R's data.table package extends data.frame:
This report summarizes scanner evidence for Rdatatable/data.table, a R project with 3,927 GitHub stars. SynthScan examined 49,125 lines of code across 195 source files, recording 118 pattern matches distributed across 9 syntactic categories. The legacy adjusted pattern signal is 3.2 (Low pattern signal); it is not an authorship estimate.
Use the findings to ask whether maintainers can explain intent, verify dependencies, simplify unnecessary scaffolding, and focus review effort. Risk Payload v1 adds ownership, supply-chain, over-engineering, and review-effort vectors when available. These are prompts for human verification, not probabilities, security findings, or measured maintenance costs.
Use each vector to guide manual verification of the underlying findings.
Payload schema: 1.0.0 · Engine: 2.0.0 · Scoring: heuristic-density-v1 · Scan date: 2026-10-31.
Can maintainers explain intent, assumptions, and trade-offs? 118 finding(s).
Are imports declared and package/API names verified? 0 finding(s).
Are wrappers, guards, and repeated structures necessary? 0 finding(s).
Which changes need focused human review? 118 finding(s).
This chart tracks the legacy adjusted pattern score across scan runs. Changes can reflect source changes, scan coverage, or detector/scoring versions; they do not measure AI adoption or prove that a team refactored code. Compare runs only when their scoring versions are compatible. The dashed line tracks the raw pattern-hit count.
Groups findings by configured severity weight. Severity is not a confidence estimate, security rating, or proof that a package is missing. Verify imports against the project's manifests and inspect each finding in its local design context.
This horizontal bar chart shows where configured pattern scores accumulate across directories. Treat the bars as locations to inspect, not as evidence of authorship or code quality. Use the file-level findings to decide whether a directory needs a focused ownership, dependency, complexity, or review check.
The scanner identified 118 distinct pattern matches across 9 syntactic categories. Each entry below represents a discrete location in the source code where the engine recorded a detector match to inspect in context. Expand any category row to inspect the individual file paths, line numbers, code snippets, and the lexical context (CODE, COMMENT, or STRING) in which each match was detected.
Reading the findings table: The Severity column indicates the configured finding weight (CRITICAL / HIGH / MEDIUM / LOW). The Context column identifies whether the match occurred inside executable code, an inline comment, or a string literal — legacy comment-context matches receive a ×1.5 score weight. The ⚡ bolt icon marks clustered matches: three or more patterns within a 10-line window, each receiving an additional ×1.5 density multiplier under the legacy scoring model.
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | NEWS.md | 241 | d = data.table(id1=rep(1:2, each=3L), id2=letters[c(4:3,5L,3:5)], v1=1:6) | COMMENT |
| LOW | NEWS.md | 401 | #5: 2025-09-14 5 | COMMENT |
| LOW | NEWS.md | 441 | # user system elapsed | COMMENT |
| LOW | NEWS.md | 641 | # 3: a2 b1 c2 999 999 NaN 3 | COMMENT |
| LOW | NEWS.md | 1161 | # Usage | COMMENT |
| LOW | NEWS.md | 1241 | # <int> <int> <int> | COMMENT |
| LOW | NEWS.md | 1401 | COMMENT | |
| LOW | NEWS.md | 1441 | # was: | COMMENT |
| LOW | NEWS.md | 1461 | COMMENT | |
| LOW | NEWS.md | 1501 | COMMENT | |
| LOW | .ci/.lintr.R | 21 | message = "Use messagef to avoid fragmented translations.", | COMMENT |
| LOW | .ci/atime/tests.R | 41 | dt <- data.table(group = rep(1:2, l=N)) | COMMENT |
| LOW | .ci/atime/tests.R | 61 | # | COMMENT |
| LOW | .ci/atime/tests.R | 81 | # | COMMENT |
| LOW | .ci/atime/tests.R | 161 | #define isFrame(x) isDataFrame(x) | COMMENT |
| LOW | .ci/linters/r/dt_lengths_linter.R | 1 | # This is lintr::lengths_linter(), but including 'vapply_1i()' which is more common internally in data.table | COMMENT |
| LOW | R/duplicated.R | 41 | f = attr(o, "starts", exact=TRUE) | COMMENT |
| LOW | R/duplicated.R | 61 | # H = 1:2e8, | COMMENT |
| LOW | R/test.data.table.R | 161 | # runtime test number (i.e. 'numStr') since we're just doing a static check here, though we _are_ careful to match | COMMENT |
| LOW | R/test.data.table.R | 181 | on=c(id='call_id')] | COMMENT |
| LOW | R/test.data.table.R | 441 | } | COMMENT |
| LOW | R/data.table.R | 21 | COMMENT | |
| LOW | R/data.table.R | 141 | } | COMMENT |
| LOW | R/data.table.R | 221 | # (1) lapply(.SD, ...) | COMMENT |
| LOW | R/data.table.R | 641 | # exclude '..1' etc. for #5460 | COMMENT |
| LOW | R/data.table.R | 2281 | if (length(expr)==3L && .arg_is_narm(expr)) | COMMENT |
| LOW | R/data.table.R | 2861 | .Call(Cselfrefokwrapper,DT,verbose) | COMMENT |
| LOW | R/data.table.R | 3521 | ## Additional restrictions are imposed if x is .SD, or if options indicate that no optimization | COMMENT |
| LOW | R/foverlaps.R | 201 | COMMENT | |
| LOW | R/foverlaps.R | 221 | # distinguishable representative number*!!! In case of integers, the next integer after 5L is 6L. Simple. Increment is 1 | COMMENT |
| LOW | R/foverlaps.R | 241 | # --- | COMMENT |
| LOW | R/cedta.R | 1 | cedta.pkgEvalsUserCode = c("gWidgetsWWW","statET","FastRWeb","slidify","rmarkdown","knitr","ezknitr","IRkernel", "rtvs") | COMMENT |
| LOW | .dev/revdep.R | 1 | # Run by package maintainer via aliases revdepsh and revdepr in .dev/.bash_aliases. See | COMMENT |
| LOW | .dev/revdep.R | 81 | require(utils) # only base is loaded when R_PROFILE_USER runs | COMMENT |
| LOW | .dev/cc.R | 1 | # data.table dev | COMMENT |
| LOW | .github/workflows/rchk.yaml | 1 | # adapted from a similar check run by {arrow} | COMMENT |
| LOW | src/forder.c | 701 | // several columns could squash into 1 byte. due to this bit squashing is why we deal | COMMENT |
| LOW | src/forder.c | 921 | // insert sort with some twists: | COMMENT |
| LOW | src/forder.c | 1341 | } | COMMENT |
| LOW | src/inrange.c | 21 | // while (i < n) { | COMMENT |
| LOW | src/fread.h | 1 | #ifndef dt_FREAD_H | COMMENT |
| LOW | src/fread.h | 81 | // Maximum number of rows to read, or INT64_MAX to read the entire dataset. | COMMENT |
| LOW | src/fread.h | 101 | // always at least 1). | COMMENT |
| LOW | src/fread.h | 121 | // Character that marks the beginning of a comment. When '\0', comment | COMMENT |
| LOW | src/fread.h | 141 | COMMENT | |
| LOW | src/myomp.h | 1 | COMMENT | |
| LOW | src/myomp.h | 21 | #define omp_get_num_threads() 1 | COMMENT |
| LOW | src/dogroups.c | 1 | #include "data.table.h" | COMMENT |
| LOW | src/dogroups.c | 21 | // x y | COMMENT |
| LOW | src/dogroups.c | 541 | // user system elapsed | COMMENT |
| LOW | src/dogroups.c | 561 | // old code - no changes, R v3.1.0 --- BUT RESULTS ARE WRONG! | COMMENT |
| LOW | src/fwriteR.c | 1 | #include <stdbool.h> | COMMENT |
| LOW | src/ijoin.c | 641 | // k = from[i]; | COMMENT |
| LOW | src/data.table.h | 1 | #include "myomp.h" // first for clang-13-omp, #5122 | COMMENT |
| LOW | src/data.table.h | 21 | #endif | COMMENT |
| LOW | src/data.table.h | 41 | #define IS_UTF8(x) (getCharCE(x) == CE_UTF8) | COMMENT |
| LOW | src/data.table.h | 61 | # undef MAX | COMMENT |
| LOW | src/data.table.h | 81 | #define NEED2UTF8(s) !(IS_ASCII(s) || (s)==NA_STRING || IS_UTF8(s)) | COMMENT |
| LOW | src/freadR.h | 1 | #ifndef dt_FREAD_R_H | COMMENT |
| LOW | src/fsort.c | 281 | COMMENT | |
| 27 more matches not shown… | ||||
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| MEDIUM | .gitlab-ci.yml | 103 | ## most comprehensive tests | COMMENT |
| MEDIUM | .ci/atime/tests.R | 52 | # See documentation in https://github.com/Rdatatable/data.table/wiki/Performance-testing for best practices. | COMMENT |
| MEDIUM | .ci/atime/tests.R | 80 | # A function to customize R package metadata and source files to facilitate version-specific installation and testing. | COMMENT |
| LOW | R/fread.R | 219 | # not worth doing a behavior test here, so just use getRversion(). | COMMENT |
| LOW | R/duplicated.R | 74 | ## unique.data.table has been refactored to simply call duplicated.data.table | COMMENT |
| LOW | R/wrappers.R | 2 | # Very small (e.g. one line) R functions that just call C. | COMMENT |
| LOW | R/data.table.R | 2008 | # TO DO: combine uniqlist and uniquelengths into one call. Or, just set len__ to NULL when dogroups infers that | COMMENT |
| MEDIUM | R/data.table.R | 3434 | # is robust to unnamed expr. Note that NA names are not possible here. | COMMENT |
| LOW | R/foverlaps.R | 209 | # Firstly, assuming 64-bit precision, we can't simply add 1L. For e.g., consider: | COMMENT |
| LOW | R/fcast.R | 136 | # just use the last column (as guess(data) would do) because length will be | COMMENT |
| MEDIUM | src/snprintf.c | 36 | // loop here with more robust checks as well to catch mistakes in fmt | COMMENT |
| MEDIUM | src/utils.c | 25 | // which needed a repeat of the argument. Hence simpler and more robust to return false when not type double. | COMMENT |
| MEDIUM | src/openmp-utils.c | 69 | // Keep this light, simple and robust. initDTthreads() ensures 1 <= DTthreads <= omp_get_num_proc() | COMMENT |
| MEDIUM | src/openmp-utils.c | 140 | // Allows robust testing of environment variables using Sys.setenv() to experiment. | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | R/fread.R | 98 | # Check if input is a connection and read it into memory | COMMENT |
| LOW | R/test.data.table.R | 373 | # Check if UTF-8 symbols can be represented in native encoding | COMMENT |
| LOW | R/test.data.table.R | 393 | # Check if y was explicitly provided (not just the default) | COMMENT |
| LOW | R/data.table.R | 329 | # Return result | COMMENT |
| LOW | .dev/cc.R | 50 | # Assign directly to better imitate actual namespace imports. Earlier tried to require(include.only=) these objects, | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW⚡ | R/data.table.R | 508 | # Step 1: Apply lapply(.SD) optimization | COMMENT |
| LOW⚡ | R/data.table.R | 513 | # Step 2: Apply GForce optimization | COMMENT |
| LOW⚡ | R/data.table.R | 518 | # Step 3: Apply old mean optimization (fallback when GForce is not used) | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW⚡ | R/data.table.R | 508 | # Step 1: Apply lapply(.SD) optimization | COMMENT |
| LOW⚡ | R/data.table.R | 513 | # Step 2: Apply GForce optimization | COMMENT |
| LOW⚡ | R/data.table.R | 518 | # Step 3: Apply old mean optimization (fallback when GForce is not used) | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| HIGH | NEWS.1.md | 1540 | 1. It seems OpenMP is not available on CRAN's Mac platform; NOTEs appeared in [CRAN checks](https://cran.r-project.org/w | CODE |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | R/data.table.R | 941 | # TODO: implement better version of "any"/"all"/"which" to avoid | COMMENT |
| LOW | R/setkey.R | 219 | # TODO: implement integer and character in Cfsort and remove this branch and warning | COMMENT |
| LOW | src/ijoin.c | 8 | // TODO: implement 'lookup' for 'gaps' and 'overlaps' arguments | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| MEDIUM | R/IDateTime.R | 257 | # This method is just for ggplot2, #1713 | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | R/test.data.table.R | 443 | # Usage: | COMMENT |