+
+----------
+Where do type definition go?
+I don't think they go with statements, they belong separately.
+I don't want the full separation of a "type" section like Pascal
+So they probably go at the top level, equivalent to "program" - and before.
+They start with "struct" or "enum" or "record" etc.
+
+So: what about constants? These are currently statements and so affect a scope in time.
+But for declaring arrays in structs, or initial values of fields, we might want constants.
+A constant could be within a struct, but only that it too limiting. I need module-wide
+constants.
+So I guess:
+
+ const:
+ name ::= value
+ name ::= value
+
+or
+ const { name ::= value ; name ::= value }
+
+--------------
+I'm in the middle of stage-1 on structures.
+
+I need a type to parse the declaration into. It needs to be a linked list
+of fields, each of which is a type, a name, and an initial value. i.e. a 'struct field'.
+
+-----------------
+
+Numbers...
+I want signed/unsigned/bitset integers (and probably floats).
+These are different sizes, and I want to move 'type' out of 'value'
+so I can have arrays of numbers that are *just* the densely packets numbers.
+
+So there are two questions here: how will I handle values in oceani, and
+what are the semantics of numbers in ocean.
+
+I think I want bitops to requires bitsets and arith ops to require signed/unsigned.
+But there is some overlap.
+e.g. we use bitops to test if a number is a power of two
+We sometimes use bitops to multiply, but that is probably best avoided.
+use * to multiply.
+
+Converting between the two can be done with simple assignment.
+
+So + - * / % require/assume signed or unsigned
+ | & ~ << >> require/assume bitset
+
+ # accepts either and produces a bitset
+
+Other issue is overflow/underflow checking.
+Do we need another unsigned type - cyclic
+
+ i32 - signed integer in 32 bits
+ u32 - unsigned integer
+ c32 - unsigned with overflow permitted and ignored
+ b32 - bitset
+
+ int uint cint bset - whatever size.
+
+i32 and u32 detect overflow/underflow and set to NaN - all 1's
+If I want to allow overloading (such a NaN), I need a type that
+declare no overloading. s32 and c32? Or annotations. !s32 !u32
+
+So what about values in oceani? I want to separate out the type and not
+use a union.
+Where are they used?
+ - return of init, prepare, parse, dup
+ - passed to print, cmp, dup, free, to_int, to_float, to_mpq
+ - field in 'struct variable'
+ - field in 'struct lrval'
+ - result of 'interp'
+ - intermediate left/right in interp
+ - field in array and struct field
+ - field in 'struct val' for manifest constants
+
+So:
+ variable gets a 'type' pointer and a union which can be a pointer
+ to the value, or the value itself (depending on size)
+ lrval get a type pointer as well, plus the union
+ interp returns ...
+
+
+-----------------
+Struct/array initialisers.
+I like [a,b,c] rather than {a,b,c} because the latter can look like code.
+But [] is also array indexing.
+So an array initializer could look:
+ [ [1] = "hello", [5] = "there" ]
+and that is confusingly similar to nested initialization
+ [ [1,2] , [3,4] ]
+Options:
+ 1/ use different outer. {} () <> << >>
+ < is possibly as it is not a prefix operator.
+ But nesting results in <<1,2>,<3,4>> which looks like << instead of < <
+ {} I already don't like
+ () is bad enough with function calls - it is best if it is grouping only.
+ though with function calls it is a list ...
+ << [1]="hello", [2]="there" >>... I don't really like that
+
+ array[ ]
+ struct[ ]
+ No, too noisy.
+
+ 2/ use different inner syntax.
+ [ .[1] = "hello", .[5] = "hello" ]
+
+ What about a newline-based syntax:
+ a: [4]int :
+ [0] = 2
+ [1] = 3
+ [3] = 1
+
+ Nice, but doesn't actually help. Still need .[] because I want to allow
+ a one-line syntax too.
+ Maybe I just use {} after all.
+
+ a:[4]int = { [0]=2, [1]=3, [3]=1 }
+ Yes, I guess that is best.