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# 13.4.2 Matching Resource Names

The resource lookup algorithm searches a specified resource data base and returns the value for the resource binding whose resource name is the closest match to a given complete resource name and class. The intent of the lookup algorithm is to formalize an intuitive notion of the closest match.

Precedence is given to a match which begins higher in the parent-child contact hierarchy. This allows a resource binding with a partial name to define a resource value shared by all members of a window subtree. For example, suppose the resource database contained the following resource bindings:

Resource Name | Resource Value
--- | ---
`(mail * background)` | `'red`
`(* reply background)` | `'blue`

Suppose an application program searched by using the following complete resource name:

`(mail screen-1 reply background)`

then the closest matching value returned would be `'red`.

Precedence is given to the more specific match. A name match is more specific than a class match. Either a name or class match is more specific than a wildcard match. For example, suppose the resource database contained the following resource bindings:

Resource Name | Resource Value
--- | ---
`(mail * background)` | `'red`
`(mail * fill)` | `'blue`

Suppose an application program searched by using the following complete resource name and complete resource class:

`(mail screen-1 reply background)`
`(application root button fill)`

then the closest matching value returned would be `'red` . However, suppose the resource database contained the following resource bindings:

Resource Name | Resource Value
--- | ---
`(mail * background)` | `'red`
`(mail * button background)` | `'blue`

then the closest matching value returned would be `'blue` .

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