COBOL Language Support enhances the COBOL programming experience on your IDE. The extension leverages the language server protocol to provide autocomplete, syntax highlighting and coloring, and diagnostic features for COBOL code and copybooks. The COBOL Language Support extension can also connect to a mainframe using a Zowe CLI z/OSMF profile to automatically retrieve copybooks used in your programs and store them in your workspace.
COBOL Language Support recognizes files with the extensions .cob and .cbl as COBOL files.
How can we improve COBOL Language Support? Let us know on our Git repository
This extension is a part of the Che4z open-source project. Feel free to contribute right here.
COBOL Language Support is also part of Code4z, an all-round package that offers a modern experience for mainframe application developers, including HLASM Language Support, Explorer for Endevor, Zowe Explorer and Debugger for Mainframe extensions.
- Java version 11 or higher with the PATH variable correctly configured. For more information, see the Java documentation.
- To enable automatic copybook retrieval, the following are required:
- Configured TSO/E address space services, z/OS data set and file REST interface, and z/OS jobs REST interface. For more information, see z/OS Requirements.
- Zowe CLI z/OSMF profile with credentials.
The COBOL Language Support extension is not compatible with other extensions that provide COBOL support. We recommend that you disable all other COBOL-related extensions to ensure that COBOL Language Support functions correctly.
The COBOL Language Support extension only supports IBM Enterprise COBOL. Other versions of COBOL are not supported.
COBOL Language Support provides the following COBOL syntax awareness features:
Autocomplete speeds up the coding process by intuitively suggesting the most likely variables or paragraphs to follow existing code. The extension provides live suggestions while you type for:
- COBOL keywords
- COBOL variables
- COBOL paragraphs
- CICS keywords
- Code Snippets
- Copybook variable and paragraph names
- Names of copybooks that are used in the program
The autocomplete feature is only available in the main COBOL file, not in copybooks.
This feature checks for mistakes and errors in COBOL code. The syntax check feature reviews the whole content of the code and suggests fixes, through syntax and semantic analysis which returns diagnostics on the entire context of the code, not just keywords.
This feature is also enabled for CICS keywords and variables.
The extension enables syntax highlighting for COBOL code.
Contrasting colors are used in displayed code for ease of identifying and distinguishing keywords, variables, and paragraphs.
The extension enables outline view and breadcrumb view, which show the structure of elements within the program and allow easy navigation between them.
Before you write your COBOL code from scratch, search the snippet library for useful templates.
Follow these steps:
- Press
F1to open the command palette. - Type Insert Snippet and press enter.
- Select the snippet that you want to insert.
You can also insert a code snippet by typing the name of the snippet in your code and clicking on the autocomplete text.
The COBOL Language Support extension also supports user snippets. Add your custom snippets to the COBOL.json file in your user snippets folder.
The COBOL Language Support extension supports copybooks used in your source code that are stored in a local folder in your workspace. If your copybooks are stored in mainframe data sets, you can use a Zowe CLI z/OSMF profile to automatically download them from the mainframe to your workspace.
You can use copybooks stored in local folders, mainframe data sets or both. To enable copybook support, you specify the folders and data sets that contain copybooks used in your project in the workspace settings. When a copybook is used in the program, the folders and data sets are searched in the order they are listed for files and members that match the copybook's name. If a copybook with the same file name is located in both a local folder and a mainframe data set, the one in the local folder is used.
Copybook support features are disabled for files stored in the folder .c4z/.extsrcs in your workspace. If you also use the Debugger for Mainframe extension to debug your COBOL programs, you might have some files stored in this folder.
You can store your copybooks locally in folders in your workspace and specify those folder paths in your workspace extension settings. Ensure that the file names of your locally stored copybooks are in upper case, for example BOOK1.CPY and not book1.CPY.
Follow these steps:
- Open the Extensions tab, click the cog icon next to COBOL Language Support and select Extension Settings to open the COBOL Language Support extension settings.
- Switch from User to Workspace.
- Under Paths: Local, specify the paths of the folders containing copybooks. Ensure that you specify relative paths to the workspace root. Absolute paths are not supported.
- Tip: To obtain the relative path of a folder in your workspace, right-click it in the folder tree and select Copy Relative Path.
- The folders are searched in the order they are listed. If two folders contain a copybook with the same file name, the one from the folder higher on the list is used.
- Open a program or project.
Copybook support features are now enabled.
You can also set up automatic copybook retrieval from the mainframe to download copybooks from mainframe data sets to your workspace.
Follow these steps:
- Ensure that you have a Zowe CLI z/OSMF profile configured, with credentials defined.
- Open the Extensions tab, click the cog icon next to COBOL Language Support and select Extension Settings to open the COBOL Language Support extension settings.
- Switch from User to Workspace.
- Under Paths: Dsn, list the names of any number of partitioned data sets on the mainframe to search for copybooks. The data sets are searched in the order they are listed, so if two data sets contain a copybook with the same member name, the one from the data set higher on the list is downloaded.
- Under Profile, enter the name of your Zowe CLI z/OSMF profile.
- Open a program or project.
All copybooks used in the program or project which are not stored locally are downloaded from the mainframe data sets that you specified in step 3.
Copybook support features are now enabled.
Copybooks that you retrieve from mainframe data sets are stored in the .c4z/.copybooks directory within the workspace, which is created automatically.
Because copybooks that are downloaded to the .copybooks folder might change on the mainframe, we recommend that you refresh your copybooks from time to time. To refresh your copybooks, manually delete the .copybooks folder in your workspace. The copybooks are then re-downloaded from the mainframe the next time you open a file that references each copybook.
Copybooks downloaded from the mainframe using an older version of COBOL Language Support might also be found in a .copybooks directory in the workspace root. We recommend that you delete this folder so that all files are downloaded again to the .c4z/.copybooks folder.
The extension includes the following copybook support features:
Syntax and semantic analysis are enabled for keywords, variables, and paragraphs across all copybooks used in the COBOL file, to ensure and maintain compatibility of copybooks called in code.
The semantic analysis feature takes into account COPY REPLACING statements which alter the content of copybooks when checking for errors.
Syntax coloring is automatically enabled for copybook files with the extension .cpy, as long as they are used in the main COBOL file.
The Find All References and Go To Definition functionalities are extended to work for occurrences of copybook names, variables and paragraphs in the main COBOL file.
- Find All References identifies all occurrences of variables and paragraphs from copybooks in the code.
- Go To Definition enables you to right-click on any variable or paragraph to reveal a definition of the element. If the definition is in a copybook, or the name of a copybook, the copybook opens.
- Inbuilt protection against recursive and missing copybooks. If the copybook is missing or contains looping code, an error displays, preventing issues only being discovered when the code is executed.
- Variables and paragraphs are defined across copybooks. This ensures consistency of code, and prevents issues in error diagnostics caused by incorrect variables or paragraphs in code.
- Functionality to skip variable levels when called, reducing call time.