OPM Flow VS Code Extension

Language support for OPM Flow reservoir simulation deck files, with syntax highlighting and development features backed by the full OPM Flow reference manual.

Keyword data is built from OPM/opm-reference-manual at commit 85395fc0.

Features

Syntax Highlighting

Provides syntax highlighting for OPM Flow simulation deck files with support for:

• Section headers: RUNSPEC, GRID, EDIT, PROPS, REGIONS, SOLUTION, SUMMARY, SCHEDULE — scoped so most themes render them in a distinct color (yellow in Dark+)
• Keywords: ALL_CAPS identifiers (e.g., COMPDAT, WELSPECS, DATES)
• Comments: Lines starting with --
• Record terminators: / marking the end of a record
• Numbers: Integers and floating-point values
• Defaults / repeat markers: 1*, 3*, etc. (distinct from ordinary numbers)
• Strings: Text in single quotes
• Template variables: <NAME> placeholders used in macro/ERT workflows
• END keyword: Specially highlighted file terminator

Keyword Autocompletion

Autocomplete support for OPM Flow keywords extracted from the reference manual. Each completion item shows the deck section(s) the keyword is valid in (RUNSPEC, GRID, SCHEDULE, …) and a one-line summary in the documentation pane. Keywords that are valid in every section (e.g. INCLUDE, ECHO) list them all. Completions are triggered when typing uppercase letters at the start of a line.

Parameter Value Completion

Inside a record, when the parameter at the current column has a known set of string options, the suggestion list shows them with a one-line description per option. For example, on a COMPDAT record the STATUS column offers OPEN, SHUT, and AUTO. Multi-record keywords resolve the parameter against the record the cursor is in, so each record gets the right option list.

To activate the list, position the cursor in the parameter column and either start typing an uppercase letter (e.g. O for OPEN) or press Ctrl+Space (Cmd+Space on macOS) to open the suggestions manually. Selecting an option inserts the value quoted, e.g. 'OPEN'.

Hover Tooltips

Hover over any keyword to see a quick tooltip with:

• The keyword name and all valid sections
• A summary from the reference manual
• A parameter table listing all record fields with units and defaults
• A usage example

Hovering over a value in a data record shows the description for that specific parameter column. For example, hovering over the group name in a WELSPECS record shows the GRPNAME parameter description, units, and default.

Keywords on the diagnostics exclusion list (see opm-flow.diagnostics.excludedKeywords under Settings) carry an extra notice in the hover indicating that arity, terminator, and section checks are skipped — useful when squiggles are deliberately suppressed for a keyword.

Diagnostics

Squiggles in the editor catch the most common deck-shape mistakes:

• Unrecognised keyword — a keyword-shaped line whose token isn't in the OPM Flow vocabulary (typo of an identifier, or a custom keyword the parser won't accept).
• Wrong section — a keyword used outside the section(s) it's valid in, e.g. WELSPECS placed in RUNSPEC instead of SCHEDULE. The hover lists the sections where it is valid.
• Over-arity record — a record with more values than the keyword's per-record item count from the OPM Flow parser. Trailing defaults (auto-defaulted by /) are not flagged. The squiggle starts at the first offending value, including N* repeat tokens.
• Missing per-record / — a record line carrying values but no closing /, on keywords known to take records.
• Missing closing / on record-list blocks — keywords like WELSPECS, COMPDAT, WCONHIST that expect the block to end with a standalone / line.
• Missing closing / on array blocks — cell-property arrays like PORO, PERMX, ACTNUM, OPERNUM, ZCORN. The closing / may sit on its own line or trail the last value line — both forms are accepted.
• Indented keyword — a recognised keyword that doesn't start in column 1. Per the OPM Flow reference manual, indented keywords are silently ignored by the simulator.
• Lowercase keyword — a line shaped like a keyword declaration whose upper-cased form is a known keyword. The reference manual states that lowercase keywords produce errors at simulation time.

Keywords whose record bodies don't fit the generic model can be silenced wholesale via the opm-flow.diagnostics.excludedKeywords setting — see Settings below.

Docs Panel (Sidebar)

Open the Explorer sidebar (Ctrl+Shift+E) and scroll down to the OPM Keyword Reference panel. It updates automatically as you move the cursor — no keystrokes needed:

• Cursor on a keyword → full documentation: valid sections, summary, complete parameter table, example
• Cursor on a value column → same view with the matching parameter row highlighted
• Cursor on whitespace or a comment → panel retains the last shown keyword

The panel shows the keyword name, the section(s) it applies to, the summary, the parameter table, and the example. This is the main view for reading long keyword documentation, since it scrolls freely and stays visible while you edit.

Collapse Sections and Keywords

Sections and individual keywords can be folded in the editor gutter. A section runs from a section keyword (RUNSPEC, GRID, EDIT, PROPS, REGIONS, SOLUTION, SUMMARY, SCHEDULE) until the next section keyword, END, or end of file. Individual keyword folds nest inside their section so you can collapse whole sections at once or drill in one keyword at a time.

Align Record Columns

Tidy up record blocks so every column lines up. Invoke OPM Flow: Align Record Columns from the Command Palette or the editor right-click menu. With a selection it aligns only the selected lines; without one it aligns the whole document.

Groups of consecutive record lines (same token count) are reformatted in place: strings left-aligned, integer columns right-aligned, and float columns aligned on the decimal point (integers and N* repeat markers in a float column line up at the decimal point position). Keyword headers, comment lines, the closing /, and trailing -- comments are left untouched.

-- comment lines interspersed within a record group no longer break the group — every data line above and below the comment is aligned against a single shared set of column widths.

If a -- comment line immediately precedes a record group, the columns are aligned to the word positions in that comment, so the data lines up under the headings.

Before:

MULTIPLY
 'PERMZ' 0.2 1 24 1 62 1 1 /
 'PERMZ' 0.04 1 24 1 62 2 2 /
 'PERMZ' 0.016 1 24 1 62 18 18 /
 'PERMZ' 1 1 24 1 62 22 22 /
/

After:

MULTIPLY
 'PERMZ' 0.2   1 24 1 62  1  1 /
 'PERMZ' 0.04  1 24 1 62  2  2 /
 'PERMZ' 0.016 1 24 1 62 18 18 /
 'PERMZ'     1 1 24 1 62 22 22 /
/

Add Column Headers

Invoke OPM Flow: Add Column Headers from the Command Palette or the right-click menu to insert a -- comment above the record group with parameter names taken from the keyword documentation, then align the records to those positions.

If a heading comment already exists it is updated in place. Running the command multiple times is idempotent.

Example — cursor anywhere inside the VFPIDIMS record:

VFPIDIMS
-- MXMFLO MXMTHP MXVFPTAB
      30     20       20 /

INCLUDE File Navigation

Quoted file paths on INCLUDE statements become clickable document links. Hold Ctrl (or Cmd on macOS) and click the path — or right-click and choose Go to Definition — to open the referenced file. Paths are resolved relative to the including file's directory.

INCLUDE
  'grid/PERM.inc' /

Generate Keyword Reference

OPM Flow: Generate Keyword Reference (Command Palette Ctrl+Shift+P) opens a Markdown document listing all keywords grouped by section — useful for uploading as context to an AI chat session.

Settings

Configure via File → Preferences → Settings and search for opm-flow, or edit settings.json directly. All settings are scoped per-resource so you can override them per-workspace or per-folder.

Diagnostics

Completion

Docs sidebar and hover columns

These toggles control which columns appear in the keyword docs sidebar and hover tooltips. Disabling unused columns gives the parameter table more horizontal room in narrow side panels.

Supported File Extensions

The extension activates for the following extensions (case-sensitive on some platforms — both common casings are registered where relevant):

Core deck files: .data, .DATA, .inc, .INC, .include, .sch, .SCH, .schedule, .summary, .grdecl, .GRDECL, .vfp, .VFP, .prop, .Ecl, .ecl.

Section data files (Eclipse/OPM include conventions): .aqucon, .aqunum, .dimens, .eqlnum, .equil, .fault, .fipnum, .multnum, .multregp, .multregt, .nnc, .ntg, .opernum, .perm, .poro, .pvt, .rocknum, .satnum, .sattab, .tabdims, .thpres.

Language ID

The language is registered as opm-flow.

Requirements

• VS Code 1.74.0 or later
• Python 3.10+ with lxml (only required when regenerating the keyword index)

Release Notes

0.6.3

• New diagnostic: keyword not starting in column 1. Per the OPM Flow reference manual, indented keywords are silently ignored by the simulator.
• New diagnostic: keyword in non-uppercase form. Lines shaped like a keyword declaration whose upper-cased form is a recognised keyword are flagged because OPM Flow only accepts uppercase keywords.
• Hover on a keyword that is on the diagnostics exclusion list (opm-flow.diagnostics.excludedKeywords) now shows a notice explaining that arity, terminator, and section checks are skipped for that keyword.
• New opm-flow.completion.stringValueStyle setting controls how STRING-typed parameter values appear in completions: quoted (default), unquoted, or both.
• Free-form text after a record-terminating / is now treated as a trailing comment (the -- prefix is no longer required).
• Bare uppercase identifiers inside an open record block are recognised as unquoted string values rather than flagged as unknown keywords (e.g. an INCLUDE followed by an unquoted path on the next line).

0.6.2

• Multi-record keyword support: hover, docs panel and arity diagnostics resolve the parameter against the record the cursor is in for keywords like WELSEGS, VFPPROD, COMPSEGS, ACTIONX, TUNING.
• Diagnostics extended to flag unknown keywords, missing per-record / terminators, and missing closing / on record-list and array blocks.
• New opm-flow.diagnostics.excludedKeywords setting to silence diagnostics for keywords whose record bodies don't fit the generic model.
• New column-toggle settings (opm-flow.columns.*, opm-flow.units.*) to hide unused columns in the docs sidebar and hover tooltips.
• Keyword data merged from the opm-common submodule, with corrected arity classification.
• Recover keywords with duplicate xml:id from the manual and parse dual-name PVT parameter rows.