Changes between Version 44 and Version 45 of IR2

Timestamp:

04/28/21 18:26:34 (5 years ago)

Author:

siegel

Comment:

--

IR2

@@ -133 +133 @@
 
 === Notes ===
+
 * Sequences, sets, maps, and relations are immutable.   An assignment using objects of this type creates a new copy of the object, just as with primitive types like `int`.
 * The main difference between the array type and the sequence type is that elements of an array are addressable, i.e., one can form a pointer such as `&a[i]`.  This is not possible with sequences, sets, maps, or relations---there is no way to have a pointer to any component of such a type.
 * The difference between the function type and map type: a function is really a procedure in the language, so it can modify the state as well as return a value.    This is like the C notion of "function".   A map is a logical partial function: it is defined on some subset of the domain type, it will always "return" the same value on a given input, and reading it cannot modify the state.
-
 
 
@@ -161 +161 @@
 
 {{{
+lvalue:
+  | ID
+  | lvalue '[' expr ']'
+  | lvalue '.' ID
+  | '*' expr
+  ;
 expr:
-    $new(type-name)  /* returns a new arbitrary value of the given type */
-  |
+  | lvalue
+  | STRING
+  | INT
+  | REAL
+  | FLOAT
+  | expr '+' expr  /* numeric or pointer addition */
+  | expr '-' expr  /* numeric or pointer subtraction */
+  | expr '/' expr  /* division */
+  | expr '%' expr  /* modulo */
+  | expr '&&' expr  /* logical and */
+  | expr '||' expr  /* logical or */
+  | expr '==' expr  /* equality */
+  | expr '!=' expr  /* inequality */
+  | expr '[' expr ']'  /* array or map read */
+  | '!' expr  /* logical not */
+  | '(' expr ')'
+  | '*' expr  /* pointer dereference */
+  | '&' lvalue  /* address-of */
+  | $new(type-name)  /* returns a new arbitrary value of the given type */
 
 }}}