SCM DSL — Language Specification (v0.2)

1. Overview

SCM (S-expression Configuration Model) is the domain-specific language for defining Runex ontology types, state machines, and reactive actions. It is a strictly case-sensitive language: every identifier — supertag name, action name, machine name, field name — is matched by exact character equality. Case forgiveness is never applied by the runtime; any case-normalization must be done explicitly at value-construction time by the code that bridges two naming conventions.

2. Identifier Case Sensitivity

Identifiers in SCM are case-sensitive. The runtime stores, looks up, and compares every name byte-for-byte without folding, lower-casing, or normalising in any layer:

Layer	Mechanism	Normalisation
Parser (`dsl/parser.py`)	Raw token → `Symbol`	None
Loader (`ontology/loader.py`)	Forms passed verbatim to def objects	None
Store (`store.py`)	SQL `WHERE name=?` (exact)	None
Engine (`ontology/engine.py`)	`dict.get(name)`	None
Reactive bus (`ontology/reactive.py`)	`==` / `in` comparisons	None
Evaluator (`dsl/eval.py`)	`env[name]` dict access	None

This means:

"Proposal" and "proposal" are different supertags.
(action "project_proposal" ...) and (action "project_Proposal" ...) would be different actions. (The convention is to use only the former.)
If a supertag is named "Task", then dispatch("project_task", ...) will fail with an unknown-action error, because the action was defined as "project_task" but the concatenation of "project_" with "Task" produces "project_Task", which is a different identifier.

3. Naming Conventions

3.1 Supertag Names — PascalCase

Supertag names use PascalCase because they appear in user-facing contexts (Obsidian frontmatter type: [[Thought]], CLI output, rich tables):


Proposal   Task   Thought   WorkItem   IngestConnection
OpenLoopProposal   AgentRun   ProjectBinding

3.2 Action Names — snake_case

Action names use snake_case (all lowercase, underscore-separated):


project_proposal   cancel_project   start_task   claim_workitem
approve_proposal   pause_connection   close_sprint

3.3 Machine Names — PascalCase (usually matching supertag)

Machine names conventionally match the supertag they operate on:


(machine "Thought" (supertag "Thought") ...)
(machine "Proposal" (supertag "Proposal") ...)

3.4 Internal Field Names — double-underscore prefixed

Fields with the __ prefix are reserved for engine internals:


__state__Thought   __state__Proposal   __state__WorkItem
__ref__...   __meta__...   _sync_...   _REACTIVE_...

The __state__ field is constructed as f"__state__{machine.name}" (no case transformation — machine name stored verbatim).

3.5 Bridging Conventions

Any code that constructs a snake_case identifier from a PascalCase supertag name must explicitly normalise the case. For example:


# Watcher convention fallback: supertag "Proposal" → action "project_proposal"
action = f"project_{supertag.lower()}"
 
# Vault binding key
bind_key = f"project-{supertag.lower()}-{vault_key}"
 
# Filesystem path segment from supertag
prefix = cmd["supertag"].lower()

The runtime performs no implicit case conversion. The conversion is always explicit at the construction site.

4. Tokens and Literals

Token	Example	Case-sensitive?
Symbol (unquoted name)	`Thought`, `project_task`	Yes
String literal	`"hello"`, `"Thought"`	N/A (literal)
Boolean	`#t`, `#f`	Lowercase only

5. Rationale

Case sensitivity is chosen for three reasons:

Consistency with the host language. Python is case-sensitive. Mixed rules between DSL and host create subtle bugs that are hard to localise.
Preserves expressiveness. Once case-insensitive matching is introduced, the language can never distinguish two identifiers that differ only in case. OpenLoopProposal and Proposal carry semantic distinction in their PascalCase form; the language should not collapse them.
Predictable failure. A case mismatch produces a deterministic KeyError("unknown action: ...") at the exact point of dispatch, rather than silently matching the wrong definition.