Changeset 09bdf2d

Timestamp:

Jul 29, 2024, 4:55:50 PM (2 hours ago)

Author:

JiadaL <j82liang@…>

Branches:

master

Children:

dd78dbc

Parents:

f3d2a4f

Message:

Add CEnum.tex

File:

• doc/theses/jiada_liang_MMath/CFAenum.tex (modified) (4 diffs)

doc/theses/jiada_liang_MMath/CFAenum.tex

@@ -30 +30 @@
 Opaque enum is a special CFA enumeration type, where the internal representation is chosen by the compiler and hidden from users.
 Compared C enum, opaque enums are more restrictive in terms of typing, and cannot be implicitly converted to integers.
-Enumerators of opaque enum cannot have initializer. Declaring initializer in the body of opaque enum results in a compile error.
+Enumerators of opaque enum cannot have initializer. Declaring initializer in the body of opaque enum results in a compile time error.
 \begin{cfa}
 enum@()@ Planets { MERCURY, VENUS, EARTH, MARS, JUPITER, SATURN, URANUS, NEPTUNE };
@@ -114 +114 @@
 \subsection{Value Conversion}
 C has an implicit type conversion from an enumerator to its base type @int@.
-Correspondingly, \CFA has an implicit conversion from a typed enumerator to its base type.
+Correspondingly, \CFA has an implicit conversion from a typed enumerator to its base type. The feature that allows Typed enumeration 
+seemlyless used 
 \begin{cfa}
 char currency = Dollar;
@@ -120 +121 @@
 foo( Fred );
 \end{cfa}
-% \CFA enumeration being resolved as its base type because \CFA inserts an implicit @value()@ call on an \CFA enumeration.
+
 During the resolution of expression e with \CFA enumeration type, \CFA adds @value(e)@ as an additional candidate with an extra \newterm{value} cost.
 For expression @char currency = Dollar@, the is no defined conversion from Dollar (\CFA enumeration) type to basic type and the conversion cost is @infinite@, 
@@ -154 +155 @@
 try to resolve it as a @CfaEnum@, rather to insert a @value@ conversion.
 
-\subsection{Coercion}
-While implicit conversion from a \CFA enumeration has been disabled, a explicit coercion cast to basic type is still possible to be consistent with C. In which case, 
-\CFA converts a \CFA enumeration variable as a basic type, with the value of the @position@ of the variable.
+\subsection{Explicit Conversion}
+Explicit conversion is allowed on \CFA enumeration to an integral type, in which case \CFA converts \CFA enumeration into its underlying representation,
+which is its @position@.
 
 \section{Auto Initialization}