On Wednesday 13 November 2013 12:37:15 Michael Schnell wrote: > On 11/12/2013 10:19 AM, Martin Schreiber wrote: > > If it's really bit packed you might get numerical values that require > > rather complex handling by the compiler: > > > > record tr > > x1: int64: 2; > > Invalid because int64 is defined as -800000000000..7fffffffffffffff which > > does not fit in 2 bits. > > That is not the idea. But: > > r.x1= 0 => bits = 0, 0 > r.x1= 1 => bits = 0, 1 > r.x1= -1 => bits = 1,1 > r.x1= -2 => bits = 1, 0 > > other values are truncated accordingly (see below) > > > > On the contrary the base type needs to provide at least as many bits as > given after the ":" (otherwise you could never define fields with less > than 8 bits). > > Do you intend to provide a syntax to define bit fields with more bits > than any integer base type. This in fact would be intersting but would > need you to provide an arbitrary precision integer arithmetic in the > RTL. Doable but an "interesting" Task :-) . > MSElang definitions of ordinal types is " 'type' TYPENAME '=' (BOOLEANRANGEDEF | CARDINALRANGEDEF | INTEGERRANGEDEF | CHARRANGEDEF | FLOATRANGEDEF) [: BITSIZE] ';' BOOLEANRANGEDEF = MAXCARD //MAXCARD must be 2^n-1, max 32 bit CARDINALRANGEDEF = MINCARD 'to' MAXCARD //max 64 bit INTEGERRANGEDEF = '-'MINCARD 'to' MAXCARD //max 64 bit CHARRANGEDEF = '#'MINCARD 'to' MAXCARD //max 32 bit FLOATRANGEDEF = MINFLOAT 'to' MAXFLOAT //32 or 64 bit " Without BITSIZE the size will be extended to the next byte boundary, BITSIZE must be >= the needed bits to hold the value range.
Examples: " type b8ty = $ff; //a 8 bit boolean b16ty = $ffff; //a 16 bit boolean i16ty = -$8000 to $7fff; //a 16 bit integer s8ty = 14 to 15; //a 8 bit subrange cardinal s4ty = 14 to 15: 4; //a 4 bit subrange cardinal s1ty = 14 to 15: 1; //a 1 bit subrange cardinal 0 -> 14, 1 -> 15 c16ty = #$0000 to #$ffff; //a 16 bit character f32ty = -3.4e38 to 3.4e38; //a single precision float f64ty = -1.7e308 to 1.7e308 //a double precision float sf64ty = 0.0 to 10.0: 64; //a double precision subrange float " 'integer','cardinal','int8',int16... are *not* part of MSElang! int64 is defined in systypes.mla: " int64 = -$8000000000000000 to $7fffffffffffffff: 64; " therefore "int64: 2;" is invalid, it must be written as "-2 to 1" or "-2 to 1: 2". Also possible is "100 to 103: 2". :-) Please see the Wiki: https://gitorious.org/mseide-msegui/pages/Mselang Martin ------------------------------------------------------------------------------ DreamFactory - Open Source REST & JSON Services for HTML5 & Native Apps OAuth, Users, Roles, SQL, NoSQL, BLOB Storage and External API Access Free app hosting. Or install the open source package on any LAMP server. Sign up and see examples for AngularJS, jQuery, Sencha Touch and Native! http://pubads.g.doubleclick.net/gampad/clk?id=63469471&iu=/4140/ostg.clktrk _______________________________________________ mseide-msegui-talk mailing list mseide-msegui-talk@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mseide-msegui-talk
