Change goyacc to be reentrant.
Instead of calling the package scope Lex function,
Parse now takes an argument which is used to
do the lexing.
I reverted to having the generated switch
code inside Parse rather than a separate function because
the function needs 7 arguments or a context structure,
which seems unnecessary.
I used yyrun(), not the original $A so that
it's possible to run the backquoted code through gofmt.
R=rsc, ken2, ken3
CC=golang-dev
https://golang.org/cl/879041
diff --git a/src/cmd/goyacc/doc.go b/src/cmd/goyacc/doc.go
index a3cf075..eea70ad 100644
--- a/src/cmd/goyacc/doc.go
+++ b/src/cmd/goyacc/doc.go
@@ -19,5 +19,18 @@
the Unix tool units, also written in Go and largely transliterated
from the Plan 9 C version.
+The generated parser is reentrant. Parse expects to be given an
+argument that conforms to the following interface:
+
+ type yyLexer interface {
+ Lex(lval *yySymType) int
+ }
+
+Lex should return the token identifier, and place other token
+information in lval (which replaces the usual yylval).
+
+Code inside the parser may refer to the variable yylex
+which holds the yyLexer passed to Parse.
+
*/
package documentation
diff --git a/src/cmd/goyacc/goyacc.go b/src/cmd/goyacc/goyacc.go
index 31ab32c..118d277 100644
--- a/src/cmd/goyacc/goyacc.go
+++ b/src/cmd/goyacc/goyacc.go
@@ -49,6 +49,8 @@
"fmt"
"bufio"
"os"
+ "strings"
+ "bytes"
)
// the following are adjustable
@@ -104,7 +106,7 @@
)
// output parser flags
-const YYFLAG = -1000
+const yyFlag = -1000
// parse tokens
const (
@@ -147,8 +149,9 @@
// I/O descriptors
var finput *bufio.Reader // input file
var stderr *bufio.Writer
-var ftable *bufio.Writer // y.go file
-var foutput *bufio.Writer // y.output file
+var ftable *bufio.Writer // y.go file
+var fcode = &bytes.Buffer{} // saved code
+var foutput *bufio.Writer // y.output file
var oflag string // -o [y.go] - y.go file
var vflag string // -v [y.output] - y.output file
@@ -503,22 +506,20 @@
}
// put out names of token names
- fmt.Fprintf(ftable, "var\tToknames\t =[]string {\n")
+ fmt.Fprintf(ftable, "var\tyyToknames\t =[]string {\n")
for i := TOKSTART; i <= ntokens; i++ {
fmt.Fprintf(ftable, "\t\"%v\",\n", tokset[i].name)
}
fmt.Fprintf(ftable, "}\n")
// put out names of state names
- fmt.Fprintf(ftable, "var\tStatenames\t =[]string {\n")
+ fmt.Fprintf(ftable, "var\tyyStatenames\t =[]string {\n")
// for i:=TOKSTART; i<=ntokens; i++ {
// fmt.Fprintf(ftable, "\t\"%v\",\n", tokset[i].name);
// }
fmt.Fprintf(ftable, "}\n")
- fmt.Fprintf(ftable, "\nfunc\n")
- fmt.Fprintf(ftable, "yyrun(p int, yypt int) {\n")
- fmt.Fprintf(ftable, "switch p {\n")
+ fmt.Fprintf(fcode, "switch yynt {\n")
moreprod()
prdptr[0] = []int{NTBASE, start, 1, 0}
@@ -589,7 +590,7 @@
break
}
levprd[nprod] |= ACTFLAG
- fmt.Fprintf(ftable, "\ncase %v:", nprod)
+ fmt.Fprintf(fcode, "\ncase %v:", nprod)
cpyact(curprod, mem)
// action within rule...
@@ -646,8 +647,8 @@
if tempty != nontrst[curprod[0]-NTBASE].value {
error("default action causes potential type clash")
}
- fmt.Fprintf(ftable, "\ncase %v:", nprod)
- fmt.Fprintf(ftable, "\n\tYYVAL.%v = YYS[yypt-0].%v;",
+ fmt.Fprintf(fcode, "\ncase %v:", nprod)
+ fmt.Fprintf(fcode, "\n\tYYVAL.%v = YYS[yypt-0].%v;",
typeset[tempty], typeset[tempty])
}
moreprod()
@@ -663,12 +664,11 @@
// dump out the prefix code
//
- fmt.Fprintf(ftable, "\n\t}")
- fmt.Fprintf(ftable, "\n}\n")
+ fmt.Fprintf(fcode, "\n\t}")
- fmt.Fprintf(ftable, "const YYEOFCODE = 1\n")
- fmt.Fprintf(ftable, "const YYERRCODE = 2\n")
- fmt.Fprintf(ftable, "const YYMAXDEPTH = %v\n", stacksize)
+ fmt.Fprintf(ftable, "const yyEofCode = 1\n")
+ fmt.Fprintf(ftable, "const yyErrCode = 2\n")
+ fmt.Fprintf(ftable, "const yyMaxDepth = %v\n", stacksize)
//
// copy any postfix code
@@ -682,7 +682,7 @@
if c == EOF {
break
}
- putrune(ftable, c)
+ ftable.WriteRune(c)
}
}
}
@@ -1034,7 +1034,7 @@
if !lflag {
fmt.Fprintf(ftable, "\n//line %v %v\n", lineno, infile)
}
- fmt.Fprintf(ftable, "type\tYYSTYPE\tstruct")
+ fmt.Fprintf(ftable, "type\tyySymType\tstruct")
level := 0
@@ -1044,7 +1044,7 @@
if c == EOF {
error("EOF encountered while processing %%union")
}
- putrune(ftable, c)
+ ftable.WriteRune(c)
switch c {
case '\n':
lineno++
@@ -1061,9 +1061,6 @@
}
}
fmt.Fprintf(ftable, "\n")
- fmt.Fprintf(ftable, "var\tyylval\tYYSTYPE\n")
- fmt.Fprintf(ftable, "var\tYYVAL\tYYSTYPE\n")
- fmt.Fprintf(ftable, "var\tYYS\t[%v]YYSTYPE\n", stacksize)
}
//
@@ -1086,9 +1083,9 @@
if c == '}' {
return
}
- putrune(ftable, '%')
+ ftable.WriteRune('%')
}
- putrune(ftable, c)
+ ftable.WriteRune(c)
if c == '\n' {
lineno++
}
@@ -1098,74 +1095,6 @@
error("eof before %%}")
}
-//func
-//addcode(k int, s string)
-//{
-// for i := 0; i < len(s); i++ {
-// addcodec(k, int(s[i]));
-// }
-//}
-
-//func
-//addcodec(k, c int)
-//{
-// if codehead == nil || k != codetail.kind || codetail.ndata >= NCode {
-// cd := new(Code);
-// cd.kind = k;
-// cd.data = make([]byte, NCode+UTFmax);
-// cd.ndata = 0;
-// cd.next = nil;
-//
-// if codehead == nil {
-// codehead = cd;
-// } else
-// codetail.next = cd;
-// codetail = cd;
-// }
-//
-////!! codetail.ndata += sys->char2byte(c, codetail.data, codetail.ndata);
-//}
-
-//func
-//dumpcode(til int)
-//{
-// for ; codehead != nil; codehead = codehead.next {
-// if codehead.kind == til {
-// return;
-// }
-// if write(ftable, codehead.data, codehead.ndata) != codehead.ndata {
-// error("can't write output file");
-// }
-// }
-//}
-
-//
-// write out the module declaration and any token info
-//
-//func
-//dumpmod()
-//{
-//
-// for ; codehead != nil; codehead = codehead.next {
-// if codehead.kind != CodeMod {
-// break;
-// }
-// if write(ftable, codehead.data, codehead.ndata) != codehead.ndata {
-// error("can't write output file");
-// }
-// }
-//
-// for i:=TOKSTART; i<=ntokens; i++ {
-// // non-literals
-// c := tokset[i].name[0];
-// if c != ' ' && c != '$' {
-// fmt.Fprintf(ftable, "vonst %v %v\n",
-// tokset[i].name, tokset[i].value);
-// }
-// }
-//
-//}
-
//
// skip over comments
// skipcom is called after reading a '/'
@@ -1229,7 +1158,7 @@
func cpyact(curprod []int, max int) {
if !lflag {
- fmt.Fprintf(ftable, "\n//line %v %v\n", lineno, infile)
+ fmt.Fprintf(fcode, "\n//line %v %v\n", lineno, infile)
}
lno := lineno
@@ -1243,14 +1172,14 @@
switch c {
case ';':
if brac == 0 {
- putrune(ftable, c)
+ ftable.WriteRune(c)
return
}
case '{':
if brac == 0 {
}
- putrune(ftable, '\t')
+ ftable.WriteRune('\t')
brac++
case '$':
@@ -1268,14 +1197,14 @@
c = getrune(finput)
}
if c == '$' {
- fmt.Fprintf(ftable, "YYVAL")
+ fmt.Fprintf(fcode, "YYVAL")
// put out the proper tag...
if ntypes != 0 {
if tok < 0 {
tok = fdtype(curprod[0])
}
- fmt.Fprintf(ftable, ".%v", typeset[tok])
+ fmt.Fprintf(fcode, ".%v", typeset[tok])
}
continue loop
}
@@ -1322,14 +1251,14 @@
error("$name or $name@number not found")
}
} else {
- putrune(ftable, '$')
+ fcode.WriteRune('$')
if s < 0 {
- putrune(ftable, '-')
+ fcode.WriteRune('-')
}
ungetrune(finput, c)
continue loop
}
- fmt.Fprintf(ftable, "YYS[yypt-%v]", max-j-1)
+ fmt.Fprintf(fcode, "YYS[yypt-%v]", max-j-1)
// put out the proper tag
if ntypes != 0 {
@@ -1339,7 +1268,7 @@
if tok < 0 {
tok = fdtype(curprod[j])
}
- fmt.Fprintf(ftable, ".%v", typeset[tok])
+ fmt.Fprintf(fcode, ".%v", typeset[tok])
}
continue loop
@@ -1348,7 +1277,7 @@
if brac != 0 {
break
}
- putrune(ftable, c)
+ fcode.WriteRune(c)
return
case '/':
@@ -1358,8 +1287,8 @@
break
}
// a comment
- putrune(ftable, c)
- putrune(ftable, nc)
+ fcode.WriteRune(c)
+ fcode.WriteRune(nc)
c = getrune(finput)
for c != EOF {
switch {
@@ -1371,14 +1300,14 @@
case c == '*' && nc == '*': // end of /* comment?
nnc := getrune(finput)
if nnc == '/' {
- putrune(ftable, '*')
- putrune(ftable, '/')
+ fcode.WriteRune('*')
+ fcode.WriteRune('/')
c = getrune(finput)
break swt
}
ungetrune(finput, nnc)
}
- putrune(ftable, c)
+ fcode.WriteRune(c)
c = getrune(finput)
}
error("EOF inside comment")
@@ -1386,11 +1315,11 @@
case '\'', '"':
// character string or constant
match := c
- putrune(ftable, c)
+ fcode.WriteRune(c)
c = getrune(finput)
for c != EOF {
if c == '\\' {
- putrune(ftable, c)
+ fcode.WriteRune(c)
c = getrune(finput)
if c == '\n' {
lineno++
@@ -1401,7 +1330,7 @@
if c == '\n' {
error("newline in string or char const")
}
- putrune(ftable, c)
+ fcode.WriteRune(c)
c = getrune(finput)
}
error("EOF in string or character constant")
@@ -1414,7 +1343,7 @@
lineno++
}
- putrune(ftable, c)
+ fcode.WriteRune(c)
}
}
@@ -2137,7 +2066,7 @@
func output() {
var c, u, v int
- fmt.Fprintf(ftable, "var\tYYEXCA = []int {\n")
+ fmt.Fprintf(ftable, "var\tyyExca = []int {\n")
noset := mkset()
@@ -2210,10 +2139,10 @@
}
fmt.Fprintf(ftable, "}\n")
- fmt.Fprintf(ftable, "const\tYYNPROD\t= %v\n", nprod)
- fmt.Fprintf(ftable, "const\tYYPRIVATE\t= %v\n", PRIVATE)
- fmt.Fprintf(ftable, "var\tYYTOKENNAMES []string\n")
- fmt.Fprintf(ftable, "var\tYYSTATES []string\n")
+ fmt.Fprintf(ftable, "const\tyyNprod\t= %v\n", nprod)
+ fmt.Fprintf(ftable, "const\tyyPrivate\t= %v\n", PRIVATE)
+ fmt.Fprintf(ftable, "var\tyyTokenNames []string\n")
+ fmt.Fprintf(ftable, "var\tyyStates []string\n")
}
//
@@ -2616,7 +2545,7 @@
if tystate[i] == 0 && adb > 1 {
fmt.Fprintf(ftable, "State %v: null\n", i)
}
- indgo[i] = YYFLAG
+ indgo[i] = yyFlag
}
i = nxti()
@@ -2636,7 +2565,7 @@
for i = 0; i < 10; i++ {
fmt.Fprintf(ftable, "%v ", amem[p+i])
}
- putrune(ftable, '\n')
+ ftable.WriteRune('\n')
}
}
@@ -2788,10 +2717,10 @@
// write out the optimized parser
//
func aoutput() {
- fmt.Fprintf(ftable, "const\tYYLAST\t= %v\n", maxa+1)
- arout("YYACT", amem, maxa+1)
- arout("YYPACT", indgo, nstate)
- arout("YYPGO", pgo, nnonter+1)
+ fmt.Fprintf(ftable, "const\tyyLast\t= %v\n", maxa+1)
+ arout("yyAct", amem, maxa+1)
+ arout("yyPact", indgo, nstate)
+ arout("yyPgo", pgo, nnonter+1)
}
//
@@ -2800,7 +2729,7 @@
func others() {
var i, j int
- arout("YYR1", levprd, nprod)
+ arout("yyR1", levprd, nprod)
aryfil(temp1, nprod, 0)
//
@@ -2809,7 +2738,7 @@
for i = 1; i < nprod; i++ {
temp1[i] = len(prdptr[i]) - 2
}
- arout("YYR2", temp1, nprod)
+ arout("yyR2", temp1, nprod)
aryfil(temp1, nstate, -1000)
for i = 0; i <= ntokens; i++ {
@@ -2822,8 +2751,8 @@
temp1[j] = -i
}
}
- arout("YYCHK", temp1, nstate)
- arout("YYDEF", defact, nstate)
+ arout("yyChk", temp1, nstate)
+ arout("yyDef", defact, nstate)
// put out token translation tables
// table 1 has 0-256
@@ -2848,7 +2777,7 @@
temp1[i] = YYLEXUNK
}
}
- arout("YYTOK1", temp1, c+1)
+ arout("yyTok1", temp1, c+1)
// table 2 has PRIVATE-PRIVATE+256
aryfil(temp1, 256, 0)
@@ -2867,10 +2796,10 @@
}
}
}
- arout("YYTOK2", temp1, c+1)
+ arout("yyTok2", temp1, c+1)
// table 3 has everything else
- fmt.Fprintf(ftable, "var\tYYTOK3\t= []int {\n")
+ fmt.Fprintf(ftable, "var\tyyTok3\t= []int {\n")
c = 0
for i = 1; i <= ntokens; i++ {
j = tokset[i].value
@@ -2884,7 +2813,7 @@
fmt.Fprintf(ftable, "%4d,%4d,", j, i)
c++
if c%5 == 0 {
- putrune(ftable, '\n')
+ ftable.WriteRune('\n')
}
}
fmt.Fprintf(ftable, "%4d,\n };\n", 0)
@@ -2892,22 +2821,25 @@
// copy parser text
c = getrune(finput)
for c != EOF {
- putrune(ftable, c)
+ ftable.WriteRune(c)
c = getrune(finput)
}
+ parts := strings.Split(yaccpar, "yyrun()", 2)
// copy yaccpar
- fmt.Fprintf(ftable, "%v", yaccpar)
+ fmt.Fprintf(ftable, "%v", parts[0])
+ ftable.Write(fcode.Bytes())
+ fmt.Fprintf(ftable, "%v", parts[1])
}
func arout(s string, v []int, n int) {
fmt.Fprintf(ftable, "var\t%v\t= []int {\n", s)
for i := 0; i < n; i++ {
if i%10 == 0 {
- putrune(ftable, '\n')
+ ftable.WriteRune('\n')
}
fmt.Fprintf(ftable, "%4d", v[i])
- putrune(ftable, ',')
+ ftable.WriteRune(',')
}
fmt.Fprintf(ftable, "\n};\n")
}
@@ -2978,7 +2910,7 @@
}
func usage() {
- fmt.Fprintf(stderr, "usage: gacc [-o output] [-v parsetable] input\n")
+ fmt.Fprintf(stderr, "usage: goyacc [-o output] [-v parsetable] input\n")
exit(1)
}
@@ -3144,224 +3076,228 @@
var yaccpar = `
/* parser for yacc output */
-var Nerrs = 0 /* number of errors */
-var Errflag = 0 /* error recovery flag */
-var Debug = 0
-const YYFLAG = -1000
+var yyDebug = 0
-func
-Tokname(yyc int) string {
- if yyc > 0 && yyc <= len(Toknames) {
- if Toknames[yyc-1] != "" {
- return Toknames[yyc-1];
- }
- }
- return fmt.Sprintf("tok-%v", yyc);
+type yyLexer interface {
+ Lex(lval *yySymType) int
}
-func
-Statname(yys int) string {
- if yys >= 0 && yys < len(Statenames) {
- if Statenames[yys] != "" {
- return Statenames[yys];
+const yyFlag = -1000
+
+func yyTokname(yyc int) string {
+ if yyc > 0 && yyc <= len(yyToknames) {
+ if yyToknames[yyc-1] != "" {
+ return yyToknames[yyc-1]
}
}
- return fmt.Sprintf("state-%v", yys);
+ return fmt.Sprintf("tok-%v", yyc)
}
-func
-lex1() int {
- var yychar int;
- var c int;
+func yyStatname(yys int) string {
+ if yys >= 0 && yys < len(yyStatenames) {
+ if yyStatenames[yys] != "" {
+ return yyStatenames[yys]
+ }
+ }
+ return fmt.Sprintf("state-%v", yys)
+}
- yychar = Lex();
+func yylex1(yylex yyLexer, lval *yySymType) int {
+ var yychar int
+ var c int
+
+ yychar = yylex.Lex(lval)
if yychar <= 0 {
- c = YYTOK1[0];
- goto out;
+ c = yyTok1[0]
+ goto out
}
- if yychar < len(YYTOK1) {
- c = YYTOK1[yychar];
- goto out;
+ if yychar < len(yyTok1) {
+ c = yyTok1[yychar]
+ goto out
}
- if yychar >= YYPRIVATE {
- if yychar < YYPRIVATE+len(YYTOK2) {
- c = YYTOK2[yychar-YYPRIVATE];
- goto out;
+ if yychar >= yyPrivate {
+ if yychar < yyPrivate+len(yyTok2) {
+ c = yyTok2[yychar-yyPrivate]
+ goto out
}
}
- for i:=0; i<len(YYTOK3); i+=2 {
- c = YYTOK3[i+0];
+ for i := 0; i < len(yyTok3); i += 2 {
+ c = yyTok3[i+0]
if c == yychar {
- c = YYTOK3[i+1];
- goto out;
+ c = yyTok3[i+1]
+ goto out
}
}
- c = 0;
+ c = 0
out:
if c == 0 {
- c = YYTOK2[1]; /* unknown char */
+ c = yyTok2[1] /* unknown char */
}
- if Debug >= 3 {
- fmt.Printf("lex %.4lux %s\n", yychar, Tokname(c));
+ if yyDebug >= 3 {
+ fmt.Printf("lex %.4x %s\n", uint(yychar), yyTokname(c))
}
- return c;
+ return c
}
-func
-Parse() int {
- var yyj, yystate, yyn, yyg, yyxi, yyp int;
- var yychar int;
- var yypt, yynt int;
+func yyParse(yylex yyLexer) int {
+ var yyn int
+ var yylval yySymType
+ var YYVAL yySymType
+ YYS := make([]yySymType, yyMaxDepth)
- yystate = 0;
- yychar = -1;
- Nerrs = 0;
- Errflag = 0;
- yyp = -1;
- goto yystack;
+ Nerrs := 0 /* number of errors */
+ Errflag := 0 /* error recovery flag */
+ yystate := 0
+ yychar := -1
+ yyp := -1
+ goto yystack
ret0:
- return 0;
+ return 0
ret1:
- return 1;
+ return 1
yystack:
/* put a state and value onto the stack */
- if Debug >= 4 {
- fmt.Printf("char %v in %v", Tokname(yychar), Statname(yystate));
+ if yyDebug >= 4 {
+ fmt.Printf("char %v in %v", yyTokname(yychar), yyStatname(yystate))
}
- yyp++;
+ yyp++
if yyp >= len(YYS) {
- Error("yacc stack overflow");
- goto ret1;
+ nyys := make([]yySymType, len(YYS)*2)
+ copy(nyys, YYS)
+ YYS = nyys
}
- YYS[yyp] = YYVAL;
- YYS[yyp].yys = yystate;
+ YYS[yyp] = YYVAL
+ YYS[yyp].yys = yystate
yynewstate:
- yyn = YYPACT[yystate];
- if yyn <= YYFLAG {
- goto yydefault; /* simple state */
+ yyn = yyPact[yystate]
+ if yyn <= yyFlag {
+ goto yydefault /* simple state */
}
if yychar < 0 {
- yychar = lex1();
+ yychar = yylex1(yylex, &yylval)
}
- yyn += yychar;
- if yyn < 0 || yyn >= YYLAST {
- goto yydefault;
+ yyn += yychar
+ if yyn < 0 || yyn >= yyLast {
+ goto yydefault
}
- yyn = YYACT[yyn];
- if YYCHK[yyn] == yychar { /* valid shift */
- yychar = -1;
- YYVAL = yylval;
- yystate = yyn;
+ yyn = yyAct[yyn]
+ if yyChk[yyn] == yychar { /* valid shift */
+ yychar = -1
+ YYVAL = yylval
+ yystate = yyn
if Errflag > 0 {
- Errflag--;
+ Errflag--
}
- goto yystack;
+ goto yystack
}
yydefault:
/* default state action */
- yyn = YYDEF[yystate];
+ yyn = yyDef[yystate]
if yyn == -2 {
if yychar < 0 {
- yychar = lex1();
+ yychar = yylex1(yylex, &yylval)
}
/* look through exception table */
- for yyxi=0;; yyxi+=2 {
- if YYEXCA[yyxi+0] == -1 && YYEXCA[yyxi+1] == yystate {
- break;
+ yyxi := 0
+ for {
+ if yyExca[yyxi+0] == -1 && yyExca[yyxi+1] == yystate {
+ break
}
+ yyxi += 2
}
- for yyxi += 2;; yyxi += 2 {
- yyn = YYEXCA[yyxi+0];
+ for yyxi += 2; ; yyxi += 2 {
+ yyn = yyExca[yyxi+0]
if yyn < 0 || yyn == yychar {
- break;
+ break
}
}
- yyn = YYEXCA[yyxi+1];
+ yyn = yyExca[yyxi+1]
if yyn < 0 {
- goto ret0;
+ goto ret0
}
}
if yyn == 0 {
/* error ... attempt to resume parsing */
switch Errflag {
- case 0: /* brand new error */
- Error("syntax error");
- Nerrs++;
- if Debug >= 1 {
- fmt.Printf("%s", Statname(yystate));
- fmt.Printf("saw %s\n", Tokname(yychar));
+ case 0: /* brand new error */
+ yyError("syntax error")
+ Nerrs++
+ if yyDebug >= 1 {
+ fmt.Printf("%s", yyStatname(yystate))
+ fmt.Printf("saw %s\n", yyTokname(yychar))
}
- fallthrough;
+ fallthrough
- case 1,2: /* incompletely recovered error ... try again */
- Errflag = 3;
+ case 1, 2: /* incompletely recovered error ... try again */
+ Errflag = 3
/* find a state where "error" is a legal shift action */
for yyp >= len(YYS) {
- yyn = YYPACT[YYS[yyp].yys] + YYERRCODE;
- if yyn >= 0 && yyn < YYLAST {
- yystate = YYACT[yyn]; /* simulate a shift of "error" */
- if YYCHK[yystate] == YYERRCODE {
- goto yystack;
+ yyn = yyPact[YYS[yyp].yys] + yyErrCode
+ if yyn >= 0 && yyn < yyLast {
+ yystate = yyAct[yyn] /* simulate a shift of "error" */
+ if yyChk[yystate] == yyErrCode {
+ goto yystack
}
}
/* the current yyp has no shift onn "error", pop stack */
- if Debug >= 2 {
+ if yyDebug >= 2 {
fmt.Printf("error recovery pops state %d, uncovers %d\n",
- YYS[yyp].yys, YYS[yyp-1].yys );
+ YYS[yyp].yys, YYS[yyp-1].yys)
}
- yyp--;
+ yyp--
}
/* there is no state on the stack with an error shift ... abort */
- goto ret1;
+ goto ret1
- case 3: /* no shift yet; clobber input char */
- if Debug >= 2 {
- fmt.Printf("error recovery discards %s\n", Tokname(yychar));
+ case 3: /* no shift yet; clobber input char */
+ if yyDebug >= 2 {
+ fmt.Printf("error recovery discards %s\n", yyTokname(yychar))
}
- if yychar == YYEOFCODE {
- goto ret1;
+ if yychar == yyEofCode {
+ goto ret1
}
- yychar = -1;
- goto yynewstate; /* try again in the same state */
+ yychar = -1
+ goto yynewstate /* try again in the same state */
}
}
/* reduction by production yyn */
- if Debug >= 2 {
- fmt.Printf("reduce %v in:\n\t%v", yyn, Statname(yystate));
+ if yyDebug >= 2 {
+ fmt.Printf("reduce %v in:\n\t%v", yyn, yyStatname(yystate))
}
- yynt = yyn;
- yypt = yyp;
+ yynt := yyn
+ yypt := yyp
+ _ = yypt // guard against "declared and not used"
- yyp -= YYR2[yyn];
- YYVAL = YYS[yyp+1];
+ yyp -= yyR2[yyn]
+ YYVAL = YYS[yyp+1]
/* consult goto table to find next state */
- yyn = YYR1[yyn];
- yyg = YYPGO[yyn];
- yyj = yyg + YYS[yyp].yys + 1;
+ yyn = yyR1[yyn]
+ yyg := yyPgo[yyn]
+ yyj := yyg + YYS[yyp].yys + 1
- if yyj >= YYLAST {
- yystate = YYACT[yyg];
+ if yyj >= yyLast {
+ yystate = yyAct[yyg]
} else {
- yystate = YYACT[yyj];
- if YYCHK[yystate] != -yyn {
- yystate = YYACT[yyg];
+ yystate = yyAct[yyj]
+ if yyChk[yystate] != -yyn {
+ yystate = yyAct[yyg]
}
}
-
- yyrun(yynt, yypt);
- goto yystack; /* stack new state and value */
+ // dummy call; replaced with literal code
+ yyrun()
+ goto yystack /* stack new state and value */
}
`
diff --git a/src/cmd/goyacc/units.y b/src/cmd/goyacc/units.y
index 9be7fa4..b909d11 100644
--- a/src/cmd/goyacc/units.y
+++ b/src/cmd/goyacc/units.y
@@ -23,48 +23,44 @@
package main
-import
-(
- "flag";
- "fmt";
- "bufio";
- "os";
- "math";
- "strconv";
- "utf8";
+import (
+ "flag"
+ "fmt"
+ "bufio"
+ "os"
+ "math"
+ "strconv"
+ "utf8"
)
-const
-(
- Ndim = 15; // number of dimensions
- Maxe = 695; // log of largest number
+const (
+ Ndim = 15 // number of dimensions
+ Maxe = 695 // log of largest number
)
-type
-Node struct {
- vval float64;
- dim [Ndim]int8;
+type Node struct {
+ vval float64
+ dim [Ndim]int8
}
-type
-Var struct {
- name string;
- node Node;
+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
+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
%}
@@ -217,481 +213,462 @@
}
%%
-func
-Lex() int {
- var c, i int;
+type UnitsLex int
- c = peekrune;
- peekrune = ' ';
+func (l UnitsLex) Lex(yylval *yySymType) int {
+ var c, i int
+
+ c = peekrune
+ peekrune = ' '
loop:
if (c >= '0' && c <= '9') || c == '.' {
- goto numb;
+ goto numb
}
if ralpha(c) {
- goto alpha;
+ goto alpha
}
switch c {
case ' ', '\t':
- c = getrune();
- goto loop;
+ c = getrune()
+ goto loop
case '×':
- return '*';
+ return '*'
case '÷':
- return '/';
+ return '/'
case '¹', 'ⁱ':
- yylval.numb = 1;
- return SUP;
+ yylval.numb = 1
+ return SUP
case '²', '':
- yylval.numb = 2;
- return SUP;
+ yylval.numb = 2
+ return SUP
case '³', '':
- yylval.numb = 3;
- return SUP;
+ yylval.numb = 3
+ return SUP
}
- return c;
+ return c
alpha:
- sym = "";
- for i=0;; i++ {
- sym += string(c);
- c = getrune();
+ sym = ""
+ for i = 0; ; i++ {
+ sym += string(c)
+ c = getrune()
if !ralpha(c) {
- break;
+ break
}
}
- peekrune = c;
- yylval.vvar = lookup(0);
- return VAR;
+ peekrune = c
+ yylval.vvar = lookup(0)
+ return VAR
numb:
- sym = "";
- for i=0;; i++ {
- sym += string(c);
- c = getrune();
+ sym = ""
+ for i = 0; ; i++ {
+ sym += string(c)
+ c = getrune()
if !rdigit(c) {
- break;
+ break
}
}
- peekrune = c;
- f, err := strconv.Atof64(sym);
+ peekrune = c
+ f, err := strconv.Atof64(sym)
if err != nil {
- fmt.Printf("error converting %v", sym);
- f = 0;
+ fmt.Printf("error converting %v\n", sym)
+ f = 0
}
- yylval.vval = f;
- return VAL;
+ yylval.vval = f
+ return VAL
}
-func
-main() {
- var file string;
+func main() {
+ var file string
- flag.BoolVar(&vflag, "v", false, "verbose");
+ flag.BoolVar(&vflag, "v", false, "verbose")
- flag.Parse();
+ flag.Parse()
- file = os.Getenv("GOROOT") + "/src/cmd/goyacc/units.txt";
+ file = os.Getenv("GOROOT") + "/src/cmd/goyacc/units.txt"
if flag.NArg() > 0 {
- file = flag.Arg(0);
+ file = flag.Arg(0)
}
- f,err := os.Open(file, os.O_RDONLY, 0);
+ f, err := os.Open(file, os.O_RDONLY, 0)
if err != nil {
- fmt.Printf("error opening %v: %v", file, err);
- os.Exit(1);
+ fmt.Printf("error opening %v: %v\n", file, err)
+ os.Exit(1)
}
- fi = bufio.NewReader(f);
+ fi = bufio.NewReader(f)
- one.vval = 1;
+ one.vval = 1
/*
* read the 'units' file to
* develope a database
*/
- lineno = 0;
+ lineno = 0
for {
- lineno++;
+ lineno++
if readline() {
- break;
+ break
}
if len(line) == 0 || line[0] == '/' {
- continue;
+ continue
}
- peekrune = ':';
- Parse();
+ peekrune = ':'
+ yyParse(UnitsLex(0))
}
/*
* read the console to
* print ratio of pairs
*/
- fi = bufio.NewReader(os.NewFile(0, "stdin"));
+ fi = bufio.NewReader(os.NewFile(0, "stdin"))
- lineno = 0;
+ lineno = 0
for {
if (lineno & 1) != 0 {
- fmt.Printf("you want: ");
- } else
- fmt.Printf("you have: ");
- if readline() {
- break;
+ fmt.Printf("you want: ")
+ } else {
+ fmt.Printf("you have: ")
}
- peekrune = '?';
- nerrors = 0;
- Parse();
+ if readline() {
+ break
+ }
+ peekrune = '?'
+ nerrors = 0
+ yyParse(UnitsLex(0))
if nerrors != 0 {
- continue;
+ continue
}
if (lineno & 1) != 0 {
if specialcase(&retnode, &retnode2, &retnode1) {
- fmt.Printf("\tis %v\n", &retnode);
+ 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);
+ div(&retnode, &retnode2, &retnode1)
+ fmt.Printf("\t* %v\n", &retnode)
+ div(&retnode, &retnode1, &retnode2)
+ fmt.Printf("\t/ %v\n", &retnode)
}
- } else
- retnode2 = retnode1;
- lineno++;
+ } else {
+ retnode2 = retnode1
+ }
+ lineno++
}
- fmt.Printf("\n");
- os.Exit(0);
+ fmt.Printf("\n")
+ os.Exit(0)
}
/*
* all characters that have some
* meaning. rest are usable as names
*/
-func
-ralpha(c int) bool {
+func ralpha(c int) bool {
switch c {
- case 0, '+', '-', '*', '/', '[', ']', '(', ')',
+ case 0, '+', '-', '*', '/', '[', ']', '(', ')',
'^', ':', '?', ' ', '\t', '.', '|', '#',
'×', '÷', '¹', 'ⁱ', '²', '', '³', '':
- return false;
+ return false
}
- return true;
+ return true
}
/*
* number forming character
*/
-func
-rdigit(c int) bool {
+func rdigit(c int) bool {
switch c {
- case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
+ case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'.', 'e', '+', '-':
- return true;
+ return true
}
- return false;
+ return false
}
-func
-Error(s string, v ...interface{}) {
+func yyError(s string) {
+ Error("syntax error, last name: %v", sym)
+}
- /*
- * 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");
+func Error(s string, v ...interface{}) {
+ fmt.Printf("%v: %v\n\t", lineno, line)
+ fmt.Printf(s, v)
+ fmt.Printf("\n")
- nerrors++;
+ nerrors++
if nerrors > 5 {
- fmt.Printf("too many errors\n");
- os.Exit(1);
+ fmt.Printf("too many errors\n")
+ os.Exit(1)
}
}
-func
-add(c,a,b *Node) {
- var i int;
- var d int8;
+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;
+ 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");
+ Error("add must be like units")
}
}
- c.vval = fadd(a.vval, b.vval);
+ c.vval = fadd(a.vval, b.vval)
}
-func
-sub(c,a,b *Node) {
- var i int;
- var d int8;
+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;
+ 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");
+ Error("sub must be like units")
}
}
- c.vval = fadd(a.vval, -b.vval);
+ c.vval = fadd(a.vval, -b.vval)
}
-func
-mul(c,a,b *Node) {
- var i int;
+func mul(c, a, b *Node) {
+ var i int
- for i=0; i<Ndim; i++ {
- c.dim[i] = a.dim[i] + b.dim[i];
+ for i = 0; i < Ndim; i++ {
+ c.dim[i] = a.dim[i] + b.dim[i]
}
- c.vval = fmul(a.vval, b.vval);
+ c.vval = fmul(a.vval, b.vval)
}
-func
-div(c,a,b *Node) {
- var i int;
+func div(c, a, b *Node) {
+ var i int
- for i=0; i<Ndim; i++ {
- c.dim[i] = a.dim[i] - b.dim[i];
+ for i = 0; i < Ndim; i++ {
+ c.dim[i] = a.dim[i] - b.dim[i]
}
- c.vval = fdiv(a.vval, b.vval);
+ c.vval = fdiv(a.vval, b.vval)
}
-func
-xpn(c,a *Node, b int) {
- var i int;
+func xpn(c, a *Node, b int) {
+ var i int
- *c = one;
+ *c = one
if b < 0 {
- b = -b;
- for i=0; i<b; i++ {
- div(c, c, a);
+ b = -b
+ for i = 0; i < b; i++ {
+ div(c, c, a)
}
- } else
- for i=0; i<b; i++ {
- mul(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;
+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];
+ d1 = 0
+ d2 = 0
+ for i = 1; i < Ndim; i++ {
+ d = a.dim[i]
if d != 0 {
if d != 1 || d1 != 0 {
- return false;
+ return false
}
- d1 = int8(i);
+ d1 = int8(i)
}
- d = b.dim[i];
+ d = b.dim[i]
if d != 0 {
if d != 1 || d2 != 0 {
- return false;
+ return false
}
- d2 = int8(i);
+ d2 = int8(i)
}
}
if d1 == 0 || d2 == 0 {
- return false;
+ 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];
+ 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;
+ 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];
+ 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;
+ c.vval = (a.vval - 32.) * 5. / 9.
+ return true
}
- return false;
+ return false
}
-func
-printdim(str string, d, n int) string {
- var v *Var;
+func printdim(str string, d, n int) string {
+ var v *Var
if n != 0 {
- v = fund[d];
+ v = fund[d]
if v != nil {
- str += fmt.Sprintf("%v", v.name);
- } else
- str += fmt.Sprintf("[%d]", d);
+ str += fmt.Sprintf("%v", v.name)
+ } else {
+ str += fmt.Sprintf("[%d]", d)
+ }
switch n {
case 1:
- break;
+ break
case 2:
- str += "²";
+ str += "²"
case 3:
- str += "³";
+ str += "³"
default:
- str += fmt.Sprintf("^%d", n);
+ str += fmt.Sprintf("^%d", n)
}
}
- return str;
+ return str
}
-func
-(n Node) String() string {
- var str string;
- var f, i, d int;
+func (n Node) String() string {
+ var str string
+ var f, i, d int
- str = fmt.Sprintf("%.7e ", n.vval);
+ str = fmt.Sprintf("%.7e ", n.vval)
- f = 0;
- for i=1; i<Ndim; i++ {
- d = int(n.dim[i]);
+ 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;
+ 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]);
+ str += " /"
+ for i = 1; i < Ndim; i++ {
+ d = int(n.dim[i])
if d < 0 {
- str = printdim(str, i, -d);
+ str = printdim(str, i, -d)
}
}
}
- return str;
+ return str
}
-func
-(v *Var) String() string {
- var str string;
- str = fmt.Sprintf("%v %v", v.name, v.node);
- 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');
+func readline() bool {
+ s, err := fi.ReadString('\n')
if err != nil {
- return true;
+ return true
}
- line = s;
- linep = 0;
- return false;
+ line = s
+ linep = 0
+ return false
}
-func
-getrune() int {
- var c,n int;
+func getrune() int {
+ var c, n int
if linep >= len(line) {
- return 0;
+ return 0
}
- c,n = utf8.DecodeRuneInString(line[linep:len(line)]);
- linep += n;
+ c, n = utf8.DecodeRuneInString(line[linep:len(line)])
+ linep += n
if c == '\n' {
- c = 0;
+ c = 0
}
- return c;
+ return c
}
-var symmap = make(map[string]*Var); // symbol table
+var symmap = make(map[string]*Var) // symbol table
-func
-lookup(f int) *Var {
- var p float64;
- var w *Var;
+func lookup(f int) *Var {
+ var p float64
+ var w *Var
- v,ok := symmap[sym];
+ v, ok := symmap[sym]
if ok {
- return v;
+ return v
}
if f != 0 {
- return nil;
+ return nil
}
- v = new(Var);
- v.name = sym;
- symmap[sym] = v;
+ v = new(Var)
+ v.name = sym
+ symmap[sym] = v
- p = 1;
+ p = 1
for {
- p = fmul(p, pname());
+ p = fmul(p, pname())
if p == 0 {
- break;
+ break
}
- w = lookup(1);
+ w = lookup(1)
if w != nil {
- v.node = w.node;
- v.node.vval = fmul(v.node.vval, p);
- break;
+ v.node = w.node
+ v.node.vval = fmul(v.node.vval, p)
+ break
}
}
- return v;
+ return v
}
-type
-Prefix struct
-{
- vval float64;
- name string;
+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" },
+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;
+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);
+ 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;
+ sym = sym[j:n]
+ return prefix[i].vval
}
}
@@ -699,82 +676,83 @@
* rip off 's' suffixes
*/
if n > 2 && sym[n-1] == 's' {
- sym = sym[0:n-1];
- return 1;
+ sym = sym[0 : n-1]
+ return 1
}
- return 0;
+ return 0
}
// careful multiplication
// exponents (log) are checked before multiply
-func
-fmul(a, b float64) float64 {
- var l float64;
+func fmul(a, b float64) float64 {
+ var l float64
if b <= 0 {
if b == 0 {
- return 0;
+ return 0
}
- l = math.Log(-b);
- } else
- l = math.Log(b);
+ l = math.Log(-b)
+ } else {
+ l = math.Log(b)
+ }
if a <= 0 {
if a == 0 {
- return 0;
+ return 0
}
- l += math.Log(-a);
- } else
- l += math.Log(a);
+ l += math.Log(-a)
+ } else {
+ l += math.Log(a)
+ }
if l > Maxe {
- Error("overflow in multiply");
- return 1;
+ Error("overflow in multiply")
+ return 1
}
if l < -Maxe {
- Error("underflow in multiply");
- return 0;
+ Error("underflow in multiply")
+ return 0
}
- return a*b;
+ return a * b
}
// careful division
// exponents (log) are checked before divide
-func
-fdiv(a, b float64) float64 {
- var l float64;
+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;
+ Error("division by zero: %v %v", a, b)
+ return 1
}
- l = math.Log(-b);
- } else
- l = math.Log(b);
+ l = math.Log(-b)
+ } else {
+ l = math.Log(b)
+ }
if a <= 0 {
if a == 0 {
- return 0;
+ return 0
}
- l -= math.Log(-a);
- } else
- l -= math.Log(a);
+ l -= math.Log(-a)
+ } else {
+ l -= math.Log(a)
+ }
if l < -Maxe {
- Error("overflow in divide");
- return 1;
+ Error("overflow in divide")
+ return 1
}
if l > Maxe {
- Error("underflow in divide");
- return 0;
+ Error("underflow in divide")
+ return 0
}
- return a/b;
+ return a / b
}
-func
-fadd(a, b float64) float64 {
- return a + b;
+func fadd(a, b float64) float64 {
+ return a + b
}
