diff options
Diffstat (limited to 'doc/manual/syntax.txt')
| -rw-r--r-- | doc/manual/syntax.txt | 25 |
1 files changed, 12 insertions, 13 deletions
diff --git a/doc/manual/syntax.txt b/doc/manual/syntax.txt index c975e7f48..24644bce2 100644 --- a/doc/manual/syntax.txt +++ b/doc/manual/syntax.txt @@ -12,13 +12,9 @@ Binary operators have 11 different levels of precedence. Associativity ------------- -Binary operators whose first character is ``^`` or its last character -is ``>`` are right-associative, all other binary operators are left-associative. +Binary operators whose first character is ``^`` are right-associative, all +other binary operators are left-associative. -Exception: The single "greater than" ``>`` operator is left-associative too. - -Operators ending in ``>`` but longer than a single character are -called `arrow like`:idx:. Precedence @@ -35,9 +31,12 @@ as ``(@x).abc`` whereas ``$x.abc`` is parsed as ``$(x.abc)``. For binary operators that are not keywords the precedence is determined by the following rules: +Operators ending in either ``->``, ``~>`` or ``=>`` are called +`arrow like`:idx:, and have the lowest precedence of all operators. + If the operator ends with ``=`` and its first character is none of ``<``, ``>``, ``!``, ``=``, ``~``, ``?``, it is an *assignment operator* which -has the lowest precedence. +has the second lowest precedence. Otherwise precedence is determined by the first character. @@ -45,14 +44,14 @@ Otherwise precedence is determined by the first character. Precedence level Operators First character Terminal symbol ================ =============================================== ================== =============== 10 (highest) ``$ ^`` OP10 - 9 ``* / div mod shl shr %`` ``* % \ /`` OP9 - 8 ``+ -`` ``+ ~ |`` OP8 + 9 ``* / div mod shl shr %`` ``* % \ /`` OP9 + 8 ``+ -`` ``+ - ~ |`` OP8 7 ``&`` ``&`` OP7 6 ``..`` ``.`` OP6 - 5 ``== <= < >= > != in notin is isnot not of`` ``= < > !`` OP5 + 5 ``== <= < >= > != in notin is isnot not of`` ``= < > !`` OP5 4 ``and`` OP4 3 ``or xor`` OP3 - 2 ``@ : ?`` OP2 + 2 ``@ : ?`` OP2 1 *assignment operator* (like ``+=``, ``*=``) OP1 0 (lowest) *arrow like operator* (like ``->``, ``=>``) OP0 ================ =============================================== ================== =============== @@ -61,7 +60,7 @@ Precedence level Operators First charact Strong spaces ------------- -The number of spaces preceeding a non-keyword operator affects precedence +The number of spaces preceding a non-keyword operator affects precedence if the experimental parser directive ``#!strongSpaces`` is used. Indentation is not used to determine the number of spaces. If 2 or more operators have the same number of preceding spaces the precedence table applies, so ``1 + 3 * 4`` @@ -69,7 +68,7 @@ is still parsed as ``1 + (3 * 4)``, but ``1+3 * 4`` is parsed as ``(1+3) * 4``: .. code-block:: nim #! strongSpaces - if foo+4 * 4 == 8 and b&c | 9 ++ + if foo+4 * 4 == 8 and b&c | 9 ++ bar: echo "" # is parsed as |