fix(dncl): treat / and ÷ as integer division#666
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…/int) Background: DNCL is taught alongside Python in 共通テスト curricula where \`/\` is integer division for integer operands. Previously DNCL \`/\` mapped to Ruby's float-returning \`/\`, so \`(hidari + migi) / 2\` produced 4.5 instead of 4 — breaking the canonical binary-search example. scratch-vm cannot be modified; the runtime \`/\` always returns float. Fix this entirely on the conversion layer: - \`.to_i\` now compiles to \`operator_mathop(floor, x)\` (was a no-op \`operator_add(x, 0)\`). The \`@ruby:method:to_i\` comment marker preserves the source method name on round-trip. Legacy projects saved with the old \`operator_add(x, 0) + @ruby:method:to_i\` shape still emit \`.to_i\` via the existing compat path in operators-math-gen.js (one-way migration). - DNCL \`/\` and \`÷\` (and existing \`//\`) all wrap their division as \`(a / b).to_i\` so the runtime truncates via the floor mathop. A new \`wrapIntegerDivisions\` helper walks the converted Ruby line and wraps each top-level \`/\` while skipping operands inside strings, balanced parens, and already-wrapped \`(... / ...).to_i\` shapes. - Ruby → DNCL strips \`(EXPR / EXPR).to_i\` back to \`EXPR / EXPR\` so the \`.to_i\` doesn't surface as redundant \`整数(...)\` in the round-trip. - Drop hardcoded (200, 0) on say/puts comments — the natural-anchor capture from PR #665 places them correctly now. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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🚀 Preview deployed: https://smalruby.jp/smalruby3-editor/fix/dncl-integer-division/ |
The two occurrences of '+ 6' computed offsets past the literal strings ').to_i' (in wrapIntegerDivisions, where the cursor was at ')') and '.to_i' (in stripIntegerDivisionToI, where the cursor was past ')'). Replace both with .length references to the explicit string literals so the intent is obvious.
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May 10, 2026
…ger-division fix(dncl): treat / and ÷ as integer division
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Summary
DNCL の
/と÷を「整数同士の割り算は整数を返す (Ruby/Python の慣習)」に修正します。共通テスト DNCL 例題のようなaida = (hidari + migi) / 2が4.5ではなく4になります。scratch-vm の
/は常に float を返す仕様 (変更不可) なので、変換層で対応します。実装方針 (Issue 議論の E 案)
.to_iのブロックマッピングをoperator_mathop(floor)に変更 (旧:operator_add(x, 0)で truncate せず実質 no-op)。@ruby:method:to_iコメントマーカーで round-trip 時に.floorではなく.to_iとして復元。/と÷を Ruby(a / b).to_iにラップ。新ヘルパーwrapIntegerDivisionsがトップレベル/を検出して括弧バランスを取りながら左右オペランドを特定。(EXPR / EXPR).to_iをEXPR / EXPRに戻す (stripIntegerDivisionToI)。operator_add(x, 0)+@ruby:method:to_i) を読み込み → ブロック→Ruby.to_i(既存 generator で対応)。Ruby.to_i→ 新ブロック (operator_mathop(floor))。一方向 migration。例
aida = (hidari + migi) / 2@aida = ((@hidari + @migi) / 2).to_iaida = (hidari + migi) / 2a = 10 / 3@a = (10 / 3).to_ia = 10 / 3a = b / c * d@a = (@b / @c).to_i * @da = b / c * da = b + c / d@a = @b + (@c / @d).to_ia = b + c / da = Data[i + 1] / 2@a = (@_array_Data_[@i + 1] / 2).to_ia = Data[i + 1] / 2Test plan
operator_divideの親がoperator_mathop(floor)+@ruby:method:to_iに/,÷,//がすべて(a / b).to_iにラップされる.to_iラッパーが除去される🤖 Generated with Claude Code