Manual a little more clear about string->number coersions
diff --git a/manual/manual.of b/manual/manual.of
index 61d4afa..d5b4a57 100644
--- a/manual/manual.of
+++ b/manual/manual.of
@@ -1406,10 +1406,9 @@
exp @bnfter{,} exp @bnfopt{@bnfter{,} exp} @Rw{do} block @Rw{end}}
}
The given identifier (@bnfNter{Name}) defines the control variable,
-which is local to the loop body (@emph{block}).
+which is a new variable local to the loop body (@emph{block}).
-The loop starts by evaluating once the three control expressions;
-they must all result in numbers.
+The loop starts by evaluating once the three control expressions.
Their values are called respectively
the @emph{initial value}, the @emph{limit}, and the @emph{step}.
If the step is absent, it defaults @N{to 1}.
@@ -1417,8 +1416,9 @@
If both the initial value and the step are integers,
the loop is done with integers;
note that the limit may not be an integer.
-Otherwise, the loop is done with floats.
-(Beware of floating-point accuracy in this case.)
+Otherwise, the three values are converted to
+floats and the loop is done with floats.
+Beware of floating-point accuracy in this case.
After that initialization,
the loop body is repeated with the value of the control variable
@@ -1773,9 +1773,24 @@
Otherwise, the conversion fails.
Several places in Lua coerce strings to numbers when necessary.
+In particular,
+the string library sets metamethods that try to coerce
+strings to numbers in all arithmetic operations.
+If the conversion fails,
+the library calls the metamethod of the other operand
+(if present) or it raises an error.
+Note that bitwise operators do not do this coercion.
+
+Nonetheless, it is always a good practice not to rely on these
+implicit coercions, as they are not always applied;
+in particular, @T{"1"==1} is false and @T{"1"<1} raises an error
+@see{rel-ops}.
+These coercions exist mainly for compatibility and may be removed
+in future versions of the language.
+
A string is converted to an integer or a float
following its syntax and the rules of the Lua lexer.
-(The string may have also leading and trailing whitespaces and a sign.)
+The string may have also leading and trailing whitespaces and a sign.
All conversions from strings to numbers
accept both a dot and the current locale mark
as the radix character.
@@ -1783,15 +1798,9 @@
If the string is not a valid numeral,
the conversion fails.
If necessary, the result of this first step is then converted
-to the required number subtype following the previous rules
+to a specific number subtype following the previous rules
for conversions between floats and integers.
-The string library uses metamethods that try to coerce
-strings to numbers in all arithmetic operations.
-If the conversion fails,
-the library calls the metamethod of the other operand
-(if present) or it raises an error.
-
The conversion from numbers to strings uses a
non-specified human-readable format.
To convert numbers to strings in any specific way,
@@ -7687,8 +7696,8 @@
It provides all its functions and constants inside the table @defid{math}.
Functions with the annotation @St{integer/float} give
integer results for integer arguments
-and float results for float (or mixed) arguments.
-the rounding functions
+and float results for non-integer arguments.
+The rounding functions
@Lid{math.ceil}, @Lid{math.floor}, and @Lid{math.modf}
return an integer when the result fits in the range of an integer,
or a float otherwise.
@@ -7843,7 +7852,7 @@
but they are not cryptographically secure.
(For instance, there are no guarantees that it is hard
to predict future results based on the observation of
-some number of previous results.)
+some previous results.)
}
