find_tool

Rejuvenation Find

Find matches of the given code snippet in your project.

We will refer to the given code snippet as the find pattern.

Find matches code based on their AST. So it is independent of layout and presence of comment.

placeholders

There are two types of placeholders, those starting with "$S_" and those starting with "$M_". Any alphanumeric string is allowed to follow after those prefixes.

"$S_" placeholders allow one to match a single AST node, be that a single expression, a single statement, a single argument, or anything else. As long as Ada parses it to a single AST node, the "$S_" placeholders can match it.

"$M_" placeholders allow one to match a list of AST nodes, i.e., zero or more nodes.

placeholders in find patterns

A find pattern might contain multiple different placeholders.

A find pattern might contain the same placeholder multiple times. This add a constraint to the find process: A match will only be found when all occurrence of the same placeholder are identical. Note that universities are still researching what the best definition of identical is. In analogy with Regular Expressions, the term backreference is used to denote a placeholder that reoccurs.

Examples

Double Negation

Find pattern for double negation

not (not $S_Condition)

Type Definition

Find type definitions for access to procedures with a single parameter of type Integer.

type $S_P is access procedure ($S_I : Integer);

For All

Ada 2012 has quantified expressions.

Find pattern for code that is equivalent to returning a for all expression

for $S_Element of $S_Elements loop 
    if $S_Condition then return false; end if; 
end loop;
return true;

Identical tail statement

Find pattern for if statement with an identical tail statement in the then- and else-branch.

   if $S_Cond then 
       $M_Stmts_True; $S_Tail;
   else 
       $M_Stmts_False; $S_Tail;
   end if;