[justinhwang]

Summary

A tidy of constants.go with no value changes. The file was one flat block, with related declarations also scattered through index.go, hierarchy.go and faceijk.go. It is now one block per concern:

• exported limits and conversions
• degree spans (piDeg, twoPiDeg, halfPiDeg)
• the C library's mathematical constants, with the previously undocumented ones commented
• cell geometry counts
• index digits
• faceNeighbors slot indices
• the index bit layout, now including the offsets and masks that lived in index.go
• table sentinels, now including invalidFace from faceijk.go

Values that restate another are derived from it, or collapsed into one name:

• The digits are the C Direction enum, 0 through 7 in order, so they are an iota sequence ending in numDigits. invalidDigit was the same 7 under another name (the C header defines NUM_DIGITS = INVALID_DIGIT), so there is now one name for the digit count and the unset value of a digit.
• numHexChildren and numPentChildren were also 7 and 6 under other names: one child per valid digit, less the pentagon's deleted K-axis child. fullChildCount in hierarchy.go was their only user and its doc comment already states the two counts, so it returns them directly, as the C code does.
• dirIJ, dirKI, dirJK are iota + 1; slot 0 of faceNeighbors is the face itself.
• twoPiDeg and halfPiDeg derive from piDeg; DegsToRads and RadsToDegs use piDeg too.
• digitMask is 1<<perDigitOffset - 1; h3Init is every digit set to numDigits, 1<<(MaxResolution*perDigitOffset) - 1.
• numCellEdges is numHexVerts, one edge per hexagon vertex.
• maxCellBoundaryVerts duplicated the exported MaxCellBndryVerts and is removed; the doc comment moved to the exported one.
• polyfill.go set a parent's digit to digitMask where it meant the unset digit. Same value, clearer intent.

Test plan

• Every derived constant checked equal to its former literal (h3Init, digitMask, numDigits, degree spans, directions, DegsToRads, RadsToDegs)
• go test ./... green, root and conformance
• golangci-lint run ./... clean

[coveralls]

Coverage Report for CI Build 39823171393

Coverage remained the same at 100.0%

Details

• Coverage remained the same as the base build.
• Patch coverage: 31 of 31 lines across 10 files are fully covered (100%).
• No coverage regressions found.

Uncovered Changes

No uncovered changes found.

Coverage Regressions

No coverage regressions found.

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Coverage Stats

Relevant Lines:	3669
Covered Lines:	3669
Line Coverage:	100.0%
Coverage Strength:	5169754.83 hits per line

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💛 - Coveralls