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authorJeremy Evans <code@jeremyevans.net>2021-05-13 15:31:46 -0700
committerJeremy Evans <code@jeremyevans.net>2021-07-15 09:56:02 -0700
commitfa87f72e1e84e2b55516be188f00434a683b924c (patch)
tree0c4efbae462e0ebae46447ea0e18bbea4d7821f0
parentf1035248af04b2a4d58990740c3f1b840a5eac78 (diff)
Add pattern matching pin support for instance/class/global variables
Pin matching for local variables and constants is already supported, and it is fairly simple to add support for these variable types. Note that pin matching for method calls is still not supported without wrapping in parentheses (pin expressions). I think that's for the best as method calls are far more complex (arguments/blocks). Implements [Feature #17724]
Notes
Notes: Merged: https://github.com/ruby/ruby/pull/4502
-rw-r--r--NEWS.md8
-rw-r--r--compile.c3
-rw-r--r--doc/syntax/pattern_matching.rdoc32
-rw-r--r--parse.y14
-rw-r--r--test/ruby/test_pattern_matching.rb24
5 files changed, 79 insertions, 2 deletions
diff --git a/NEWS.md b/NEWS.md
index 702803eee7f..5f0b5a6b2cf 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -14,6 +14,13 @@ Note that each entry is kept to a minimum, see links for details.
#=> [[3, 5], [5, 7], [11, 13]]
```
+* Pin operator now supports instance, class, and global variables.
+ [[Feature #17724]]
+
+ @n = 5
+ Prime.each_cons(2).lazy.find{_1 in [n, ^@n]}
+ #=> [3, 5]
+
* Multiple assignment evaluation order has been made consistent with
single assignment evaluation order. With single assignment, Ruby
uses a left-to-right evaluation order. With this code:
@@ -190,6 +197,7 @@ Excluding feature bug fixes.
[Bug #17423]: https://bugs.ruby-lang.org/issues/17423
[Feature #17479]: https://bugs.ruby-lang.org/issues/17479
[Feature #17490]: https://bugs.ruby-lang.org/issues/17490
+[Feature #17724]: https://bugs.ruby-lang.org/issues/17724
[Feature #17744]: https://bugs.ruby-lang.org/issues/17744
[Feature #17762]: https://bugs.ruby-lang.org/issues/17762
[Bug #18003]: https://bugs.ruby-lang.org/issues/18003
diff --git a/compile.c b/compile.c
index a7862194c09..38a96f165ec 100644
--- a/compile.c
+++ b/compile.c
@@ -6462,6 +6462,9 @@ iseq_compile_pattern_each(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *c
case NODE_CONST:
case NODE_LVAR:
case NODE_DVAR:
+ case NODE_IVAR:
+ case NODE_CVAR:
+ case NODE_GVAR:
case NODE_TRUE:
case NODE_FALSE:
case NODE_SELF:
diff --git a/doc/syntax/pattern_matching.rdoc b/doc/syntax/pattern_matching.rdoc
index 69756369fb5..49835def224 100644
--- a/doc/syntax/pattern_matching.rdoc
+++ b/doc/syntax/pattern_matching.rdoc
@@ -312,6 +312,33 @@ One important usage of variable pinning is specifying that the same value should
end
#=> "not matched"
+In addition to pinning local variables, you can also pin instance, global, and class variables:
+
+ $gvar = 1
+ class A
+ @ivar = 2
+ @@cvar = 3
+ case [1, 2, 3]
+ in ^$gvar, ^@ivar, ^@@cvar
+ "matched"
+ else
+ "not matched"
+ end
+ #=> "matched"
+ end
+
+You can also pin the result of arbitrary expressions using parentheses:
+
+ a = 1
+ b = 2
+ case 3
+ in ^(a + b)
+ "matched"
+ else
+ "not matched"
+ end
+ #=> "matched"
+
== Matching non-primitive objects: +deconstruct+ and +deconstruct_keys+
As already mentioned above, array, find, and hash patterns besides literal arrays and hashes will try to match any object implementing +deconstruct+ (for array/find patterns) or +deconstruct_keys+ (for hash patterns).
@@ -449,7 +476,10 @@ Approximate syntax is:
value_pattern: literal
| Constant
- | ^variable
+ | ^local_variable
+ | ^instance_variable
+ | ^class_variable
+ | ^global_variable
| ^(expression)
variable_pattern: variable
diff --git a/parse.y b/parse.y
index df16cf62365..dec4b7dfd9c 100644
--- a/parse.y
+++ b/parse.y
@@ -1203,7 +1203,7 @@ static int looking_at_eol_p(struct parser_params *p);
%type <id> cname fname op f_rest_arg f_block_arg opt_f_block_arg f_norm_arg f_bad_arg
%type <id> f_kwrest f_label f_arg_asgn call_op call_op2 reswords relop dot_or_colon
%type <id> p_rest p_kwrest p_kwnorest p_any_kwrest p_kw_label
-%type <id> f_no_kwarg f_any_kwrest args_forward excessed_comma
+%type <id> f_no_kwarg f_any_kwrest args_forward excessed_comma nonlocal_var
%type <ctxt> lex_ctxt /* keep <ctxt> in ripper */
%token END_OF_INPUT 0 "end-of-input"
%token <id> '.'
@@ -4517,6 +4517,13 @@ p_var_ref : '^' tIDENTIFIER
/*% %*/
/*% ripper: var_ref!($2) %*/
}
+ | '^' nonlocal_var
+ {
+ /*%%%*/
+ if (!($$ = gettable(p, $2, &@$))) $$ = NEW_BEGIN(0, &@$);
+ /*% %*/
+ /*% ripper: var_ref!($2) %*/
+ }
;
p_expr_ref : '^' tLPAREN expr_value ')'
@@ -4993,6 +5000,11 @@ simple_numeric : tINTEGER
| tIMAGINARY
;
+nonlocal_var : tIVAR
+ | tGVAR
+ | tCVAR
+ ;
+
user_variable : tIDENTIFIER
| tIVAR
| tGVAR
diff --git a/test/ruby/test_pattern_matching.rb b/test/ruby/test_pattern_matching.rb
index c4945505745..320c2c00c70 100644
--- a/test/ruby/test_pattern_matching.rb
+++ b/test/ruby/test_pattern_matching.rb
@@ -400,6 +400,30 @@ END
a == 0
end
end
+
+ assert_block do
+ @a = /a/
+ case 'abc'
+ in ^@a
+ true
+ end
+ end
+
+ assert_block do
+ @@TestPatternMatching = /a/
+ case 'abc'
+ in ^@@TestPatternMatching
+ true
+ end
+ end
+
+ assert_block do
+ $TestPatternMatching = /a/
+ case 'abc'
+ in ^$TestPatternMatching
+ true
+ end
+ end
end
def test_pin_operator_expr_pattern