feat(languages): add F5 iRules language support

Add the `Irules` language (an F5 iRules / Tcl-scripting dialect) via the
crates.io-pinned `tree-sitter-irules` =0.1.1 grammar, gated behind a new
`irules` Cargo feature (enabled by `all-languages`). `.irule` / `.irules`.

Wiring & public API:
- enums codegen (Cargo.toml, languages.rs, macros.rs) plus the generated
  src/languages/language_irules.rs; dispatch-coverage guard bumped to 22.
- Re-export IrulesCode / IrulesParser from lib.rs (additive new language,
  minor bump per STABILITY.md); exhaustive big-code-analysis-py LANG arm.

Behaviour:
- Checker / Getter / Alterator impls. `when` / `on` / `trap` event
  handlers and `proc` definitions are function spaces, so per-handler
  metrics are reported (handlers count as functions in nom).
- Real metric impls: ABC, Cognitive, Cyclomatic (dedicated switch/arm
  plus the `and`/`or` keyword operators), Exit (return-by-command-name,
  iRules has no return node), Halstead, LoC, NArgs. The remaining metrics
  use the shared defaults.

Tests & docs:
- Rust-parity per-metric tests, a malformed-input synthetic-Unit-root
  test, a self-contained end-to-end integration test
  (tests/irules_test.rs driving the public analyze() API), and
  cross-language cyclomatic/cognitive parity entries vs Rust/Java/Tcl.
- Supported-languages list, cargo-features table, and CHANGELOG entry.
- HTML report gains an `irules` colour palette entry.

Halstead operand double-count fix: iRules' variable_substitution inner
leaf is the named `Id` (not Tcl's anonymous `Id2`), so every `$var` was
counted twice. get_op_type now excludes `Id` whose parent is a
VariableSubstitution; affected Halstead test values corrected.

.bca-baseline.toml refreshed for the added code's file-level metric
growth (per-function complexity stays within thresholds).

Author: dekobon

.bca-baseline.toml

@@ -23,6 +23,20 @@ for historical reference.
 
 ### Added
 
+- Support for **F5 iRules** source files (`.irule`, `.irules`), a Tcl
+  scripting dialect, via the
+  [`tree-sitter-irules`](https://crates.io/crates/tree-sitter-irules)
+  grammar. Adds the `Irules` `LANG` variant and the `IrulesCode` /
+  `IrulesParser` re-exports, gated behind a new `irules` Cargo feature
+  (enabled by `all-languages`). `when EVENT { … }` event handlers and
+  `proc` definitions are treated as function spaces, so per-handler
+  metrics are reported (the grammar's `on` / `trap` handler nodes are
+  handled defensively but parse as ordinary commands in practice). Real
+  implementations are provided for ABC,
+  cognitive, cyclomatic (including the dedicated `switch`/`switch_arm`
+  node and the `and`/`or` keyword operators), exit, Halstead, LoC, and
+  NArgs; the remaining metrics use the shared defaults. Additive new
+  language — minor bump per [STABILITY.md](./STABILITY.md).
 - Cyclomatic complexity's counting of Rust's `?` operator (the
   `try_expression` grammar node) is now configurable
   ([#409](https://github.com/dekobon/big-code-analysis/issues/409)).

CHANGELOG.md

@@ -46,6 +46,7 @@ tree-sitter-c-sharp = "=0.23.5"
 tree-sitter-elixir = "=0.3.5"
 tree-sitter-go = "=0.25.0"
 dekobon-tree-sitter-groovy = "=0.2.0"
+tree-sitter-irules = "=0.1.1"
 tree-sitter-java = "=0.23.5"
 tree-sitter-javascript = "=0.25.0"
 tree-sitter-kotlin-ng = "1.1.0"
@@ -145,6 +146,7 @@ tree-sitter-c-sharp = { workspace = true, optional = true }
 tree-sitter-elixir = { workspace = true, optional = true }
 tree-sitter-go = { workspace = true, optional = true }
 dekobon-tree-sitter-groovy = { workspace = true, optional = true }
+tree-sitter-irules = { workspace = true, optional = true }
 tree-sitter-java = { workspace = true, optional = true }
 tree-sitter-javascript = { workspace = true, optional = true }
 tree-sitter-kotlin-ng = { workspace = true, optional = true }
@@ -188,6 +190,7 @@ all-languages = [
   "elixir",
   "go",
   "groovy",
+  "irules",
   "java",
   "javascript",
   "kotlin",
@@ -218,6 +221,7 @@ csharp = ["dep:tree-sitter-c-sharp"]
 elixir = ["dep:tree-sitter-elixir"]
 go = ["dep:tree-sitter-go"]
 groovy = ["dep:dekobon-tree-sitter-groovy"]
+irules = ["dep:tree-sitter-irules"]
 java = ["dep:tree-sitter-java"]
 javascript = ["dep:tree-sitter-javascript"]
 kotlin = ["dep:tree-sitter-kotlin-ng"]

Cargo.lock

@@ -13,6 +13,7 @@ This is the list of programming languages parsed by
 - [x] Preproc
 - [x] Go
 - [x] Groovy
+- [x] Irules
 - [x] Java
 - [x] JavaScript
 - [x] Kotlin

Cargo.toml

@@ -45,6 +45,7 @@ per-language pipeline depends on).
 | `elixir`     | `tree-sitter-elixir`                                                           |
 | `go`         | `tree-sitter-go`                                                               |
 | `groovy`     | `dekobon-tree-sitter-groovy`                                                   |
+| `irules`     | `tree-sitter-irules` (F5 iRules, a Tcl dialect)                                |
 | `java`       | `tree-sitter-java`                                                             |
 | `javascript` | `tree-sitter-javascript`                                                       |
 | `kotlin`     | `tree-sitter-kotlin-ng`                                                        |

big-code-analysis-book/src/languages.md

@@ -91,6 +91,7 @@ section.lang-bash{background:rgba(96,128,96,0.08);border-left-color:rgba(96,128,
 section.lang-perl{background:rgba(180,120,60,0.08);border-left-color:rgba(180,120,60,0.55)}\
 section.lang-lua{background:rgba(0,86,180,0.08);border-left-color:rgba(0,86,180,0.55)}\
 section.lang-tcl{background:rgba(160,90,140,0.08);border-left-color:rgba(160,90,140,0.55)}\
+section.lang-irules{background:rgba(200,70,120,0.08);border-left-color:rgba(200,70,120,0.55)}\
 section.lang-ruby{background:rgba(204,52,45,0.08);border-left-color:rgba(204,52,45,0.55)}\
 section.lang-elixir{background:rgba(110,73,153,0.08);border-left-color:rgba(110,73,153,0.55)}\
 section.lang-other{background:rgba(127,127,127,0.06);border-left-color:rgba(127,127,127,0.45)}\
@@ -109,6 +110,7 @@ section.lang-bash{background:rgba(96,128,96,0.18)}\
 section.lang-perl{background:rgba(180,120,60,0.18)}\
 section.lang-lua{background:rgba(0,86,180,0.20)}\
 section.lang-tcl{background:rgba(160,90,140,0.20)}\
+section.lang-irules{background:rgba(200,70,120,0.20)}\
 section.lang-ruby{background:rgba(204,52,45,0.18)}\
 section.lang-elixir{background:rgba(110,73,153,0.20)}\
 section.lang-other{background:rgba(200,200,200,0.10)}\
@@ -156,6 +158,7 @@ const LANGUAGE_PALETTE: &[(&str, &str)] = &[
     ("perl", "perl"),
     ("lua", "lua"),
     ("tcl", "tcl"),
+    ("irules", "irules"),
     ("ruby", "ruby"),
     ("elixir", "elixir"),
 ];

big-code-analysis-book/src/library/cargo-features.md

@@ -7,7 +7,7 @@ expression: out
 <head>
 <meta charset="utf-8">
 <title>Code Quality Metrics Summary — big-code-analysis</title>
-<style>body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;margin:1.5rem;color:#222;background:#fafafa}h1{font-size:1.4rem;margin:0 0 0.5rem}h2{font-size:1.15rem;margin:1.5rem 0 0.5rem;border-bottom:1px solid #ccc;padding-bottom:0.25rem}h3{font-size:1rem;margin:1rem 0 0.4rem;color:#444}section{margin-top:2rem}section.lang-section{padding:0.5rem 1rem;border-radius:4px;border-left:3px solid rgba(127,127,127,0.35)}section.lang-section>h2{margin-top:0.25rem}section.lang-rust{background:rgba(222,128,82,0.08);border-left-color:rgba(222,128,82,0.55)}section.lang-python{background:rgba(58,118,196,0.08);border-left-color:rgba(58,118,196,0.55)}section.lang-javascript{background:rgba(229,202,71,0.10);border-left-color:rgba(229,202,71,0.65)}section.lang-typescript{background:rgba(46,116,194,0.08);border-left-color:rgba(46,116,194,0.55)}section.lang-java{background:rgba(196,69,60,0.08);border-left-color:rgba(196,69,60,0.55)}section.lang-kotlin{background:rgba(193,71,167,0.08);border-left-color:rgba(193,71,167,0.55)}section.lang-go{background:rgba(0,173,181,0.08);border-left-color:rgba(0,173,181,0.55)}section.lang-cpp{background:rgba(120,80,180,0.08);border-left-color:rgba(120,80,180,0.55)}section.lang-csharp{background:rgba(83,150,80,0.08);border-left-color:rgba(83,150,80,0.55)}section.lang-php{background:rgba(98,113,178,0.08);border-left-color:rgba(98,113,178,0.55)}section.lang-bash{background:rgba(96,128,96,0.08);border-left-color:rgba(96,128,96,0.55)}section.lang-perl{background:rgba(180,120,60,0.08);border-left-color:rgba(180,120,60,0.55)}section.lang-lua{background:rgba(0,86,180,0.08);border-left-color:rgba(0,86,180,0.55)}section.lang-tcl{background:rgba(160,90,140,0.08);border-left-color:rgba(160,90,140,0.55)}section.lang-ruby{background:rgba(204,52,45,0.08);border-left-color:rgba(204,52,45,0.55)}section.lang-elixir{background:rgba(110,73,153,0.08);border-left-color:rgba(110,73,153,0.55)}section.lang-other{background:rgba(127,127,127,0.06);border-left-color:rgba(127,127,127,0.45)}@media (prefers-color-scheme:dark){section.lang-rust{background:rgba(222,128,82,0.16)}section.lang-python{background:rgba(58,118,196,0.18)}section.lang-javascript{background:rgba(229,202,71,0.16)}section.lang-typescript{background:rgba(46,116,194,0.18)}section.lang-java{background:rgba(196,69,60,0.18)}section.lang-kotlin{background:rgba(193,71,167,0.18)}section.lang-go{background:rgba(0,173,181,0.18)}section.lang-cpp{background:rgba(120,80,180,0.20)}section.lang-csharp{background:rgba(83,150,80,0.18)}section.lang-php{background:rgba(98,113,178,0.20)}section.lang-bash{background:rgba(96,128,96,0.18)}section.lang-perl{background:rgba(180,120,60,0.18)}section.lang-lua{background:rgba(0,86,180,0.20)}section.lang-tcl{background:rgba(160,90,140,0.20)}section.lang-ruby{background:rgba(204,52,45,0.18)}section.lang-elixir{background:rgba(110,73,153,0.20)}section.lang-other{background:rgba(200,200,200,0.10)}}.summary{font-size:0.9rem;color:#444;margin-bottom:0.5rem}.summary strong{color:#222}.summary p{margin:0.2rem 0}.note{font-size:0.85rem;color:#555;margin:0.4rem 0}ul{margin:0.4rem 0 0.4rem 1.2rem;padding:0}li{margin:0.15rem 0;font-size:0.9rem}table.hotspot{border-collapse:collapse;width:100%;font-size:0.85rem;background:#fff;box-shadow:0 1px 2px rgba(0,0,0,0.06);margin-bottom:0.5rem}table.hotspot th,table.hotspot td{padding:0.4rem 0.6rem;border-bottom:1px solid #e5e5e5;text-align:left;white-space:nowrap}table.hotspot th{background:#f0f0f0;cursor:pointer;user-select:none;font-weight:600}table.hotspot th:hover{background:#e5e5e5}table.hotspot th[aria-sort=ascending]::after{content:" \2191"}table.hotspot th[aria-sort=descending]::after{content:" \2193"}table.hotspot tr:nth-child(even) td{background:#fafafa}table.hotspot td.numeric{text-align:right;font-variant-numeric:tabular-nums}</style>
+<style>body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;margin:1.5rem;color:#222;background:#fafafa}h1{font-size:1.4rem;margin:0 0 0.5rem}h2{font-size:1.15rem;margin:1.5rem 0 0.5rem;border-bottom:1px solid #ccc;padding-bottom:0.25rem}h3{font-size:1rem;margin:1rem 0 0.4rem;color:#444}section{margin-top:2rem}section.lang-section{padding:0.5rem 1rem;border-radius:4px;border-left:3px solid rgba(127,127,127,0.35)}section.lang-section>h2{margin-top:0.25rem}section.lang-rust{background:rgba(222,128,82,0.08);border-left-color:rgba(222,128,82,0.55)}section.lang-python{background:rgba(58,118,196,0.08);border-left-color:rgba(58,118,196,0.55)}section.lang-javascript{background:rgba(229,202,71,0.10);border-left-color:rgba(229,202,71,0.65)}section.lang-typescript{background:rgba(46,116,194,0.08);border-left-color:rgba(46,116,194,0.55)}section.lang-java{background:rgba(196,69,60,0.08);border-left-color:rgba(196,69,60,0.55)}section.lang-kotlin{background:rgba(193,71,167,0.08);border-left-color:rgba(193,71,167,0.55)}section.lang-go{background:rgba(0,173,181,0.08);border-left-color:rgba(0,173,181,0.55)}section.lang-cpp{background:rgba(120,80,180,0.08);border-left-color:rgba(120,80,180,0.55)}section.lang-csharp{background:rgba(83,150,80,0.08);border-left-color:rgba(83,150,80,0.55)}section.lang-php{background:rgba(98,113,178,0.08);border-left-color:rgba(98,113,178,0.55)}section.lang-bash{background:rgba(96,128,96,0.08);border-left-color:rgba(96,128,96,0.55)}section.lang-perl{background:rgba(180,120,60,0.08);border-left-color:rgba(180,120,60,0.55)}section.lang-lua{background:rgba(0,86,180,0.08);border-left-color:rgba(0,86,180,0.55)}section.lang-tcl{background:rgba(160,90,140,0.08);border-left-color:rgba(160,90,140,0.55)}section.lang-irules{background:rgba(200,70,120,0.08);border-left-color:rgba(200,70,120,0.55)}section.lang-ruby{background:rgba(204,52,45,0.08);border-left-color:rgba(204,52,45,0.55)}section.lang-elixir{background:rgba(110,73,153,0.08);border-left-color:rgba(110,73,153,0.55)}section.lang-other{background:rgba(127,127,127,0.06);border-left-color:rgba(127,127,127,0.45)}@media (prefers-color-scheme:dark){section.lang-rust{background:rgba(222,128,82,0.16)}section.lang-python{background:rgba(58,118,196,0.18)}section.lang-javascript{background:rgba(229,202,71,0.16)}section.lang-typescript{background:rgba(46,116,194,0.18)}section.lang-java{background:rgba(196,69,60,0.18)}section.lang-kotlin{background:rgba(193,71,167,0.18)}section.lang-go{background:rgba(0,173,181,0.18)}section.lang-cpp{background:rgba(120,80,180,0.20)}section.lang-csharp{background:rgba(83,150,80,0.18)}section.lang-php{background:rgba(98,113,178,0.20)}section.lang-bash{background:rgba(96,128,96,0.18)}section.lang-perl{background:rgba(180,120,60,0.18)}section.lang-lua{background:rgba(0,86,180,0.20)}section.lang-tcl{background:rgba(160,90,140,0.20)}section.lang-irules{background:rgba(200,70,120,0.20)}section.lang-ruby{background:rgba(204,52,45,0.18)}section.lang-elixir{background:rgba(110,73,153,0.20)}section.lang-other{background:rgba(200,200,200,0.10)}}.summary{font-size:0.9rem;color:#444;margin-bottom:0.5rem}.summary strong{color:#222}.summary p{margin:0.2rem 0}.note{font-size:0.85rem;color:#555;margin:0.4rem 0}ul{margin:0.4rem 0 0.4rem 1.2rem;padding:0}li{margin:0.15rem 0;font-size:0.9rem}table.hotspot{border-collapse:collapse;width:100%;font-size:0.85rem;background:#fff;box-shadow:0 1px 2px rgba(0,0,0,0.06);margin-bottom:0.5rem}table.hotspot th,table.hotspot td{padding:0.4rem 0.6rem;border-bottom:1px solid #e5e5e5;text-align:left;white-space:nowrap}table.hotspot th{background:#f0f0f0;cursor:pointer;user-select:none;font-weight:600}table.hotspot th:hover{background:#e5e5e5}table.hotspot th[aria-sort=ascending]::after{content:" \2191"}table.hotspot th[aria-sort=descending]::after{content:" \2193"}table.hotspot tr:nth-child(even) td{background:#fafafa}table.hotspot td.numeric{text-align:right;font-variant-numeric:tabular-nums}</style>
 </head>
 <body>
 <h1>Code Quality Metrics Summary</h1>

big-code-analysis-cli/src/html_report.rs

@@ -50,6 +50,7 @@ pub(crate) fn lang_to_name(lang: LANG) -> &'static str {
         LANG::Elixir => "elixir",
         LANG::Go => "go",
         LANG::Groovy => "groovy",
+        LANG::Irules => "irules",
         LANG::Java => "java",
         // `Javascript` has no extensions and is filtered out of
         // `public_languages`, so this arm is never reached through