--- /dev/null
+/ Plan 9's /lib/units
+/ http://plan9.bell-labs.com/sources/plan9/lib/units
+/
+/ Copyright (C) 2003, Lucent Technologies Inc. and others. All Rights Reserved.
+/ Distributed under the terms of the Lucent Public License Version 1.02
+/ See http://plan9.bell-labs.com/plan9/license.html
+/
+/order of evaluation
+/ + -
+/ * /
+/ juxtaposition (meaning *)
+/ ¹ ² ³ ^
+/ | (meaning /)
+/ name number ()
+
+/dimensions
+m #
+kg #
+sec #
+coul #
+candela #
+$ #
+radian #
+bit #
+erlang #
+°K #
+°C #
+°F #
+
+/constants
+
+π 3.14159265358979323846
+pi π
+c 2.997925e+8 m/sec
+g 9.80665 m/sec²
+au 1.49597871e+11 m
+mole 6.022169e+23
+e 1.6021917e-19 coul
+energy c²
+force g
+mercury 1.33322e+5 kg/m²sec²
+hg mercury
+h 6.62620e-34 m²kg/sec
+ℏ h/2 π
+hbar ℏ
+nonillion 1e30
+octillion 1e27
+septillion 1e24
+sextillion 1e21
+pentillion 1e18
+quadrillion 1e15
+trillion 1e12
+billion 1e9
+million 1e6
+thousand 1e3
+hundred 1e2
+
+/dimensionless
+
+° 1|180 π radian
+degree °
+circle 2 π radian
+turn 2 π radian
+grad .9 °
+arcdeg 1 °
+arcmin 1|60 °
+arcsec 1|3600 °
+ccs 1|36 erlang
+
+steradian radian²
+sphere 4 π steradian
+sr steradian
+giga 1024 1024 1024
+
+/Time
+
+second sec
+s sec
+minute 60 sec
+min minute
+hour 60 min
+hr hour
+day 24 hr
+da day
+week 7 day
+year 365.24219879 day
+yr year
+month 1|12 year
+ms millisec
+us microsec
+
+/Mass
+
+gram millikg
+gm gram
+mg milligram
+metricton kilokg
+
+/Avoirdupois
+
+lb .45359237 kg
+lbf lb g
+pound lb
+ounce 1|16 lb
+oz ounce
+dram 1|16 oz
+dr dram
+grain 1|7000 lb
+gr grain
+shortton 2000 lb
+ton shortton
+longton 2240 lb
+
+/Apothecary
+
+scruple 20 grain
+apdram 60 grain
+apounce 480 grain
+troyounce apounce
+appound 5760 grain
+troypound appound
+
+/Length
+
+meter m
+cm centimeter
+mm millimeter
+km kilometer
+nm nanometer
+micron micrometer
+µ micrometer
+Å decinanometer
+angstrom Å
+
+inch 2.54 cm
+" inch
+in inch
+inches inch
+' 12"
+foot 12 in
+feet foot
+ft foot
+yard 3 ft
+yd yard
+rod 5.5 yd
+rd rod
+mile 5280 ft
+mi mile
+
+british 1200|3937 m/ft
+nmile 1852 m
+
+acre 4840 yd²
+
+cc cm³
+liter kilocc
+ml milliliter
+
+/US Liquid
+
+gallon 231 in³
+imperial 1.20095
+epa 0.8
+gal gallon
+quart 1|4 gal
+qt quart
+pint 1|2 qt
+pt pint
+
+floz 1|16 pt
+fldr 1|8 floz
+
+/US Dry
+
+dry 268.8025 in³/gallon
+peck 8 dry quart
+pk peck
+bushel 4 peck
+bu bushel
+
+/British
+
+brgallon 277.420 in³
+brquart 1|4 brgallon
+brpint 1|2 brquart
+brfloz 1|20 brpint
+brpeck 554.84 in³
+brbushel 4 brpeck
+
+/Energy Work
+
+newton kg m/sec²
+nt newton
+joule nt m
+cal 4.1868 joule
+
+/Electrical
+
+coulomb coul
+ampere coul/sec
+amp ampere
+watt joule/sec
+volt watt/amp
+Ω volt/amp
+ohm Ω
+mho 1/Ω
+farad coul/volt
+henry sec²/farad
+weber volt sec
+
+/Light
+
+cd candela
+lumen cd sr
+lux cd sr/m²
+
+/ MONEY DATE
+/ Fri Oct 27 15:52:13 EDT 2000
+
+/ MONEY START
+argentpeso 1 | .9998 $
+australiadollar 1 | 1.9175 $
+brazilreal 1 | 1.9300 $
+britainpound 1 | .6972 $
+canadadollar 1 | 1.5237 $
+chilepeso 1 | 576.45 $
+chinayuan 1 | 8.2782 $
+colombiapeso 1 | 2165.00 $
+czechrepkoruna 1 | 42.11 $
+denmarkkrone 1 | 9.0134 $
+dominicanpeso 1 | 16.00 $
+egyptpound 1 | 3.6750 $
+euro 1 | 1.08863 $
+hongkongdollar 1 | 7.7991 $
+hungaryforint 1 | 317.59 $
+indiarupee 1 | 46.600 $
+indnsiarupiah 1 | 9025.00 $
+israelshekel 1 | 4.1450 $
+japanyen 1 | 108.34 $
+jordandinar 1 | .71098 $
+lebanonpound 1 | 1514.00 $
+malaysiaringgit 1 | 3.7996 $
+mexicopeso 1 | 9.6850 $
+newzealanddollar 1 | 2.4938 $
+norwaykrone 1 | 9.5940 $
+pakistanrupee 1 | 57.75 $
+perunewsol 1 | 3.510 $
+philpinspeso 1 | 50.10 $
+polandzloty 1 | 4.70 $
+russiaruble 1 | 27.9200 $
+sdr 1 | .7841 $
+saudiarabriyal 1 | 3.7508 $
+singaporedollar 1 | 1.7546 $
+slovakrepkoruna 1 | 52.65 $
+southafricarand 1 | 7.6725 $
+southkoreawon 1 | 1137.20 $
+swedenkrona 1 | 10.2621 $
+switzerlndfranc 1 | 1.8195 $
+taiwandollar 1 | 32.09 $
+thailandbaht 1 | 43.58 $
+turkeylira 1 | 687860 $
+uaedirham 1 | 3.6728 $
+uruguaynewpeso 1 | 12.4180 $
+venezuelabolivar 1 | 693.2500 $
+/ MONEY END
+
+€ euro
+£ britainpound
+¥ japanyen
+dollar $
+
+bef 1 | 40.3399 €
+belgiumfranc bef
+dem 1 | 1.95583 €
+germanymark dem
+grd 1 | 340.750 €
+greecedrachma grd
+esp 1 | 166.386 €
+spainpeseta esp
+frf 1 | 6.55957 €
+francefranc frf
+iep 1 | .787564 €
+irelandpunt iep
+itl 1 | 1936.27 €
+italylira itl
+luf 1 | 40.3399 €
+luxembourgfranc luf
+nlg 1 | 2.20371 €
+netherlandsguilder nlg
+ats 1 | 13.7603 €
+austriaschilling ats
+pte 1 | 200.482 €
+portugalescudo pte
+fim 1 | 5.94573 €
+finlandmark fim
+
+baht thailandbaht
+bolivar venezuelabolivar
+brpound britainpound
+dinar jordandinar
+dirham uaedirham
+drachma greecedrachma
+escudo portugalescudo
+forint hungaryforint
+franc francefranc
+guilder netherlandsguilder
+krona swedenkrona
+lira italylira
+mark germanymark
+peseta spainpeseta
+peso mexicopeso
+punt irelandpunt
+rand southafricarand
+real brazilreal
+yuan chinayuan
+ringgit malaysiaringgit
+riyal saudiarabriyal
+ruble russiaruble
+rupee indiarupee
+rupiah indnsiarupiah
+shekel israelshekel
+sol perunewsol
+won southkoreawon
+yen japanyen
+zloty polandzloty
+
+usdollar dollar
+sterling britainpound | pound
+poundsterling britainpound
+
+/bits
+
+baud bit/sec
+byte 8 bit
+short 2 byte
+long 4 byte
+vlong 8 bytes
+frame 2352 byte
+
+/Australian liquid measure
+
+pony 7 brfloz
+midie 10 brfloz
+pot midie
+handle midie
+schooner 15 brfloz
+jug 40 brfloz
+resch midie
+alf midie
+tinny 13 brfloz
+stubby tinny
+twisty 250 ml
+longneck 2 tinny
+slab 24 tinny
+sixpack 6 tinny
+nip brfloz
+
+/wine
+winebottle 750 ml
+balthazar 16 winebottle
+jeroboam 4 winebottle
+magnum 2 winebottle
+mathusalem 8 winebottle
+methuselah 8 winebottle
+nebuchadnezzar 20 winebottle
+rehoboam 6 winebottle
+salmanazar 12 winebottle
+split 0.25 winebottle
+jigger 1.5 floz
+
+/Trivia
+
+% 1|100
+admiraltyknot 6080 ft/hr
+ε₀ (1e-9/36π) farad/m
+α (1/4π ε₀) e²/ℏ c
+alpha α
+apostilb cd/π m²
+are 1e+2 m²
+arpentcan 27.52 mi
+arpentlin 191.835 ft
+astronomicalunit au
+atmosphere 1.01325e+5 nt/m²
+atm atmosphere
+atomicmassunit 1.66044e-27 kg
+amu atomicmassunit
+bag 94 lb
+bakersdozen 13
+bar 1e+5 nt/m²
+barie 1e-1 nt/m²
+barleycorn 1|3 in
+barn 1e-28 m²
+barrel 42 gal
+barye 1e-1 nt/m²
+bev 1e+9 e volt
+biot 10 amp
+blondel cd/π m²
+boardfoot 144 in³
+bolt 40 yd
+bottommeasure 1|40 in
+britishthermalunit 1.05506e+3 joule
+btu britishthermalunit
+quad 1.0e+15 btu
+refrigeration 12000 btu/ton hour
+buck dollar
+cable 720 ft
+caliber 1e-2 in
+calorie cal
+carat 205 mg
+cent centidollar
+cental 100 lb
+centesimalminute 1e-2 grad
+centesimalsecond 1e-4 grad
+century 100 year
+cfs ft³/sec
+chain 66 ft
+circularinch 1|4 π in²
+circularmil 1e-6|4 π in²
+clusec 1e-8 mm hg m³/s
+coomb 4 bu
+cord 128 ft³
+cordfoot cord
+crith 9.06e-2 gm
+cubit 18 in
+cup 1|2 pt
+curie 3.7e+10/sec
+cusec ft³/sec
+dalton amu
+decade 10 yr
+degK °K
+degC °C
+degF °F
+dipotre 1/m
+displacementton 35 ft³
+doppelzentner 100 kg
+dozen 12
+drop .03 cm³
+dyne cm gm/sec²
+electronvolt e volt
+ell 45 in
+engineerschain 100 ft
+engineerslink 100|100 ft
+equivalentfootcandle lumen/π ft²
+equivalentlux lumen/π m²
+equivalentphot cd/π cm²
+erg cm²gm/sec²
+ev e volt
+faraday 9.652e+4 coul
+fathom 6 ft
+fermi 1e-15 m
+fifth 4|5 qt
+fin 5 dollar
+finger 7|8 in
+firkin 9 gal
+footcandle lumen/ft²
+footlambert cd/π ft²
+fortnight 14 da
+franklin 3.33564e-10 coul
+frigorie kilocal
+furlong 220 yd
+galileo 1e-2 m/sec²
+gamma 1e-9 weber/m²
+gauss 1e-4 weber/m²
+geodeticfoot british ft
+geographicalmile 1852 m
+gilbert 7.95775e-1 amp
+gill 1|4 pt
+gross 144
+gunterschain 22 yd
+hand 4 in
+hectare 1e+4 m²
+hefnercandle .92 cd
+hertz 1/sec
+hogshead 2 barrel
+hd hogshead
+homestead 1|4 mi²
+horsepower 550 ft lb g/sec
+hp horsepower
+hyl gm force sec²/m
+hz 1/sec
+imaginarycubicfoot 1.4 ft³
+karat 1|24
+kcal kilocal
+kcalorie kilocal
+kev 1e+3 e volt
+key kg
+khz 1e+3/sec
+kilderkin 18 gal
+knot nmile/hr
+kwh kilowatt hour
+lambert cd/π cm²
+langley cal/cm²
+last 80 bu
+league 3 mi
+lightyear c yr
+ly lightyear
+lightsecond c sec
+line 1|12 in
+link 66|100 ft
+longhundredweight 112 lb
+longquarter 28 lb
+lusec 1e-6 mm hg m³/s
+mach 331.46 m/sec
+marineleague 3 nmile
+maxwell 1e-8 weber
+metriccarat 200 mg
+mev 1e+6 e volt
+mgd megagal/day
+mh millihenry
+mhz 1e+6/sec
+mil 1e-3 in
+millenium 1000 year
+minersinch 1.5 ft³/min
+minim 1|60 fldr
+mo month
+mpg mile/gal
+mph mile/hr
+nail 1|16 yd
+nauticalmile nmile
+nit cd/m²
+noggin 1|8 qt
+nox 1e-3 lux
+ns nanosec
+oersted 2.5e+2 amp/m π
+oe oersted
+pace 36 in
+palm 3 in
+parasang 3.5 mi
+parsec au radian/arcsec
+pascal nt/m²
+pc parsec
+pennyweight 1|20 oz
+percent %
+perch rd
+pf picofarad
+phot lumen/cm²
+pica 1|6 in
+pieze 1e+3 nt/m²
+pipe 4 barrel
+point 1|72 in
+poise gm/cm sec
+pole rd
+poundal ft lb/sec²
+pdl poundal
+proof 1/200
+psi lb g/in²
+quarter 9 in
+quartersection 1|4 mi²
+quintal 100 kg
+quire 25
+rad 100 erg/gm
+ream 500
+registerton 100 ft³
+rhe 10 m²/nt sec
+rontgen 2.58e-4 curie/kg
+rood 1.21e+3 yd
+rope 20 ft
+rutherford 1e+6/sec
+rydberg 1.36054e+1 ev
+sabin 1 ft²
+sack 3 bu
+seam 8 bu
+section mi²
+shippington 40 ft³
+shorthundredweight 100 lb
+shortquarter 25 lb
+siemens 1/Ω
+σ 5.66956e-5 erg/cm² °K^4 sec
+sigma σ
+skein 120 yd
+skot 1e-3 apostilb
+slug lb g sec²/ft
+span 9 in
+spat 4 π sr
+spindle 14400 yd
+square 100 ft²
+squidge 1|972 inch
+catsquidge 1|432 inch
+stere m³
+sthene 1e+3 nt
+stilb cd/cm²
+stoke 1e-4 m²/sec
+stone 14 lb
+strike 2 bu
+surveyfoot british ft
+surveyorschain 66 ft
+surveyorslink 66|100 ft
+tablespoon 4 fldr
+teaspoon 4|3 fldr
+tesla weber/m²
+therm 1e+5 btu
+thermie 1e+6 cal
+timberfoot ft³
+tnt 4.6e+6 m²/sec²
+tonne 1e+6 gm
+torr mm hg
+township 36 mi²
+tun 8 barrel
+water .22491|2.54 kg/m²sec²
+wey 40 bu
+weymass 252 lb
+Xunit 1.00202e-13 m
+k 1.38047e-16 erg/°K
+foal 9223372036854775807
--- /dev/null
+// Derived from Plan 9's /sys/src/cmd/units.y
+// http://plan9.bell-labs.com/sources/plan9/sys/src/cmd/units.y
+//
+// Copyright (C) 2003, Lucent Technologies Inc. and others. All Rights Reserved.
+// Portions Copyright 2009 The Go Authors. All Rights Reserved.
+// Distributed under the terms of the Lucent Public License Version 1.02
+// See http://plan9.bell-labs.com/plan9/license.html
+
+%{
+
+// units.y
+// example of a goyacc program
+// usage is
+// goyacc units.y (produces y.go)
+// 6g y.go
+// 6l y.6
+// ./6.out $GOROOT/src/cmd/goyacc/units
+// you have: c
+// you want: furlongs/fortnight
+// * 1.8026178e+12
+// / 5.5474878e-13
+// you have:
+
+import
+(
+ "flag";
+ "io";
+ "fmt";
+ "bufio";
+ "os";
+ "math";
+ "strconv";
+ "utf8";
+)
+
+const
+(
+ Ndim = 15; // number of dimensions
+ Maxe = 695; // log of largest number
+)
+
+type Node
+struct
+{
+ vval float64;
+ dim [Ndim]int8;
+}
+
+type Var
+struct
+{
+ name string;
+ node Node;
+}
+
+var fi *bufio.Reader // input
+var fund [Ndim]*Var // names of fundamental units
+var line string // current input line
+var lineno int // current input line number
+var linep int // index to next rune in unput
+var nerrors int // error count
+var one Node // constant one
+var peekrune int // backup runt from input
+var retnode1 Node
+var retnode2 Node
+var retnode Node
+var sym string
+var vflag bool
+
+%}
+
+%union
+{
+ node Node;
+ vvar *Var;
+ numb int;
+ vval float64;
+}
+
+%type <node> prog expr expr0 expr1 expr2 expr3 expr4
+
+%token <vval> VAL
+%token <vvar> VAR
+%token <numb> SUP
+%%
+prog:
+ ':' VAR expr
+ {
+ var f int;
+
+ f = int($2.node.dim[0]);
+ $2.node = $3;
+ $2.node.dim[0] = 1;
+ if f != 0 {
+ Error("redefinition of %v", $2.name);
+ } else
+ if vflag {
+ fmt.Printf("%v\t%v\n", $2.name, &$2.node);
+ }
+ }
+| ':' VAR '#'
+ {
+ var f, i int;
+
+ for i=1; i<Ndim; i++ {
+ if fund[i] == nil {
+ break;
+ }
+ }
+ if i >= Ndim {
+ Error("too many dimensions");
+ i = Ndim-1;
+ }
+ fund[i] = $2;
+
+ f = int($2.node.dim[0]);
+ $2.node = one;
+ $2.node.dim[0] = 1;
+ $2.node.dim[i] = 1;
+ if f != 0 {
+ Error("redefinition of %v", $2.name);
+ } else
+ if vflag {
+ fmt.Printf("%v\t#\n", $2.name);
+ }
+ }
+| ':'
+ {
+ }
+| '?' expr
+ {
+ retnode1 = $2;
+ }
+| '?'
+ {
+ retnode1 = one;
+ }
+
+expr:
+ expr4
+| expr '+' expr4
+ {
+ add(&$$, &$1, &$3);
+ }
+| expr '-' expr4
+ {
+ sub(&$$, &$1, &$3);
+ }
+
+expr4:
+ expr3
+| expr4 '*' expr3
+ {
+ mul(&$$, &$1, &$3);
+ }
+| expr4 '/' expr3
+ {
+ div(&$$, &$1, &$3);
+ }
+
+expr3:
+ expr2
+| expr3 expr2
+ {
+ mul(&$$, &$1, &$2);
+ }
+
+expr2:
+ expr1
+| expr2 SUP
+ {
+ xpn(&$$, &$1, $2);
+ }
+| expr2 '^' expr1
+ {
+ var i int;
+
+ for i=1; i<Ndim; i++ {
+ if $3.dim[i] != 0 {
+ Error("exponent has units");
+ $$ = $1;
+ break;
+ }
+ }
+ if i >= Ndim {
+ i = int($3.vval);
+ if float64(i) != $3.vval {
+ Error("exponent not integral");
+ }
+ xpn(&$$, &$1, i);
+ }
+ }
+
+expr1:
+ expr0
+| expr1 '|' expr0
+ {
+ div(&$$, &$1, &$3);
+ }
+
+expr0:
+ VAR
+ {
+ if $1.node.dim[0] == 0 {
+ Error("undefined %v", $1.name);
+ $$ = one;
+ } else
+ $$ = $1.node;
+ }
+| VAL
+ {
+ $$ = one;
+ $$.vval = $1;
+ }
+| '(' expr ')'
+ {
+ $$ = $2;
+ }
+%%
+
+func
+Lex() int
+{
+ var c, i int;
+
+ c = peekrune;
+ peekrune = ' ';
+
+loop:
+ if (c >= '0' && c <= '9') || c == '.' {
+ goto numb;
+ }
+ if ralpha(c) {
+ goto alpha;
+ }
+ switch c {
+ case ' ', '\t':
+ c = getrune();
+ goto loop;
+ case '×':
+ return '*';
+ case '÷':
+ return '/';
+ case '¹', 'ⁱ':
+ yylval.numb = 1;
+ return SUP;
+ case '²', '':
+ yylval.numb = 2;
+ return SUP;
+ case '³', '':
+ yylval.numb = 3;
+ return SUP;
+ }
+ return c;
+
+alpha:
+ sym = "";
+ for i=0;; i++ {
+ sym += string(c);
+ c = getrune();
+ if !ralpha(c) {
+ break;
+ }
+ }
+ peekrune = c;
+ yylval.vvar = lookup(0);
+ return VAR;
+
+numb:
+ sym = "";
+ for i=0;; i++ {
+ sym += string(c);
+ c = getrune();
+ if !rdigit(c) {
+ break;
+ }
+ }
+ peekrune = c;
+ f, err := strconv.Atof64(sym);
+ if err != nil {
+ fmt.Printf("error converting %v", sym);
+ f = 0;
+ }
+ yylval.vval = f;
+ return VAL;
+}
+
+func
+main()
+{
+ var file string;
+
+ flag.BoolVar(&vflag, "v", false, "verbose");
+
+ flag.Parse();
+
+ file = "units";
+ if flag.NArg() > 0 {
+ file = flag.Arg(0);
+ }
+
+ f,err := os.Open(file, os.O_RDONLY, 0);
+ if err != nil {
+ fmt.Printf("error opening %v: %v", file, err);
+ os.Exit(1);
+ }
+ fi = bufio.NewReader(f);
+
+ one.vval = 1;
+
+ /*
+ * read the 'units' file to
+ * develope a database
+ */
+ lineno = 0;
+ for {
+ lineno++;
+ if readline() {
+ break;
+ }
+ if len(line) == 0 || line[0] == '/' {
+ continue;
+ }
+ peekrune = ':';
+ Parse();
+ }
+
+ /*
+ * read the console to
+ * print ratio of pairs
+ */
+ fi = bufio.NewReader(os.NewFile(0, "stdin"));
+
+ lineno = 0;
+ for {
+ if (lineno & 1) != 0 {
+ fmt.Printf("you want: ");
+ } else
+ fmt.Printf("you have: ");
+ if readline() {
+ break;
+ }
+ peekrune = '?';
+ nerrors = 0;
+ Parse();
+ if nerrors != 0 {
+ continue;
+ }
+ if (lineno & 1) != 0 {
+ if specialcase(&retnode, &retnode2, &retnode1) {
+ fmt.Printf("\tis %v\n", &retnode);
+ } else {
+ div(&retnode, &retnode2, &retnode1);
+ fmt.Printf("\t* %v\n", &retnode);
+ div(&retnode, &retnode1, &retnode2);
+ fmt.Printf("\t/ %v\n", &retnode);
+ }
+ } else
+ retnode2 = retnode1;
+ lineno++;
+ }
+ fmt.Printf("\n");
+ os.Exit(0);
+}
+
+/*
+ * all characters that have some
+ * meaning. rest are usable as names
+ */
+func
+ralpha(c int) bool
+{
+ switch c {
+ case 0, '+', '-', '*', '/', '[', ']', '(', ')',
+ '^', ':', '?', ' ', '\t', '.', '|', '#',
+ '×', '÷', '¹', 'ⁱ', '²', '', '³', '':
+ return false;
+ }
+ return true;
+}
+
+/*
+ * number forming character
+ */
+func
+rdigit(c int) bool
+{
+ switch c {
+ case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
+ '.', 'e', '+', '-':
+ return true;
+ }
+ return false;
+}
+
+func
+Error(s string, v ...)
+{
+
+ /*
+ * hack to intercept message from yaccpar
+ */
+ if s == "syntax error" {
+ Error("syntax error, last name: %v", sym);
+ return;
+ }
+ fmt.Printf("%v: %v\n\t", lineno, line);
+ fmt.Printf(s, v);
+ fmt.Printf("\n");
+
+ nerrors++;
+ if nerrors > 5 {
+ fmt.Printf("too many errors\n");
+ os.Exit(1);
+ }
+}
+
+func
+add(c,a,b *Node)
+{
+ var i int;
+ var d int8;
+
+ for i=0; i<Ndim; i++ {
+ d = a.dim[i];
+ c.dim[i] = d;
+ if d != b.dim[i] {
+ Error("add must be like units");
+ }
+ }
+ c.vval = fadd(a.vval, b.vval);
+}
+
+func
+sub(c,a,b *Node)
+{
+ var i int;
+ var d int8;
+
+ for i=0; i<Ndim; i++ {
+ d = a.dim[i];
+ c.dim[i] = d;
+ if d != b.dim[i] {
+ Error("sub must be like units");
+ }
+ }
+ c.vval = fadd(a.vval, -b.vval);
+}
+
+func
+mul(c,a,b *Node)
+{
+ var i int;
+
+ for i=0; i<Ndim; i++ {
+ c.dim[i] = a.dim[i] + b.dim[i];
+ }
+ c.vval = fmul(a.vval, b.vval);
+}
+
+func
+div(c,a,b *Node)
+{
+ var i int;
+
+ for i=0; i<Ndim; i++ {
+ c.dim[i] = a.dim[i] - b.dim[i];
+ }
+ c.vval = fdiv(a.vval, b.vval);
+}
+
+func
+xpn(c,a *Node, b int)
+{
+ var i int;
+
+ *c = one;
+ if b < 0 {
+ b = -b;
+ for i=0; i<b; i++ {
+ div(c, c, a);
+ }
+ } else
+ for i=0; i<b; i++ {
+ mul(c, c, a);
+ }
+}
+
+func
+specialcase(c,a,b *Node) bool
+{
+ var i int;
+ var d, d1, d2 int8;
+
+ d1 = 0;
+ d2 = 0;
+ for i=1; i<Ndim; i++ {
+ d = a.dim[i];
+ if d != 0 {
+ if d != 1 || d1 != 0 {
+ return false;
+ }
+ d1 = int8(i);
+ }
+ d = b.dim[i];
+ if d != 0 {
+ if d != 1 || d2 != 0 {
+ return false;
+ }
+ d2 = int8(i);
+ }
+ }
+ if d1 == 0 || d2 == 0 {
+ return false;
+ }
+
+ if fund[d1].name == "°C" && fund[d2].name == "°F" &&
+ b.vval == 1 {
+ for ll:=0; ll<len(c.dim); ll++ {
+ c.dim[ll] = b.dim[ll];
+ }
+ c.vval = a.vval * 9. / 5. + 32.;
+ return true;
+ }
+
+ if fund[d1].name == "°F" && fund[d2].name == "°C" &&
+ b.vval == 1 {
+ for ll:=0; ll<len(c.dim); ll++ {
+ c.dim[ll] = b.dim[ll];
+ }
+ c.vval = (a.vval - 32.) * 5. / 9.;
+ return true;
+ }
+ return false;
+}
+
+func
+printdim(str string, d, n int) string
+{
+ var v *Var;
+
+ if n != 0 {
+ v = fund[d];
+ if v != nil {
+ str += fmt.Sprintf("%v", v.name);
+ } else
+ str += fmt.Sprintf("[%d]", d);
+ switch n {
+ case 1:
+ break;
+ case 2:
+ str += "²";
+ case 3:
+ str += "³";
+ default:
+ str += fmt.Sprintf("^%d", n);
+ }
+ }
+ return str;
+}
+
+func (n Node)
+String() string
+{
+ var str string;
+ var f, i, d int;
+
+ str = fmt.Sprintf("%.7e ", n.vval);
+
+ f = 0;
+ for i=1; i<Ndim; i++ {
+ d = int(n.dim[i]);
+ if d > 0 {
+ str = printdim(str, i, d);
+ } else
+ if d < 0 {
+ f = 1;
+ }
+ }
+
+ if f != 0 {
+ str += " /";
+ for i=1; i<Ndim; i++ {
+ d = int(n.dim[i]);
+ if d < 0 {
+ str = printdim(str, i, -d);
+ }
+ }
+ }
+
+ return str;
+}
+
+func (v *Var)
+String() string
+{
+ var str string;
+ str = fmt.Sprintf("%v %v", v.name, v.node);
+ return str;
+}
+
+func
+readline() bool
+{
+ s,err := fi.ReadString('\n');
+ if err != nil {
+ return true;
+ }
+ line = s;
+ linep = 0;
+ return false;
+}
+
+func
+getrune() int
+{
+ var c,n int;
+
+ if linep >= len(line) {
+ return 0;
+ }
+ c,n = utf8.DecodeRuneInString(line[linep:len(line)]);
+ linep += n;
+ if c == '\n' {
+ c = 0;
+ }
+ return c;
+}
+
+var symmap = make(map[string]*Var); // symbol table
+
+func
+lookup(f int) *Var
+{
+ var p float64;
+ var w *Var;
+
+ v,ok := symmap[sym];
+ if ok {
+ return v;
+ }
+ if f != 0 {
+ return nil;
+ }
+ v = new(Var);
+ v.name = sym;
+ symmap[sym] = v;
+
+ p = 1;
+ for {
+ p = fmul(p, pname());
+ if p == 0 {
+ break;
+ }
+ w = lookup(1);
+ if w != nil {
+ v.node = w.node;
+ v.node.vval = fmul(v.node.vval, p);
+ break;
+ }
+ }
+ return v;
+}
+
+type Prefix
+struct
+{
+ vval float64;
+ name string;
+}
+
+var prefix = []Prefix { // prefix table
+ Prefix { 1e-24, "yocto" },
+ Prefix { 1e-21, "zepto" },
+ Prefix { 1e-18, "atto" },
+ Prefix { 1e-15, "femto" },
+ Prefix { 1e-12, "pico" },
+ Prefix { 1e-9, "nano" },
+ Prefix { 1e-6, "micro" },
+ Prefix { 1e-6, "μ" },
+ Prefix { 1e-3, "milli" },
+ Prefix { 1e-2, "centi" },
+ Prefix { 1e-1, "deci" },
+ Prefix { 1e1, "deka" },
+ Prefix { 1e2, "hecta" },
+ Prefix { 1e2, "hecto" },
+ Prefix { 1e3, "kilo" },
+ Prefix { 1e6, "mega" },
+ Prefix { 1e6, "meg" },
+ Prefix { 1e9, "giga" },
+ Prefix { 1e12, "tera" },
+ Prefix { 1e15, "peta" },
+ Prefix { 1e18, "exa" },
+ Prefix { 1e21, "zetta" },
+ Prefix { 1e24, "yotta" }
+}
+
+func
+pname() float64
+{
+ var i, j, n int;
+ var s string;
+
+ /*
+ * rip off normal prefixs
+ */
+ n = len(sym);
+ for i=0; i<len(prefix); i++ {
+ s = prefix[i].name;
+ j = len(s);
+ if j < n && sym[0:j] == s {
+ sym = sym[j:n];
+ return prefix[i].vval;
+ }
+ }
+
+ /*
+ * rip off 's' suffixes
+ */
+ if n > 2 && sym[n-1] == 's' {
+ sym = sym[0:n-1];
+ return 1;
+ }
+
+ return 0;
+}
+
+
+// careful multiplication
+// exponents (log) are checked before multiply
+func
+fmul(a, b float64) float64
+{
+ var l float64;
+
+ if b <= 0 {
+ if b == 0 {
+ return 0;
+ }
+ l = math.Log(-b);
+ } else
+ l = math.Log(b);
+
+ if a <= 0 {
+ if a == 0 {
+ return 0;
+ }
+ l += math.Log(-a);
+ } else
+ l += math.Log(a);
+
+ if l > Maxe {
+ Error("overflow in multiply");
+ return 1;
+ }
+ if l < -Maxe {
+ Error("underflow in multiply");
+ return 0;
+ }
+ return a*b;
+}
+
+// careful division
+// exponents (log) are checked before divide
+func
+fdiv(a, b float64) float64
+{
+ var l float64;
+
+ if b <= 0 {
+ if b == 0 {
+ Error("division by zero: %v %v", a, b);
+ return 1;
+ }
+ l = math.Log(-b);
+ } else
+ l = math.Log(b);
+
+ if a <= 0 {
+ if a == 0 {
+ return 0;
+ }
+ l -= math.Log(-a);
+ } else
+ l -= math.Log(a);
+
+ if l < -Maxe {
+ Error("overflow in divide");
+ return 1;
+ }
+ if l > Maxe {
+ Error("underflow in divide");
+ return 0;
+ }
+ return a/b;
+}
+
+func
+fadd(a, b float64) float64
+{
+ return a + b;
+}