Add matching-brackets exercise

exercises/practice/matching-brackets/.meta/matching_brackets.example.pl

@@ -0,0 +1,18 @@
+:- use_module(library(dcg/basics)).
+
+parentheses --> "(", balanced, ")".
+brackets    --> "[", balanced, "]".
+braces      --> "{", balanced, "}".
+
+balanced --> parentheses | brackets | braces, balanced.
+balanced --> [].
+
+non_bracket(C) :-
+    string_codes("()[]{}", Codes),
+    \+ member(C, Codes).
+
+paired(String) :-
+    string_codes(String, Codes),
+    exclude(non_bracket, Codes, BracketCodes),
+    phrase(balanced, BracketCodes),
+    !.

exercises/practice/matching-brackets/matching_brackets.pl

@@ -1,13 +1 @@
-paired([], []) :- !.
-paired(['['|Chars], Opened) :- paired(Chars, ['['|Opened]).
-paired([']'|Chars], ['['|Opened]) :- paired(Chars, Opened).
-paired(['('|Chars], Opened) :- paired(Chars, ['('|Opened]).
-paired([')'|Chars], ['('|Opened]) :- paired(Chars, Opened).
-paired(['{'|Chars], Opened) :- paired(Chars, ['{'|Opened]).
-paired(['}'|Chars], ['{'|Opened]) :- paired(Chars, Opened).
-% paired([_|Chars], Opened) :- paired(Chars, Opened).
-
-paired(String) :-
-    string_chars(String, Chars),    
-    paired(Chars, Opened),
-    !.
+paired(String).

exercises/practice/matching-brackets/matching_brackets_tests.plt

@@ -9,61 +9,61 @@ pending :-
     test(paired_square_brackets, condition(true)) :-
         paired("[]").
 
-    test(empty_string, condition(true)) :-
+    test(empty_string, condition(pending)) :-
         paired("").
 
-    test(unpaired_brackets, [fail, condition(true)]) :-
+    test(unpaired_brackets, [fail, condition(pending)]) :-
         paired("[[").
 
-    test(wrong_ordered_brackets, [fail, condition(true)]) :-
+    test(wrong_ordered_brackets, [fail, condition(pending)]) :-
         paired("}{").
 
-    test(wrong_closing_bracket, [fail, condition(true)]) :-
+    test(wrong_closing_bracket, [fail, condition(pending)]) :-
         paired("{]").
 
-    test(paired_with_whitespace, condition(true)) :-
+    test(paired_with_whitespace, condition(pending)) :-
         paired("{ }").
 
-    test(partially_paired_brackets, [fail, condition(true)]) :-
+    test(partially_paired_brackets, [fail, condition(pending)]) :-
         paired("{[])").
 
-    test(simple_nested_brackets, condition(true)) :-
+    test(simple_nested_brackets, condition(pending)) :-
         paired("{[]}").
 
-    test(several_paired_brackets, condition(true)) :-
+    test(several_paired_brackets, condition(pending)) :-
         paired("{}[]").
 
-    test(paired_and_nested_brackets, condition(true)) :-
+    test(paired_and_nested_brackets, condition(pending)) :-
         paired("([{}({}[])])").
 
-    test(unopened_closing_brackets, [fail, condition(true)]) :-
+    test(unopened_closing_brackets, [fail, condition(pending)]) :-
         paired("{[)][]}").
 
-    test(unpaired_and_nested_brackets, [fail, condition(true)]) :-
+    test(unpaired_and_nested_brackets, [fail, condition(pending)]) :-
         paired("([{])").
 
-    test(paired_and_wrong_nested_brackets, [fail, condition(true)]) :-
+    test(paired_and_wrong_nested_brackets, [fail, condition(pending)]) :-
         paired("[({]})").
 
-    test(paired_and_wrong_nested_brackets_but_innermost_are_correct, [fail, condition(true)]) :-
+    test(paired_and_wrong_nested_brackets_but_innermost_are_correct, [fail, condition(pending)]) :-
         paired("[({}])").
 
-    test(paired_and_incomplete_brackets, [fail, condition(true)]) :-
+    test(paired_and_incomplete_brackets, [fail, condition(pending)]) :-
         paired("{}[").
 
-    test(too_many_closing_brackets, [fail, condition(true)]) :-
+    test(too_many_closing_brackets, [fail, condition(pending)]) :-
         paired("[]]").
 
-    test(early_unexpected_brackets, [fail, condition(true)]) :-
+    test(early_unexpected_brackets, [fail, condition(pending)]) :-
         paired(")()").
 
-    test(early_mismatched_brackets, [fail, condition(true)]) :-
+    test(early_mismatched_brackets, [fail, condition(pending)]) :-
         paired("{)()").
 
-    test(math_expression, condition(true)) :-
+    test(math_expression, condition(pending)) :-
         paired("(((185 + 223.85) * 15) - 543)/2").
 
-    test(complex_latex_expression, condition(true)) :-    
-        paired("\\left(\\begin{array}{cc} \\frac{1}{3} & x\\\\ \\mathrm{e}^{x} &... x^2 \\end{array}\\right)")
+    test(complex_latex_expression, condition(pending)) :-
+        paired("\\left(\\begin{array}{cc} \\frac{1}{3} & x\\\\ \\mathrm{e}^{x} &... x^2 \\end{array}\\right)").
 
 :- end_tests(matching_brackets).