mainframe-planning

Create a comprehensive transformation guide that maps each mainframe dependency to its standard COBOL replacement. This guide is a prerequisite for the actual transformation — DO NOT modify any code, only create the guide. ## Output Format Document each mainframe-specific construct with: 1. **Pattern**: The mainframe construct (e.g., `EXEC CICS READ FILE(...)`) 2. **Replacement**: The standard COBOL equivalent 3. **Error Handling**: How to replicate the mainframe's error behavior - Map CICS RESP/RESP2 codes to FILE STATUS equivalents - Specify which FILE STATUS values to check (e.g., 00=success, 23=not found, 35=file not exists) 4. **Resource Cleanup**: Any cleanup the replacement requires (CICS auto-manages resources; file I/O does not) 5. **Edge Cases**: Behavior differences between mainframe and standard COBOL ## Constructs to Address ### Data Operations (CICS/IMS/VSAM) - READ, WRITE, REWRITE, DELETE operations - STARTBR, READNEXT, READPREV (browse operations) - CICS error handling: HANDLE CONDITION, RESP/RESP2 options - VSAM → sequential or indexed file I/O ### UI/Terminal Operations (BMS maps, screens) - SEND MAP, RECEIVE MAP → these can be MOCKED or stubbed - Screen I/O is not needed for business logic validation - Document how to replace with simple ACCEPT/DISPLAY or test harness stubs - Focus on preserving the data flow, not the UI interaction ### Other Mainframe Constructs - Mainframe data types (COMP-3 packed decimal, etc.) - JCL-embedded constructs - IMS calls (if present) ## Critical Requirements - Every CICS command that can fail MUST have an error handling replacement documented - UI operations should be clearly marked as "mock/stub" so the agent doesn't get stuck on them - Prefer: file-based I/O over mainframe I/O, standard data types over mainframe types ## Common Mappings Reference ### FILE STATUS Codes | Code | Meaning | CICS Equivalent | |------|---------|-----------------| | 00 | Success | Normal completion | | 23 | Record not found | NOTFND condition | | 35 | File does not exist | NOTOPEN condition | | 22 | Duplicate key | DUPREC condition | | 3x | I/O errors | Various IOERR conditions | ### CICS to Standard COBOL | CICS Command | Standard COBOL | |--------------|----------------| | `EXEC CICS READ FILE(...)` | `READ filename INTO...` | | `EXEC CICS WRITE FILE(...)` | `WRITE record-name FROM...` | | `EXEC CICS REWRITE FILE(...)` | `REWRITE record-name FROM...` | | `EXEC CICS DELETE FILE(...)` | `DELETE filename RECORD` | | `EXEC CICS STARTBR FILE(...)` | `START filename KEY...` | | `EXEC CICS READNEXT FILE(...)` | `READ filename NEXT INTO...` |