sas94

When to Use

Activate this skill when the user asks to:

• Write, review, or modify any .sas file
• Translate a study description into a SAS 9.4 program (DATA step, PROC SQL, macros)
• Debug a SAS program producing unexpected results, log errors, warnings, or NOTE-level diagnostics
• Build or repair a macro: %macro scope, %let, %sysfunc, quoting (%str, %nrstr, %bquote, %superq), &&var, call symput, symget()
• Author DATA step logic with MERGE/BY, first./last., retain, arrays, hash objects, PDV reasoning
• Write or audit PROC SQL (joins, dedup, INTO :macvar, RESET)
• Run base procs (FREQ, MEANS, UNIVARIATE, SORT, TRANSPOSE, REPORT) or statistical procs (LOGISTIC, GLM, MIXED, GENMOD, SURVEY*, LIFETEST)
• Capture proc output via ODS (RTF, EXCEL, PDF, ODS OUTPUT, ODS GRAPHICS, GTL)
• Build PROC FORMAT value/picture formats, or use date/time functions and input()/put() conversions
• Look up SAS function signatures (date arithmetic, string manipulation, numeric)

Prefer this skill whenever the current file or referenced path is a .sas file, or when the user references SAS 9.4 code (DATA step, PROC SQL, %macro, ODS, hash tables, etc.).

When NOT to Use

Skip even if keywords overlap — another skill or a generic response fits:

• R (dplyr, tidyverse, data.frame)
• Python (pandas, dataframe)
• Stata, SPSS
• Generic SQL (T-SQL, PostgreSQL, BigQuery)
• Procfile or shell "proc" commands
• Git merges — even when the user says "merge", "array", "dataframe", or "proc"

Critical Rules (Summary)

Top-20 aggregated rules (macros + DATA step + GWU items) live in references/sas-master-reference.md; per-topic rules live in the matching topic file. Consult the routing table below and load the relevant reference file before writing or reviewing SAS code. Do not attempt to answer SAS questions from SKILL.md alone.

STOP and Re-check — Known Silent-Failure Patterns

Stop and load the indicated reference file before writing or reviewing code when you see any of these patterns. Each pattern is a documented SAS footgun that compiles or runs cleanly but produces wrong results or bypasses a guardrail.

• data a; set b; a = b + c; run; without retain — STOP. First row writes an uninitialized accumulator. Load references/data-step.md for retain-behavior and PDV-initialization rules.
• %macro foo; ... %mend; missing () in the macro signature — STOP. sasjs/lint hasMacroParentheses forbids this; silent-parameter bugs follow. Load references/macros.md.
• proc sql; create table t as select * from a, b; (unqualified comma join) — STOP. This is a cartesian product, not a join. Load references/proc-sql.md.
• merge a b; by id; run; without handling first./last. — STOP. Right-table values silently overwrite left-table values on duplicate keys. Load references/data-step.md MERGE/BY rules.
• declare hash h(); h.definekey(); h.definedata(); h.definedone(); without length declared for key/data vars upstream — STOP. Hash vars inherit PDV length; undeclared → truncation. Load references/hash-tables.md.
• %let x = &y; inside %macro without scope audit — STOP. Implicit global-scope write when y resolves at outer scope. Load references/macros.md scope-and-quoting rules.

Reference Routing

Load the appropriate reference file based on the task or trigger phrase. This is the authoritative routing table for the skill.

Task / Trigger Phrase	Load Reference	Also Load If
New .sas file, study program skeleton	sas-master-reference.md	+ domain file per section
"MERGE", "BY processing", "first.", "last.", "retain", "array", "PDV"	data-step.md	functions-dates.md / functions-strings.md / functions-numeric.md if fns involved
"PROC SQL", "join claims", "dedup", "INTO :macvar"	proc-sql.md	macros.md if INTO drives macro
"%macro", "%let", "%sysfunc", quoting error, &&var, symget/symput	macros.md	sas-master-reference.md for scope rules
PROC FREQ / MEANS / UNIVARIATE / SORT / TRANSPOSE / REPORT	base-procs.md	ods-and-output.md if capturing output
PROC LOGISTIC / GLM / MIXED / GENMOD / SURVEY* / LIFETEST	stat-procs.md	ods-and-output.md for ODS OUTPUT
"hash join", "hash lookup", declare hash, definekey, hashiter	hash-tables.md	data-step.md for DATA-step context
ODS RTF/EXCEL/PDF, ODS OUTPUT, ODS GRAPHICS, GTL	ods-and-output.md	stat-procs.md if capturing proc output
PROC FORMAT, date/time fns, picture formats, input()/put()	formats-informats.md	functions-dates.md
"INTNX", "INTCK", "date arithmetic", "TODAY", "MDY", "DATEPART", "YEAR"/"MONTH"/"DAY"	functions-dates.md	formats-informats.md for PUT / INPUT around dates
"SCAN", "SUBSTR", "CATX", "CATS", "COMPRESS", "TRANWRD", "INDEX", "FIND", string parsing	functions-strings.md	macros.md for %SCAN / %SUBSTR / quoting
"ROUND", "MOD", "SUM function", "MEAN" (row-wise), "DIM", "HBOUND", "LBOUND", array inspection	functions-numeric.md	base-procs.md for PROC MEANS column aggregates
Unknown/novel, "how do SAS programmers do X"	idioms-from-lexjansen.md	+ best-match topic file

Assets

Use these templates as starting points — they supply header comment blocks, not logic. Fill in body idioms by loading the relevant reference file per the routing table above.

• assets/data-step-template.sas — generic DATA step skeleton
• assets/proc-sql-template.sas — PROC SQL skeleton
• assets/macro-template.sas — %macro / %mend skeleton with parenthesized signature
• assets/analysis-template.sas — end-to-end study-program scaffold

Workflow

1. Identify the trigger (file type, keyword, or explicit request) and match it to a row in the Reference Routing table.
2. Load the indicated reference file — not SKILL.md — before writing or reviewing any non-trivial code.
3. Apply the STOP-and-Re-check patterns above as a pre-flight check for the most common silent-failure classes.
4. For new files, start from the matching assets/*.sas template.
5. When a pattern does not clearly match one reference, start with references/idioms-from-lexjansen.md for real-world idioms, then branch to the topic file.

Shell commands. Skill does not execute SAS. Reference files suggest diagnostic shell commands (hexdump, file) for inspecting .sas bytes — Bash not pre-approved, prompts at project scope.