diff options
Diffstat (limited to 'README')
| -rw-r--r-- | README | 49 |
1 files changed, 45 insertions, 4 deletions
diff --git a/README b/README index 4d2b6c17e..94df2a561 100644 --- a/README +++ b/README @@ -38,10 +38,12 @@ details, see the documentation. Incompatibilites between 5.0.7 and 5.0.8 ---------------------------------------- -A couple of arithmetic operations have changed: the new behaviour -is intended to be more consistent, but is not compatible with the old. +Various arithmetic operations have changed, in particular with respect +to the choice of integer or floating point operations. The new +behaviour is intended to be more consistent, but is not compatible with +the old. -Previously, the modulus operation, `%', implicitly converted the +1) Previously, the modulus operation, `%', implicitly converted the operation to integer and output an integer result, even if one or both of the arguments were floating point. Now, the C math library fmod() operator is used to implement the operation where @@ -57,7 +59,8 @@ New behaviour: % print $(( 5.5 % 2 )) 1.5 -Previously, assignments to variables assigned the correct type to + +2) Previously, assignments to variables assigned the correct type to variables declared as floating point or integer, but this type was not propagated to the value of the expression, as a C programmer would naturally expect. Now, the type of the variable is propagated @@ -81,6 +84,44 @@ New behaviour: % print $var 2 + +3) Previously, the FORCE_FLOAT option only forced the use of floating +point in arithmetic expressions for integer constants, i.e. numbers +typed directly into the expression, but not for variables. Hence +an operation involving only integer variables (or string variables +containing integers) was not forced to be performed with floating point +arithmetic. Now, operations involving variables are also forced to +floating point. For example: + +Old behaviour: + +% unsetopt FORCE_FLOAT +% print $(( 1 / 2 )) +0 +% integer i=1 j=2 +% print $(( i / j )) +0 +% setopt FORCE_FLOAT +% print $(( 1 / 2 )) +0.5 +% print $(( i / j )) +0 + +New behaviour: + +% unsetopt FORCE_FLOAT +% print $(( 1 / 2 )) +0 +% integer i=1 j=2 +% print $(( i / j )) +0 +% setopt FORCE_FLOAT +% print $(( 1 / 2 )) +0.5 +% print $(( i / j )) +0.5 + + Incompatibilities between 5.0.2 and 5.0.5 ----------------------------------------- |