mirror of
https://github.com/metabarcoding/obitools4.git
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Eric Coissac
8c7017a99d
- Update obioptions.Version from "Release 4.4.29" to "/v/ Release v5" - Update version.txt from 4.29 → .30 (automated by Makefile)
42 lines
1.4 KiB
Markdown
42 lines
1.4 KiB
Markdown
# `obiutils.Abs` — Generic Absolute Value Function
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This package provides a **type-generic utility function** for computing the absolute value of signed numeric types in Go.
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## Function Signature
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```go
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func Abs[T constraints.Signed](x T) T
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```
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- **Generic constraint**: `T` must satisfy `constraints.Signed`, i.e., any signed integer type (`int`, `int8`–`int64`) or floating-point type (via future Go versions supporting floats in `constraints.Signed`).
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- **Input**: A value of type `T`.
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- **Output**: The absolute (non-negative) counterpart, same type as input.
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## Semantics
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- Returns `x` if `x ≥ 0`.
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- Otherwise, returns `-x`, effectively flipping the sign.
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- Handles all signed numeric types uniformly — no need for type-specific overloads.
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## Example Usage
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```go
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absInt := obiutils.Abs(-5) // → 5 (type: int)
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absFloat64 := obiutils.Abs(-3.14) // → 3.14 (type: float64)
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```
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## Design Rationale
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- Leverages Go generics for **reusability** and type safety.
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- Avoids duplication across `AbsInt`, `AbsFloat64`, etc.
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- Follows Go’s standard library conventions (e.g., similar to `math.Abs` but *generic* and not limited to floats).
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## Limitations
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- Does **not** support unsigned types (by design: `constraints.Signed` excludes them).
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- For floating-point special cases (`NaN`, `-0.0`) behavior matches native negation semantics.
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## Dependencies
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- Requires `golang.org/x/exp/constraints` for the generic type constraint.
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