REBOL [ file: %file-size-comparison-ctx.r date: 24-May-2006 title: "file-size-comparison-ctx" purpose: "Compare file sizes using a friendly dialect" author: "Gregg Irwin" library: [ level: 'intermediate platform: 'all type: [module function dialect] domain: [files] tested-under: [view 1.3.2 on WinXP by Gregg] support: none license: 'public-domain ; no warranty expressed or implied see-also: [%file-date-comparison-ctx.r %collect.r] ] comment: {Uses COLLECT function} ] file-size-comparison-ctx: context [ =negate-op?: none =or-equal?: none =op: none =size: 0 =size-mul: 1 =parse-end-mark: none make-lit-word: func [val] [to lit-word! :val] lit-lesser: make-lit-word "<" lit-greater: make-lit-word ">" lit-lesser-or-equal: make-lit-word "<=" lit-greater-or-equal: make-lit-word ">=" size=: [ (=size-mul: 1) [ set =size number! | set =size file! (=size: size? =size) ] opt [ 'bytes ; no change to size-mul | ['kilobytes | 'KB] (=size-mul: 1024.0) | ['megabytes | 'MB] (=size-mul: 1048576.0) | ['gigabytes | 'GB] (=size-mul: 1073741824.0) ] (=size: =size * =size-mul) ] word-comparison=: [ [ ['more | 'bigger | 'larger | 'greater] (=op: 'greater) | ['less | 'smaller] (=op: 'lesser) ] 'than opt ['or 'equal 'to (=or-equal?: true)] ] lit-comparison=: [ lit-lesser (=or-equal?: false =op: 'lesser) | lit-greater (=or-equal?: false =op: 'greater) | lit-lesser-or-equal (=or-equal?: true =op: 'lesser) | lit-greater-or-equal (=or-equal?: true =op: 'greater) ] rules=: [ (=negate-op?: =or-equal?: =op: =parse-end-mark: none) opt 'if opt ['size | size?] opt [['no | 'not] (=negate-op?: true)] [word-comparison= | lit-comparison=] (if =negate-op? [=op: pick [greater lesser] =op = 'lesser]) (=op: to word! rejoin [=op either =or-equal? ['-or-equal] [""] '?]) size= =parse-end-mark: ] set 'size-comparison-cmd? func [input [block!]] [ parse input rules= return =parse-end-mark ] set 'make-file-size-comparison-func func [spec] [ parse spec rules= either =parse-end-mark [ func [file] reduce [=op 'size? 'file =size] ] [none] ] set 'files-matching-size-spec func [ files [block!] spec [block!] ][ if match?: make-file-size-comparison-func spec [ collect 'keep [ foreach file files [if match? file [keep: file]] ] ] ] ] ; Examples ;foreach file files-matching-size-spec read %. [size >= 1024] [print [file size? file]] ;foreach file files-matching-size-spec read %. [less than or equal to 1024] [print [file size? file]] ;foreach file files-matching-size-spec read %. [>= 64 kb] [print [file size? file]] ;foreach file files-matching-size-spec read %. [smaller than 2 mb] [print [file size? file]] ;foreach file files-matching-size-spec read %. [bigger than .5 mb] [print [file size? file]] ;foreach file files-matching-size-spec read %. [larger than %view.exe] [print [file size? file]]