WIP: Expansion context analyzer implementation

Co-authored-by: jackfirth <[email protected]>

Author: Copilot

default-recommendations/analyzers/expansion-context-analyzer-test.rkt

@@ -0,0 +1,29 @@
+#lang resyntax/test
+
+
+require: resyntax/default-recommendations/analyzers/expansion-context-analyzer expansion-context-analyzer
+header: - #lang racket/base
+
+
+analysis-test: "code in a module is in a module context"
+- (+ 1 2 3)
+@inspect - (+ 1 2 3)
+@property expansion-context
+@assert module
+
+
+analysis-test: "function arguments are in an expression context"
+- (+ 1 2 3)
+@inspect - 2
+@property expansion-context
+@assert expression
+
+
+analysis-test: "code in a function body is in an internal definition context"
+--------------------
+(define (f)
+  (+ 1 2 3))
+--------------------
+@inspect - (+ 1 2 3)
+@property expansion-context
+@assert internal-definition

default-recommendations/analyzers/expansion-context-analyzer.rkt

@@ -0,0 +1,86 @@
+#lang racket/base
+
+
+(require racket/contract/base)
+
+
+(provide
+ (contract-out
+  [expansion-context-analyzer expansion-analyzer?]))
+
+
+(require racket/stream
+         rebellion/streaming/transducer
+         resyntax/private/analyzer
+         resyntax/private/syntax-path
+         resyntax/private/syntax-property-bundle
+         resyntax/private/syntax-traversal
+         syntax/parse)
+
+
+;@----------------------------------------------------------------------------------------------------
+
+
+(define (annotate-expansion-contexts expanded-stx)
+  (let loop ([expanded-stx expanded-stx] [phase 0])
+    (syntax-search expanded-stx
+      #:literal-sets ([kernel-literals #:phase phase])
+      
+      ;; Phase mismatch - recurse with correct phase
+      [(id:id _ ...)
+       #:do [(define id-phase (syntax-property (attribute id) 'phase))]
+       #:when (not (equal? id-phase phase))
+       (loop this-syntax id-phase)]
+
+      ;; Skip quote-syntax - no expansion context inside
+      [(quote-syntax _) (stream)]
+      
+      ;; Forms directly under #%module-begin are in module context
+      [(#%module-begin form ...)
+       (for/stream ([form-stx (in-list (attribute form))])
+         (define path (syntax-property form-stx 'expansion-path))
+         (and path (syntax-property-entry path 'expansion-context 'module)))]
+      
+      ;; Body forms of lambda are in internal-definition context
+      [(lambda formals body ...+)
+       (for/stream ([body-stx (in-list (attribute body))])
+         (define path (syntax-property body-stx 'expansion-path))
+         (and path (syntax-property-entry path 'expansion-context 'internal-definition)))]
+      
+      ;; Body forms of case-lambda are in internal-definition context
+      [(case-lambda [formals body ...+] ...)
+       (for*/stream ([bodies (in-list (attribute body))]
+                     [body-stx (in-list bodies)])
+         (define path (syntax-property body-stx 'expansion-path))
+         (and path (syntax-property-entry path 'expansion-context 'internal-definition)))]
+      
+      ;; Body forms of let-values and letrec-values are in internal-definition context
+      [(~or (let-values ([vars rhs] ...) body ...+)
+            (letrec-values ([vars rhs] ...) body ...+))
+       (stream-append
+        ;; RHS expressions are in expression context
+        (for/stream ([rhs-stx (in-list (attribute rhs))])
+          (define path (syntax-property rhs-stx 'expansion-path))
+          (and path (syntax-property-entry path 'expansion-context 'expression)))
+        ;; Body forms are in internal-definition context
+        (for/stream ([body-stx (in-list (attribute body))])
+          (define path (syntax-property body-stx 'expansion-path))
+          (and path (syntax-property-entry path 'expansion-context 'internal-definition))))]
+      
+      ;; Subforms of #%plain-app (function applications) are in expression context
+      [(app-id:id subform ...)
+       #:when (free-identifier=? (attribute app-id) #'#%plain-app)
+       (stream-filter
+        values
+        (for/stream ([subform-stx (in-list (attribute subform))])
+          (define path (syntax-property subform-stx 'expansion-path))
+          (and path (syntax-property-entry path 'expansion-context 'expression))))])))
+
+
+(define expansion-context-analyzer
+  (make-expansion-analyzer
+   #:name 'expansion-context-analyzer
+   (λ (expanded-stx)
+     (define labeled-stx (syntax-label-paths expanded-stx 'expansion-path))
+     (transduce (annotate-expansion-contexts labeled-stx)
+                #:into into-syntax-property-bundle))))