ref: 1018d7a7091fd5e0433f501a3474cdc3fec322cc
dir: /appl/cmd/fmt.b/
implement Fmt; # # Copyright © 2002 Lucent Technologies Inc. # based on the Plan 9 command; subject to the Lucent Public License 1.02 # this Vita Nuova variant uses Limbo channels and processes to avoid accumulating words # # # block up paragraphs, possibly with indentation # include "sys.m"; sys: Sys; include "draw.m"; include "bufio.m"; bufio: Bufio; Iobuf: import bufio; include "arg.m"; Fmt: module { init: fn(nil: ref Draw->Context, nil: list of string); }; extraindent := 0; # how many spaces to indent all lines indent := 0; # current value of indent, before extra indent length := 70; # how many columns per output line join := 1; # can lines be joined? maxtab := 8; bout: ref Iobuf; Word: adt { text: string; indent: int; bol: int; }; init(nil: ref Draw->Context, args: list of string) { sys = load Sys Sys->PATH; bufio = load Bufio Bufio->PATH; arg := load Arg Arg->PATH; arg->init(args); arg->setusage("fmt [-j] [-i indent] [-l length] [file...]"); while((c := arg->opt()) != 0) case(c){ 'i' => extraindent = int arg->earg(); 'j' => join = 0; 'w' or 'l' => length = int arg->earg(); * => arg->usage(); } args = arg->argv(); if(length <= extraindent){ sys->fprint(sys->fildes(2), "fmt: line length<=indentation\n"); raise "fail:length"; } arg = nil; err := ""; bout = bufio->fopen(sys->fildes(1), Bufio->OWRITE); if(args == nil){ bin := bufio->fopen(sys->fildes(0), Bufio->OREAD); fmt(bin); }else for(; args != nil; args = tl args){ bin := bufio->open(hd args, Bufio->OREAD); if(bin == nil){ sys->fprint(sys->fildes(2), "fmt: can't open %s: %r\n", hd args); err = "open"; }else{ fmt(bin); if(tl args != nil) bout.putc('\n'); } } bout.flush(); if(err != nil) raise "fail:"+err; } fmt(f: ref Iobuf) { words := chan of ref Word; spawn parser(f, words); printwords(words); } parser(f: ref Iobuf, words: chan of ref Word) { while((s := f.gets('\n')) != nil){ if(s[len s-1] == '\n') s = s[0:len s-1]; parseline(s, words); } words <-= nil; } parseline(line: string, words: chan of ref Word) { ind: int; (line, ind) = indentof(line); indent = ind; bol := 1; for(i:=0; i < len line;){ # find next word if(line[i] == ' ' || line[i] == '\t'){ i++; continue; } # where does this word end? for(l:=i; l < len line; l++) if(line[l]==' ' || line[l]=='\t') break; words <-= ref Word(line[i:l], indent, bol); bol = 0; i = l; } if(bol) words <-= ref Word("", -1, bol); } indentof(line: string): (string, int) { ind := 0; for(i:=0; i < len line; i++) case line[i] { ' ' => ind++; '\t' => ind += maxtab; ind -= ind%maxtab; * => return (line, ind); } # plain white space doesn't change the indent return (line, indent); } printwords(words: chan of ref Word) { # one output line per loop nw := <-words; while((w := nw) != nil){ # if it's a blank line, print it if(w.indent == -1){ bout.putc('\n'); nw = <-words; continue; } # emit leading indent col := extraindent+w.indent; printindent(col); # emit words until overflow; always emit at least one word for(n:=0;; n++){ bout.puts(w.text); col += len w.text; if((nw = <-words) == nil) break; # out of words if(nw.indent != w.indent) break; # indent change nsp := nspaceafter(w.text); if(col+nsp+len nw.text > extraindent+length) break; # fold line if(!join && nw.bol) break; for(j:=0; j<nsp; j++) bout.putc(' '); # emit space; another word will follow col += nsp; w = nw; } bout.putc('\n'); } } printindent(w: int) { while(w >= maxtab){ bout.putc('\t'); w -= maxtab; } while(--w >= 0) bout.putc(' '); } # give extra space if word ends with punctuation nspaceafter(s: string): int { if(len s < 2) return 1; if(len s < 4 && s[0] >= 'A' && s[0] <= 'Z') return 1; # assume it's a title, not full stop if((c := s[len s-1]) == '.' || c == '!' || c == '?') return 2; return 1; }