antonsynd · Oct 22, 2026 · Oct 22, 2026 · Oct 22, 2026 · Oct 22, 2026 · Oct 22, 2026
diff --git a/build_tools/cpython_oracle/ledger.yaml b/build_tools/cpython_oracle/ledger.yaml
@@ -277,6 +277,14 @@ deviations:
   spec_ref: docs/language_specification/function_variadic_arguments.md
   existing_diagnostic: SPY0220
   planned_diagnostic: SPY0472
+- id: identifier-letters-bmp-only
+  category: syntax
+  audience: python
+  severity: error
+  code: SPY0015
+  spec_ref: docs/language_specification/identifiers.md
+  existing_diagnostic: SPY0015
+  planned_diagnostic: null
 - id: identity-with-value-types
   category: operators
   audience: python
@@ -381,6 +389,14 @@ deviations:
   spec_ref: docs/language_specification/function_default_parameters.md
   existing_diagnostic: SPY0433
   planned_diagnostic: null
+- id: leading-zero-decimal-integer
+  category: syntax
+  audience: python
+  severity: none
+  code: null
+  spec_ref: docs/language_specification/integer_literals.md
+  existing_diagnostic: null
+  planned_diagnostic: null
 - id: lru-cache-maxsize-saturates
   category: stdlib
   audience: python

diff --git a/docs/design/gap-discovery-contracts.md b/docs/design/gap-discovery-contracts.md
@@ -39,7 +39,7 @@ source-scan guards run in the regular suite.
 
 Well-guarded classes needing no new mechanism: lambda-boundary parsing (differential parse oracle,
 #1037), unparser fidelity (round-trip property tests), CLR name round-trip (interop sweep + #1040),
-deployment closure (`StandaloneDeploymentTests` for the used stdlib closure; `ReferenceDeploymentMatrixTests` for the user-reference axis it lacked, reference source × route with `--no-deps`, `build` and `project` as the assembly-only controls, #2223).
+deployment closure (`StandaloneDeploymentTests` for the used stdlib closure; `ReferenceDeploymentMatrixTests` for the user-reference axis it lacked, reference source × route × {default, `--no-deps`} over every producing command, #2223; `build` and `project` deploy since #2313 cell 0).
 | Emittable-constant admission (#1762, #1769, #1460) | Every parameter default, decorator argument and module `const` initializer the validator admits is one the emitter prints as a C# constant (`const` / `default`): ONE classifier (`Semantic/Validation/ConstantDefaultClassifier`) with per-site admission tables decides, and `CodeGenInfo.IsCompileTimeConstant` is computed from the same `ModuleConst` table — the emitter re-derives nothing | `ParameterDefaultConstantMatrixTests` (kind × host, every admitted cell an executing program, every refused cell SPY0401, SPY0908 in no cell, totality-anchored) + the `DispatchSiteInventoryTests` row for the classifier switch + `EmitterParameterDefaultSeamConformanceTests` (Roslyn syntax scan of `CodeGen/`: every `WithDefault(` takes `GenerateParameterDefault(...)`; the late-bound `x_lb = null` sentinel is the one non-user default and is admitted by exact shape, not by site; seam and sentinel site counts anchored to literals so an empty scan fails) | none |
 | LiteralString use surface (#1766, #1741) | A `LiteralString` value is a `str` at every value-use route — operators, comparison chains, protocols, truthiness, indexing and slicing, iteration, membership, method dispatch including the static-extension lowering — through ONE `OperandView`; the store seam is untouched (`LiteralString <: str` already) | `LiteralStringSurfaceMatrixTests` (receiver {`str`, `LiteralString`} × operation; the two columns print identical stdout; refusal twin refuses identically; the R-P `x += s` control refuses on the `LiteralString` column only) | none |
 | SemanticType codec totality (#1751) | The warm (`--incremental`) build round-trips every `SemanticType` kind the cold build produced: the serializer registry is total over the concrete subclasses, or names its exclusion with a reason that is itself asserted | `TypeCodecRegistryTotalityTests` (reflection over every concrete `SemanticType`; the exclusion set is asserted equal to `{ConstructorReferenceType}` and its reason — SPY0342 refuses the export at the cold build — is the positive control) + `ColdWarmBuildDifferentialTests` (`LiteralString` signature and `-> Self` programs, cold == warm) | none |

diff --git a/docs/deviations.yaml b/docs/deviations.yaml
@@ -2211,3 +2211,41 @@ deviations:
             t.start()
             t.join()
             print(t.ident > 0)       # True
+
+  - id: leading-zero-decimal-integer
+    code: null
+    category: syntax
+    audience: python
+    severity: none
+    python_behavior: "A decimal integer literal with a leading zero is a SyntaxError: `01`, `0_1` and `007` are `leading zeros in decimal integer literals are not permitted; use an 0o prefix for octal integers`. An all-zero literal (`00`, `0_0`) is accepted."
+    sharpy_behavior: "Leading zeros are digits (C#'s rule — C# accepts `007` as 7): `01` and `0_1` lex as the integer 1 and `007` as 7, silently. An octal literal is `0o7` in both languages, so no Python program changes meaning — a Python refusal becomes a Sharpy acceptance. Ruled R-HT (#2300, P68 numeric twin; DEVIATION-by-default under python-fidelity-scope D5 a); refusing them was rejected."
+    spec_ref: docs/language_specification/integer_literals.md
+    existing_diagnostic: null
+    planned_diagnostic: null
+    example:
+      python: |
+        print(01)        # SyntaxError: leading zeros in decimal integer literals are not permitted; use an 0o prefix for octal integers
+        print(00, 0_0)   # 0 0
+      sharpy: |
+        def main():
+            print(01, 0_1, 007)   # 1 1 7
+            print(00, 0_0)        # 0 0
+
+  - id: identifier-letters-bmp-only
+    code: SPY0015
+    category: syntax
+    audience: python
+    severity: error
+    python_behavior: "An identifier's letters are any Unicode code points with the XID_Start/XID_Continue property, including letters outside the Basic Multilingual Plane: `𝒳 = 1` (U+1D4B3 MATHEMATICAL SCRIPT CAPITAL X) binds `𝒳`."
+    sharpy_behavior: "Identifier letters are the letters of the Basic Multilingual Plane — C#'s identifier alphabet, whose letter test is per UTF-16 code unit (Axiom 1). `été = 1` is an identifier; `𝒳 = 1` is refused with SPY0015 `Unexpected character: '\\uD835'`, the message naming the lone high surrogate of the pair (it prints as U+FFFD `'�'` in a terminal). Ruled R-HW (#2300, P68 record round)."
+    spec_ref: docs/language_specification/identifiers.md
+    existing_diagnostic: SPY0015
+    planned_diagnostic: null
+    example:
+      python: |
+        𝒳 = 1
+        print(𝒳)        # 1
+      sharpy: |
+        def main():
+            𝒳 = 1         # SPY0015: Unexpected character: '�' (the lone high surrogate U+D835)
+        # control — a BMP letter: `été = 1` then `print(été)` prints 1
diff --git a/docs/language_specification/float_literals.md b/docs/language_specification/float_literals.md
@@ -26,6 +26,15 @@ precise = 3.141_592_653
   - `d` or `D` for `float64` (System.Double): `3.14d` (redundant but allowed)
   - `m` or `M` for `decimal` (System.Decimal): `3.14m`
 
+A suffix means the same on every spelling of a float — `.5f` is `0.5f`, and `1e5f` and `1_0.2_5m`
+take it too. The integer suffixes `L`, `u` and `ul` (see [Integer Literals](integer_literals.md))
+belong to integers; on a float literal they are refused (SPY0023), as in C#:
+
+```python
+# x = 3.14L                 # ERROR (SPY0023): Invalid numeric suffix: L (a float literal accepts only the float suffixes f, d and m)
+# y = 1e5u                  # ERROR (SPY0023): Invalid numeric suffix: u (a float literal accepts only the float suffixes f, d and m)
+```
+
 ## Narrowing an Unsuffixed Literal to `float32` or `decimal`
 
 An **unsuffixed** float literal may narrow to `float32` or `decimal` at **every** store
@@ -80,9 +89,34 @@ Two limits:
 - Only a **literal** narrows. A `float64`-typed *expression* or variable still requires an explicit
   cast: `x: float32 = y` is SPY0220 for `y: float`.
 - The value must be within `float32`'s range. `x: float32 = 1e40` is SPY0220, not a silent infinity.
+  The same holds for `decimal`, whose range is about ±7.9e28: `d: decimal = 1e29` is SPY0220.
 
 This is a deliberate divergence from C#, which rejects `float f = 0.1;` outright. Precision loss
 within range is accepted — writing the annotation is taken as asking for it.
 
+## A Literal Must Fit Its Own Type
+
+Whatever its spelling, a float literal must have a finite value in the type it resolves to —
+`float64` unsuffixed, `float32` with `f`, `decimal` with `m`. A literal outside that range is
+refused at compile time with SPY0210, the code an out-of-range integer literal draws, and never
+carried as an infinity. Python reads `1e400` as `inf`; Sharpy refuses it, because a silent infinity
+would flow on through arithmetic.
+
+```python
+def main() -> None:
+    big = 1.7976931348623157e308          # float64's largest value
+    print(big)                            # 1.7976931348623157e+308
+    f = 3.4028235e38f                     # float32's largest value
+    print(f)                              # 3.4028235e+38
+    m = 79228162514264337593543950335m    # decimal's largest value
+    print(m)                              # 79228162514264337593543950335
+    # x = 1e400                           # ERROR (SPY0210): Float literal '1e400' is too large for 'double'
+    # y = 1e39f                           # ERROR (SPY0210): Float literal '1e39' is too large for 'float'
+    # z = 1e29m                           # ERROR (SPY0210): Float literal '1e29' is too large for 'decimal'
+```
+
+A negated literal is checked by its digits, so `-1e400` is refused the same way. A literal too
+small to represent is not out of range: `1e-400` is `0.0`, as in Python.
+
 *Implementation*
 - *✅ Native - Direct mapping to C# float literals with compiler-inserted suffixes.*
diff --git a/docs/language_specification/identifiers.md b/docs/language_specification/identifiers.md
@@ -16,7 +16,10 @@ digit      ::= '0'..'9'
 - Can contain letters, digits, and underscores
 - Case-sensitive: `myVar`, `myvar`, and `MYVAR` are different identifiers
 - Cannot be a keyword
-- Unicode letters are allowed but discouraged for interop
+- Unicode letters are allowed but discouraged for interop. They are the letters of the Basic
+  Multilingual Plane — C#'s identifier alphabet (Axiom 1): `été` is an identifier, while a letter
+  outside the BMP, such as `𝒳` (U+1D4B3), is refused with SPY0015 although Python accepts it
+  (deviation `identifier-letters-bmp-only` in `docs/deviations.yaml`)
 
 ## Examples
 

diff --git a/docs/language_specification/integer_literals.md b/docs/language_specification/integer_literals.md
@@ -12,6 +12,16 @@ million = 1_000_000
 billion = 1_000_000_000
 ```
 
+Leading zeros are digits (C#'s rule): `007` is the decimal integer 7 and `0_1` is 1. Python refuses
+both (`leading zeros in decimal integer literals are not permitted`); an octal literal is spelled
+`0o7` in both languages (deviation `leading-zero-decimal-integer` in `docs/deviations.yaml`).
+
+<!-- spec-sweep: output -->
+```python
+def main():
+    print(007, 0_1, 0o7)   # 7 1 7
+```
+
 ## Type Inference
 
 - Integer literals without a suffix are inferred as `int` (32-bit, `System.Int32`) by default

diff --git a/docs/language_specification/module_system.md b/docs/language_specification/module_system.md
@@ -135,12 +135,13 @@ $ sharpyc project app/app.spyproj
 error[SPY0305]: Assembly not found: /…/libs/Greeter.dll
 ```
 
-Deployment: `compile`, for a `.spy` or a `.spyproj`, and `run` copy every referenced assembly
-beside the output, whether the program uses it or not, together with the dependencies that sit
-beside it. `compile --no-deps` copies none of them (the assembly and its `.deps.json` /
+Deployment: every command that produces an assembly — `build`, `compile` (for a `.spy` or a
+`.spyproj`), `project` and `run` — copies every referenced assembly beside the output, whether the
+program uses it or not, together with `Sharpy.Core.dll`, the standard-library assemblies and the
+dependencies that sit beside each, so the output directory runs with `dotnet`. `--no-deps` on
+`build`, `compile` or `project` copies none of them (the assembly and its `.deps.json` /
 `.runtimeconfig.json` host files are still written), and a `--self-contained` publish carries every
-reference. `build` and `project` write the assembly only, without its references or
-`Sharpy.Core.dll`, so a directory meant to run with `dotnet` comes from `compile`.
+reference.
 
 For example, a library built from `greeter.spy` with
 `sharpyc compile greeter.spy -t library -o libs/Greeter.dll`:

diff --git a/docs/stdlib/random.md b/docs/stdlib/random.md
@@ -12,7 +12,7 @@ import random
 
 Initialize the random number generator with the given seed.
 
-### `random.next_double() -> float`
+### `random.random() -> float`
 
 Return the next random floating point number in the range [0.0, 1.0).
 

diff --git a/docs/stdlib/threading.md b/docs/stdlib/threading.md
@@ -16,12 +16,24 @@ import threading
 
 ### `threading.current_thread() -> Thread`
 
+Return the Thread object of the calling thread: the object `start()` was called
+on, or the main thread. A thread the threading module did not start gets a daemon
+`Dummy-N` thread, which stays in `enumerate()`.
+
 ### `threading.active_count() -> int`
 
+Return the number of Thread objects currently alive: the length of `enumerate()`.
+
 ### `threading.main_thread() -> Thread`
 
+Return the main Thread object, named `MainThread`: the thread that first used the
+threading module, which in a Sharpy program is the thread `main()` runs on.
+
 ### `threading.enumerate() -> list[Thread]`
 
+Return a list of every Thread object currently alive: the main thread, every started
+thread that has not finished, and the dummy threads `current_thread()` created.
+
 ### `threading.lock() -> Lock`
 
 ### `threading.r_lock() -> RLock`

diff --git a/src/Sharpy.Cli.Tests/CliOptionEffectSweepTests.cs b/src/Sharpy.Cli.Tests/CliOptionEffectSweepTests.cs
@@ -303,6 +303,7 @@ internal static System.Collections.Generic.List<string> TotalityFailures(RootCom
         ["build --reference"] = "Sharpy.Cli.Tests.Commands.OptionEffectEvidenceTests.Build_Reference_BindsTheImport",
         ["build --module-path"] = "Sharpy.Cli.Tests.Commands.OptionEffectEvidenceTests.Build_ModulePath_ResolvesAnImport",
         ["build --server"] = "Sharpy.Cli.Tests.E2E.CompileServerE2ETests.Client_FallsBackToInProcess_WhenNoServerIsRunning",
+        ["build --no-deps"] = "Sharpy.Cli.Tests.E2E.ReferenceDeploymentMatrixTests.NoDeps_WritesTheAssemblyOnly",
 
         ["compile@.spy --output"] = "Sharpy.Cli.Tests.Commands.CompileCommandTests.Compile_ValidSource_ProducesDll",
         ["compile@.spyproj --output"] = "Sharpy.Cli.Tests.Commands.GeneratedCSharpLayoutTests.CompileProject_OutputOption_PlacesTheAssemblyAndItsCSharp",
@@ -315,7 +316,7 @@ internal static System.Collections.Generic.List<string> TotalityFailures(RootCom
         ["compile@.spyproj --module-path"] = "Sharpy.Cli.Tests.Commands.CompileOptionEffectTableTests.ModulePath_ResolvesABareReferenceName",
         ["compile@.spy --self-contained"] = "Sharpy.Cli.Tests.E2E.ReferenceDeploymentMatrixTests.SelfContained_Compile_PublishesTheReference",
         ["compile@.spy --no-deps"] = "Sharpy.Cli.Tests.Commands.CompileCommandTests.Compile_NoDeps_SkipsCopyingRuntimeDependencies",
-        ["compile@.spyproj --no-deps"] = "Sharpy.Cli.Tests.E2E.ReferenceDeploymentMatrixTests.Control_TheOptOuts_WriteTheAssemblyOnly",
+        ["compile@.spyproj --no-deps"] = "Sharpy.Cli.Tests.E2E.ReferenceDeploymentMatrixTests.NoDeps_WritesTheAssemblyOnly",
         ["compile@.spyproj --incremental"] = "Sharpy.Cli.Tests.Commands.OptionEffectEvidenceTests.CompileProject_Incremental_WritesTheIncrementalCache",
         ["compile@.spyproj --clean"] = "Sharpy.Cli.Tests.Commands.OptionEffectEvidenceTests.CompileProject_Clean_DeletesBinAndObjFirst",
         ["compile@.spy --emit-csharp"] = "Sharpy.Cli.Tests.Commands.CompileCommandTests.Compile_EmitCSharp_WritesCSharpFileAlongsideDll",
@@ -335,6 +336,7 @@ internal static System.Collections.Generic.List<string> TotalityFailures(RootCom
         ["project --reference"] = "Sharpy.Cli.Tests.E2E.ProjectReferenceOptionTests.AReference_IsHonoured_AndAMissingOneIsSpy0305",
         ["project --module-path"] = "Sharpy.Cli.Tests.E2E.ModuleSearchPathCliTests.ProjectModulePathOption_ReachesImportResolution",
         ["project --incremental"] = "Sharpy.Cli.Tests.Commands.OptionEffectEvidenceTests.Project_Incremental_WritesTheIncrementalCache",
+        ["project --no-deps"] = "Sharpy.Cli.Tests.E2E.ReferenceDeploymentMatrixTests.NoDeps_WritesTheAssemblyOnly",
 
         ["emit csharp --output"] = "Sharpy.Cli.Tests.Commands.EmitCommandTests.CSharp_WritesGeneratedFile",
         ["emit csharp --reference"] = "Sharpy.Cli.Tests.Commands.OptionEffectEvidenceTests.EmitCSharp_Reference_BindsTheImport",