Changeset fe6047c for doc/theses/mike_brooks_MMath/background.tex

Timestamp:

Dec 12, 2025, 12:18:17 PM (4 months ago)

Author:

Michael Brooks <mlbrooks@…>

Branches:

master, stuck-waitfor-destruct

Children:

67748f9, 79ba50c

Parents:

f2b74e3

Message:

Edits in early sections.

Includes explicating the connection between unsafety stats and the three collection types.

File:

• doc/theses/mike_brooks_MMath/background.tex (modified) (2 diffs)

doc/theses/mike_brooks_MMath/background.tex

@@ -620 +620 @@
 In fact, the outermost type constructor (syntactically first dimension) is really the one that determines the parameter flavour.
 
-\PAB{TODO: add examples of mycode/arrr/bugs/c-dependent/x.cfa:v5102,5103,
-which are shocking how much C ignores.}
+C ignores length information given in parameter declarations entirely, when determining a function's type.
+For example, it accepts this pair of declarations
+\begin{cfa}
+    void f( int, float[][42] );  $\C{// array of len-42 arrays}$
+    void f( int n, float[][n]  );   $\C{// array of VLAs}$
+\end{cfa}
+as a repeat, without an error about conflicting types for @f@.
+Yet, entirely different stride calculations would occur in a function body whose parameters were declared in each of the two styles.
 
 \begin{figure}
@@ -668 +674 @@
 An array parameter declaration can specify the outermost dimension with a dimension value, @[10]@ (which is ignored), an empty dimension list, @[ ]@, or a pointer, @*@, as seen in \VRef[Figure]{f:ArParmEquivDecl}.
 The rationale for rejecting the first invalid row follows shortly, while the second invalid row is nonsense, included to complete the pattern; its syntax hints at what the final row actually achieves.
-Note, in the leftmost style, the typechecker ignores the actual value even in a dynamic expression.
+Note, in the leftmost style, the typechecker ignores the actual value, even for a dynamic expression.
 \begin{cfa}
 int N;