L7+L8: CONST named constants + enforced version gate (fixes #110, stacks on #109) - #111
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L7+L8: CONST named constants + enforced version gate (fixes #110, stacks on #109)#111liqdmetal wants to merge 8 commits into
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…F/ELSE/ENDIF
Replaces GOTO-only spaghetti with structured loops and blocks (spec
dero-improvements-agenda.md L1, P0). Halves contract size, cuts the
len(scdata)*1.5 code-size fee term, makes contracts auditable.
New dvm/control_flow.go:
- FOR var = start TO end [STEP step] / NEXT var — counter loop, step
default 1, nested frames via the interpreter's Loops stack
- WHILE expr / WEND — pre-tested loop, jumps back to the WHILE line
- block IF expr THEN ... [ELSE ...] ENDIF — detected as the line ending
in THEN without GOTO (existing single-line IF THEN GOTO untouched)
- LoopFrame stack on DVM_Interpreter for nesting (FOR-in-WHILE verified)
- findMatchingLine scans forward for WEND/ENDIF respecting nesting
Consensus-safety:
- ALL new keywords gated on DVM version >= 10.0.0 (contract must call
version("10.0.0")); pre-fork contracts cannot accidentally use them
- no parser changes — the line-token interpreter dispatches the new
keywords natively
Tests (dvm/control_flow_test.go, 8 cases):
- FOR/NEXT sum(1..5)=15, FOR/STEP 0+2+4=6, WHILE countdown=10 iterations,
block IF/ELSE both branches, IF-no-ELSE fall-through, nested FOR-in-WHILE
total=9, version gate (1.2.3 rejected), no-version gate (0.0.0 rejected)
Full dvm suite green, whole tree builds.
…F/ELSE/ENDIF
Replaces GOTO-only spaghetti with structured loops and blocks (spec
dero-improvements-agenda.md L1, P0). Halves contract size, cuts the
len(scdata)*1.5 code-size fee term, makes contracts auditable.
New dvm/control_flow.go:
- FOR var = start TO end [STEP step] / NEXT var — counter loop, step
default 1, nested frames via the interpreter's Loops stack
- WHILE expr / WEND — pre-tested loop, jumps back to the WHILE line
- block IF expr THEN ... [ELSE ...] ENDIF — detected as the line ending
in THEN without GOTO (existing single-line IF THEN GOTO untouched)
- LoopFrame stack on DVM_Interpreter for nesting (FOR-in-WHILE verified)
- findMatchingLine scans forward for WEND/ENDIF respecting nesting
Consensus-safety:
- ALL new keywords gated on DVM version >= 10.0.0 (contract must call
version("10.0.0")); pre-fork contracts cannot accidentally use them
- no parser changes — the line-token interpreter dispatches natively
Tests (dvm/control_flow_test.go, 8 cases): FOR sum, FOR/STEP, WHILE
countdown, block IF/ELSE, IF-no-ELSE fall-through, nested FOR-in-WHILE,
version gate (1.2.3), no-version gate (0.0.0). All green.
Also carries the build-manifest fix (go.mod/go.sum) for fresh-clone builds.
The second P0 language item (spec dero-improvements-agenda.md L2): internal
subroutines so entrypoints stop re-implementing helpers.
GOSUB <line>: pushes the return address (the line after the GOSUB) onto
the interpreter's CallStack and jumps to <line>.
RETURN: when CallStack is non-empty, pops it and jumps back (subroutine
return — value ignored, subroutines communicate via shared Locals);
otherwise behaves exactly as today (function return). Fully
backward-compatible: existing contracts never push a CallStack.
Gated on DVM version >= 10.0.0 like L1 (contract must call
version("10.0.0")). Nests correctly (GOSUB-in-GOSUB, GOSUB-in-FOR).
Tests (dvm/control_flow_l2_test.go, 5 cases):
- TestL2_Gosub: shared-Locals helper (x*2)
- TestL2_NestedGosub: 1 + 10 = 11 via nested calls
- TestL2_GosubInFor: helper inside FOR body, 1+2+3 = 6
- TestL2_FunctionReturnStillWorks: plain RETURN unaffected
- TestL2_VersionGate: GOSUB at 1.2.3 rejected
Stacks on L1 (feature/dvm-l1-control-flow-pr, PR DEROFDN#101).
First-class array semantics for DVM-BASIC (spec dero-improvements-agenda.md
L3, P1): DIM a(n) AS Uint64|String creates a zero-filled RAM array
(indices 0..n, cap 1024); a[i] reads via the evaluator's new IndexExpr
case; LET a[i] = expr writes (index may be a literal or expression like a
loop variable); arrlen("a") returns the length.
Design:
- Variable gains Array *[]Variable (pointer keeps Variable comparable —
it is used as a map key in RamStore/SC state)
- Arrays are Locals-only: contracts cannot STORE an array (STORE takes
scalars), so nothing touches the serialized SC state — consensus-neutral
- gated >= 10.0.0 like L1/L2 (contract must call version("10.0.0"))
- composes with L1: FOR i = 0 TO n / a[i] = ... / NEXT i
Tests (dvm/control_flow_l3_test.go, 4 cases): array basics (set/read/
arrlen), FOR-loop fill (sum of squares 0..10 = 385), string arrays,
version gate (1.2.3 rejected).
Full dvm suite green. Stacks on L2 (feature/dvm-l2-subroutines, PR DEROFDN#103).
mapkeys() -> String: comma-separated, sorted keys of the contract's state visible during execution (spec dero-improvements-agenda.md L4, P1). The effective key set is the union of: - RamStore: keys loaded from disk (via DiskLoader) during this call - RawKeys: keys written during this call (TX_Storage.RawKeys) Batch/paged contracts can now iterate their stored keys instead of hand-rolling key sets. The comma-separated String is the DVM-friendly return (intrinsics return String/Uint64); contracts split it, and L3 arrays give the next natural return type. Gated >= 10.0.0 like L1/L2/L3. Tests (dvm/control_flow_l4_test.go, 3 cases): key enumeration sorted/complete, batch iteration pattern, version gate (1.2.3 rejected). Full dvm suite green. Stacks on L3 (feature/dvm-l3-arrays, PR DEROFDN#107).
L7 (P2): CONST name = value declares an immutable named constant (uint64
or string literal) in the interpreter's Constants map. The evaluator
resolves identifiers against Constants first; LET on a constant is
rejected (immutability enforced). Declared inside a function, scoped to
the interpreter run — Locals-only, consensus-neutral.
L8 (P2): the version gate is now the enforced default — every new
syntax keyword (L1-L4, CONST) requires version("10.0.0"); a contract
with no version() call (0.0.0) or an old one (1.2.3) gets a hard
rejection. Pre-fork contracts cannot accidentally use new syntax.
Tests (dvm/control_flow_l7_test.go, 5 cases): CONST uint arithmetic
(BASE*SCALE+1=301), CONST string concat+compare, CONST immutability
(LET rejected), version gate (1.2.3), no-version gate (0.0.0).
Full dvm suite green (25 control-flow tests incl. L1-L4 regression).
Stacks on L4 (feature/dvm-l4-mapkeys, PR DEROFDN#109).
This was referenced Aug 23, 2026
Pinned by TestWargameL7ConstImmutable + TestWargameL7ConstCaseVariant: - LET on a declared CONST is rejected (immutability enforced) - CONST FOO cannot be shadowed by a case-variant LET foo (the DIM foo + LET foo path stays distinct from CONST FOO; the constant's value is preserved) No bug found — the L7+L8 CONST implementation holds under attack. Tests document the boundary for future changes.
Author
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Superseded by PR #126 — the consolidated language package. Same code, one reviewable PR with no vendor noise. |
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Summary
L7 + L8 from the DVM-BASIC language agenda (P2): named immutable constants (
CONST) and the version auto-gate enforced as the default.L7:
CONSTConstantsfirstLETon a constant is rejectedL8: version auto-gate
Every new syntax keyword (L1 control flow, L2 subroutines, L3 arrays, L4 mapkeys, L7 CONST) requires
version("10.0.0"). A contract with noversion()call (defaults to 0.0.0) or an old one (1.2.3) gets a hard rejection. Pre-fork contracts cannot accidentally use new syntax — the gate is now the enforced default, not an afterthought.Tests (
dvm/control_flow_l7_test.go, 5 cases)TestL7_ConstUintTestL7_ConstStringTestL7_ConstImmutableTestL8_VersionGateTestL8_NoVersionFull dvm suite green (25 control-flow tests including L1–L4 regression).
Relationship
>= 10.0.0gateBranch:
feature/dvm-l7-l8-const-versionin the forkliqdmetal/derohe-improvements-by-liqdmetal(stacked onfeature/dvm-l4-mapkeys).