/ numberseparators /

Number Separator Characters

description:: ANS Forth specifies that '.' (dot) must be used in both double numbers and floating-point numbers, whatever notation is accepted in the country where the program is used. In addition, there is no way to separate groups of characters, for example, can you determine from the first sight whether fffffff is a 32-bit value with all bits set? DP-CHAR ( -- a-addr ) A variable, stores ASCII value of double number separator. Default: '.' FP-CHAR ( -- a-addr ) A variable, stores ASCII value of float number separator. Default: '.' NU-CHAR ( -- a-addr ) A variable, stores ASCII value of the separator that is ignored. 'NU' stands for 'not used'. Default: '_'
Examples:: hex fff_ffff is clearly different from ffff_ffff after the assignment CHAR , FP-CHAR ! 123,4 denotes a floating-point number while 123.4 is a double number.
original messages:: From: sfp@mpeltd.demon.co.uk (Stephen Pelc) Message-ID: <3bd6b8e2.394732224@192.168.0.1> [...] There is a ... strategy which MPE has used for several years, and which satisfies most international users. Define two system variables DP-CHAR and FP-CHAR to hold the double number and floating point number separators. Use these variables instead of constants in your text scanning routines. For ANS use set both of these to '.' For some countries use: char , dp-char ! char . fp-char ! For others use: char . dp-char ! char , fp-char ! and so on. I am also considering adding a character which can be ignored during scanning for numbers. This is useful for masks and literal addresses, especially for embedded systems, e.g. $BF00:0040 for a 32 bit address. I suggest the use of ':' as the default, and the system variable will be called NU-CHAR for not-used. Stephen From: Keith Wootten <Keith@wootten.demon.co.uk> Message-ID: <gT+1NEAIEu17EwYs@wootten.demon.co.uk> >I am also considering adding a character which can be ignored >during scanning for numbers. [...] Can I suggest _ as a default instead? I use this a lot for binary particularly when bits are grouped for different purposes in a configuration register. I tried a few, but _ is IMO the clearest. eg %1011:0000:101010:001000:111010001000 or %1011_0000_101010_001000_111010001000
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