``i`` from a to b.

- In the second form the sequence will start from one.

+ In the second form, the sequence will start from one.

@@ -65,7 +65,7 @@ Actually the more general form of an iterator is the following::

-- [ some code here]

end

-In this latter form the iterator f is called in the form ``f(s, i)`` where ``s`` is the value provided in the ``for`` loop. The value of ``i`` changes every time, the value taken is the the first value returned by the function ``f`` the last times it was called or, for the first time only, ``i0``.

+In this latter form, the iterator f is called in the form ``f(s, i)``, where ``s`` is the value provided in the ``for`` loop. The value of ``i`` changes every time, the value taken is the first value returned by the function ``f`` the last times it was called or, for the first time only, ``i0``.

We give an example to build a stateless row "iterator" over the rows of a matrix.::