25149: add C_PRECEDENCES option to make arithmetic have C/Perl precedence

2 files changed, 35 insertions, 2 deletions

diff --git a/Doc/Zsh/arith.yo b/Doc/Zsh/arith.yo
index d7f1ae608..423e6c1bc 100644
--- a/Doc/Zsh/arith.yo
+++ b/Doc/Zsh/arith.yo
@@ -91,8 +91,8 @@ taken for a parameter name.
 
 cindex(arithmetic operators)
 cindex(operators, arithmetic)
-An arithmetic expression uses nearly the same syntax, precedence, and
-associativity of expressions in C.
+An arithmetic expression uses nearly the same syntax and
+associativity of expressions as in C.
 The following operators are supported (listed in decreasing order
 of precedence):
 
@@ -119,6 +119,29 @@ short-circuiting, and only one of the latter two expressions in a ternary
 operator is evaluated.  Note the precedence of the bitwise AND, OR,
 and XOR operators.
 
+With the option tt(C_PRECEDENCES) the precedences (but no other
+properties) of the operators are altered to be the same as those in
+most other languages that support the relevant operators:
+
+startsitem()
+sitem(tt(PLUS() - ! ~ PLUS()PLUS() --))(unary plus/minus, logical NOT, complement, {pre,post}{in,de}crement)
+sitem(tt(**))(exponentiation)
+sitem(tt(* / %))(multiplication, division, modulus (remainder))
+sitem(tt(PLUS() -))(addition, subtraction)
+sitem(tt(<< >>))(bitwise shift left, right)
+sitem(tt(< > <= >=))(comparison)
+sitem(tt(== !=))(equality and inequality)
+sitem(tt(&))(bitwise AND)
+sitem(tt(^))(bitwise XOR)
+sitem(tt(|))(bitwise OR)
+sitem(tt(&&))(logical AND)
+sitem(tt(^^))(logical XOR)
+sitem(tt(||))(logical OR)
+sitem(tt(? :))(ternary operator)
+sitem(tt(= PLUS()= -= *= /= %= &= ^= |= <<= >>= &&= ||= ^^= **=))(assignment)
+sitem(tt(,))(comma operator)
+endsitem()
+
 cindex(mathematical functions, use of)
 cindex(functions, math, use of)
 Mathematical functions can be called with the syntax
diff --git a/Doc/Zsh/options.yo b/Doc/Zsh/options.yo
index e2e36dc5f..eec951d4f 100644
--- a/Doc/Zsh/options.yo
+++ b/Doc/Zsh/options.yo
@@ -1036,6 +1036,16 @@ on the choice of the output base, nor on the output of bases other than
 hexadecimal and octal.  Note that these formats will be understood on input
 irrespective of the setting of tt(C_BASES).
 )
+pindex(C_PRECEDENCES)
+cindex(precedence, operator)
+cindex(operator precedence)
+item(tt(C_PRECEDENCES))(
+This alters the precedence of arithemtic operators to be more
+like C and other programming languages;
+ifnzman(Arithmetic Evaluation)\
+ifzman(the section ARITHMETIC EVALUATION in zmanref(zshmisc))
+has an explicit list.
+)
 pindex(DEBUG_BEFORE_CMD)
 cindex(traps, DEBUG, before or after command)
 cindex(DEBUG trap, before or after command)