adsep: some lunch progress

adsep/chapter01/notes.md

@@ -25,4 +25,43 @@
   by the programmer
 + *cardinality*: the number of distinct values belonging to some type
   *T*
++ *methods of structuring*:
+  + the array
+  + the record (aka structure)
+  + the set
+  + the sequence (aka file)
++ operators provide a mechanism for using data
+  + comparison and assignment: most important basic operators
+    + assignment: `:=`
+	+ equality: `=`
+  + *transfer operator*: translate between data types
+  + *selector* instead of *getter*
 
+## Primitive data types
+
++ enum: integer used when the data type type represents a choice from
+  a small set of choices
+  + rule 1.1: **type** *T* = (*c*_1, *c*_2, …, *c*_n)
+  + cardinality of T: card(T) ← *n*
+  + ordered types define *succ(x)* and *pred(x)*
+  + ordering among values of *T* is defined by rule 1.2: (*c*_i < *c*_j) = (*i* < *j*)
+
+## Standard primitive types
+
++ four types: integer, Boolean, char, real
++ integers
+  + subset of whole numbers depending on implementation (e.g. 32-bit v. 64-bit)
+  + four basic operations: +, -, *, **div**
+  + integer division returns an integer result, e.g. for positive *m* and *n*
+  + rule 1.3: *m* - *n* < (*m* **div** *n*) * *n* <= *m*
+  + modulus operator is defined by
+  + rule 1.4: (*m* **div** *n*) * *n* + (*m* **mod** *n*) = *m*
++ real
+  + limitations on precision due to implementation
+  + real division: **/**
++ Boolean
+  + operators: **and**, **or**, **not**
+  + comparisons are operators yielding a Boolean
++ char
+  + printable character
+  + standard char ←→ integer transfer functions: *ord* and *chr*