KindScorer

The KindScorer assigns a score to each item based on its ContextKind, using a configurable weight map.

Overview

KindScorer is an absolute scorer — it examines only the item’s kind field. The allItems parameter is ignored. The score is a direct lookup in a weight dictionary: if the item’s kind has a configured weight, that weight is returned; otherwise, the score is 0.0.

Fields Used

Field	Source	Purpose
`kind`	ContextItem	Dictionary lookup key

Default Weights

When no custom weights are provided, the following defaults are used:

ContextKind	Weight
`"SystemPrompt"`	1.0
`"Memory"`	0.8
`"ToolOutput"`	0.6
`"Document"`	0.4
`"Message"`	0.2

These defaults reflect a common heuristic: system prompts and memories are typically more important to preserve than messages.

Algorithm

KIND-SCORE(item, allItems, weights):
    // weights is a map of ContextKind -> float64

    if weights contains item.kind:    // ContextKind equality is case-insensitive (see enumerations.md)
        return weights[item.kind]
    else:
        return 0.0

Case-insensitivity is a property of ContextKind equality as defined in Enumerations, not an ad-hoc behavior of the weight dictionary.

Construction Validation

Custom weight maps MUST be validated at construction time:

Each weight value MUST be non-negative (>= 0.0).
Each weight value MUST be finite (not NaN, not positive/negative infinity).
Weight values are not required to be in [0.0, 1.0] — custom weights may exceed 1.0.

VALIDATE-KIND-WEIGHTS(weights):
    for each (kind, weight) in weights:
        if weight < 0.0:
            ERROR("Weight for kind must be non-negative")
        if weight is not finite:
            ERROR("Weight for kind must be finite")

Edge Cases

Condition	Result
Item’s kind is in the weight map	The corresponding weight value
Item’s kind is not in the weight map	0.0
Custom weight map is empty	All items score 0.0
Custom weight exceeds 1.0	The weight value is returned as-is (no clamping)

Complexity

Time: O(1) per item (hash map lookup).
Space: O(K) where K is the number of configured kinds.

Conformance Notes

ContextKind comparison MUST be case-insensitive using ASCII case folding (see ContextKind). A weight configured for "Message" matches items with kind "message", "MESSAGE", etc.
The default weight map MUST contain exactly the five well-known ContextKind values listed above, with the specified weights. Implementations MAY use a different internal representation (e.g., frozen dictionary, immutable map) but MUST produce the same lookup behavior.
Custom weights are not clamped to [0.0, 1.0]. An implementation using KindScorer with weights > 1.0 should be aware that composite scoring may produce scores outside the conventional range.

Cupel Specification