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https://github.com/rjNemo/underscore
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Ruidy
bcb4dd1e9d
Add comprehensive documentation for all new functions: - TakeWhile: take elements while predicate is true - DropWhile: drop elements while predicate is true - Scan: running accumulator (prefix scan) - First/FirstN: get first element(s) safely - Init: all but last element - Intersperse: insert separator between elements - Sliding: sliding window views - FoldRight: right-to-left fold/reduce - Tap: side effects without mutation - Transpose: flip matrix rows/columns - Unzip: split tuples into separate slices - ParallelReduce: parallel reduction (experimental) - Replicate: create n copies of a value Each doc includes: - Clear description - Code examples with output - Common use cases - Edge case handling 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <noreply@anthropic.com>
37 lines
901 B
Markdown
37 lines
901 B
Markdown
---
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title: "Scan"
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date: 2025-01-16T00:00:00-00:00
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---
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`Scan` is like Reduce but returns all intermediate accumulator values. Also known as prefix scan or cumulative fold. Useful for tracking running totals, running maximums, or other cumulative operations.
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```go
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package main
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import (
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"fmt"
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u "github.com/rjNemo/underscore"
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)
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func main() {
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// Running sum
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nums := []int{1, 2, 3, 4}
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add := func(acc, n int) int { return acc + n }
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fmt.Println(u.Scan(nums, 0, add)) // [1, 3, 6, 10]
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// Running maximum
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values := []int{3, 1, 4, 1, 5, 9, 2}
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max := func(acc, n int) int {
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if n > acc {
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return n
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}
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return acc
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}
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fmt.Println(u.Scan(values, 0, max)) // [3, 3, 4, 4, 5, 9, 9]
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// String concatenation
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words := []string{"hello", "world", "!"}
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concat := func(acc, s string) string { return acc + s }
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fmt.Println(u.Scan(words, "", concat)) // ["hello", "helloworld", "helloworld!"]
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}
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```
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