Easytrieve Function Cheat Sheet

Invocation Pattern

Functions take arguments in parentheses. Arguments may be fields, literals, or nested expressions. Result type must fit target field in assignment. Mismatch causes compile diagnostics or truncation. Some functions are niladic—no arguments—like current date helpers referencing system context.

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WS-TODAY = DATE-FUNCTION()
IF ABS(VAR-A - VAR-B) GT TOLERANCE
   DISPLAY 'VARIANCE'
END-IF
WS-EDITED = EDIT(NUM-FIELD, 'ZZ,ZZ9.99')

String Functions

String functions manipulate alphanumeric fields—length, trim, scan, substring where available. Classic Easytrieve without rich builtins uses DEFINE overlay subfields and INDEX loops; modern Plus catalogs add more direct calls. Always check length limits—eight-character targets truncate.

Date and Time Functions

Date functions support report headers, age calculations, and period filters. SYSDATE system field often supplements functions for current date. Packed and display date formats need consistent masks—document internal format in comments. Calendar edge cases (leap year, month-end) deserve unit tests on test LPAR.

Numeric and Math Functions

Conversion and Formatting

Conversion changes representation—numeric to character, packed to zoned. Formatting applies EDIT masks for human-readable output without changing stored value semantics. Report LINE masks overlap formatting functions—choose one consistent approach per program.

Testing Functions

File and System Functions

Report Functions

Report writer may expose functions for page number, line count, or break level in TITLE and LINE expressions—consult report functions tutorial. Mixing report functions with batch FILE logic in same PROC requires knowing when report engine context is active.

Category Index Links

Fallback When Function Missing

1. Check Application Reference for alternate name or macro.
2. Use PROC loop with INDEX for string scan.
3. Use DEFINE overlay for substring extract.
4. Use EDIT masks on REPORT LINE for display.
5. CALL external routine if policy allows.

Common Function Mistakes

• Assuming Plus catalog on Report Generator compile.
• Wrong argument type—alpha where numeric required.
• Ignoring truncated assignment target length.
• Date format mismatch between function result and compare field.
• Using function where statement required or vice versa.

Explain It Like I'm Five

Functions are mini-calculators inside your sentence. Instead of writing ten steps to get today's date on the report, a date function gives you the date in one piece. The cheat sheet lists which calculators exist for strings, numbers, and dates—your school may have a smaller calculator than another school, so try on your computer before the big test.

Exercises

1. Write assignment using ABS on variance field pseudocode.
2. Pick category for formatting dollar amounts on report.
3. Document pilot compile steps for one undocumented function name.
4. Describe overlay fallback for substring when SUBSTR absent.
5. Map five tasks to function categories from this sheet.