ref: 8bc429fb93070938b8bc5d459da4f2664c00abae
dir: /mparse/tok.myr/
use std
use "types.use"
use "tokdefs.use"
use "util.use"
pkg parse =
type tokstream = struct
next : std.option(tok)
rest : byte[:]
data : byte[:]
loc : srcloc
;;
const tokinit : (path : byte[:] -> tokstream#)
const tokinitf : (path : std.fd -> tokstream#)
const tokclose : (ts : tokstream# -> void)
const toknext : (ts : tokstream# -> tok)
const tokpeek : (ts : tokstream# -> tok)
;;
const Eof = std.Badchar
const tokinit = {path
match std.slurp(path)
| `std.Ok data: -> std.mk([.next=`std.None, .rest=data, .data=data])
| `std.Fail e: std.fatal("could not read file {}: {}\n", path, e)
;;
}
const tokinitf = {fd
match std.fslurp(fd)
| `std.Ok data: -> std.mk([.next=`std.None, .rest=data, .data=data])
| `std.Fail e: std.fatal("could not read file {}: {}\n", fd, e)
;;
}
const tokclose = {ts
std.slfree(ts.data)
std.free(ts)
}
const toknext = {ts
var t
match ts.next
| `std.Some tok:
ts.next = `std.None
std.put("tok: {}\n", tok)
-> tok
| `std.None:
t = tokread(ts)
std.put("t: {}\n", t)
-> t
;;
}
const tokpeek = {ts
var tok
match ts.next
| `std.Some t:
-> t
| `std.None:
tok = tokread(ts)
ts.next = `std.Some tok
-> tok
;;
}
const tokread : (ts : tokstream# -> tok) = {ts
var c
skipspace(ts)
c = peekc(ts)
if ts.rest.len == 0
-> `Teof
elif c == '\n'
takec(ts)
ts.loc.line++
ts.loc.col = 1
-> `Tendln
elif c == '\''
-> chrlit(ts)
elif c == '"'
-> strlit(ts)
elif c == '@'
-> typaram(ts)
elif isident(c)
-> kwident(ts)
elif std.isdigit(c)
-> numlit(ts)
else
-> oper(ts)
;;
}
const skipspace = {ts
var ignorenl
ignorenl = false
while true
match peekc(ts)
| '\n':
if ignorenl
takec(ts)
ts.loc.line++
ts.loc.col = 1
else
break
;;
| '\\':
ignorenl = true
takec(ts)
| '/':
match npeekc(ts, 1)
| '/': skipto(ts, '\n')
| '*': skipcomment(ts)
| _: break
;;
| c:
if std.isspace(c)
takec(ts)
else
break
;;
;;
;;
}
const skipcomment = {ts
var depth, startln
depth = 0
startln = ts.loc.line
while true
match takec(ts)
| '/':
if matchc(ts, '*')
depth++
;;
| '*':
if matchc(ts, '/')
depth--
;;
| '\n':
ts.loc.line++
ts.loc.col = 1
| Eof:
err(ts.loc, "file ended in comment starting on line {}\n", startln)
| _:
;;
if depth == 0
break
;;
;;
}
const chrlit = {ts
var c, close
takec(ts)
c = takec(ts)
if c == '\\'
c = unescape(ts)
;;
close = takec(ts)
if close != '\''
err(ts.loc, "expected closing ' in character literal, got {}\n", close)
;;
-> `Tchrlit c
}
const strlit = {ts
var sb
takec(ts)
sb = std.mksb()
while true
match takec(ts)
| Eof:
err(ts.loc, "unexpected EOF within string literal\n")
| '\n':
err(ts.loc, "unexpected \\n within string literal\n")
| '"':
break
| '\\':
std.sbputc(sb, unescape(ts))
| c:
std.sbputc(sb, c)
;;
;;
-> `Tstrlit std.sbfin(sb)
}
const unescape = {ts
var c, c1, c2
c = takec(ts)
/* we've already seen the '\' */
match c
| 'n': -> '\n'
| 'r': -> '\r'
| 't': -> '\t'
| 'b': -> '\b'
| '"': -> '\"'
| '\'': -> '\''
| 'v': -> '\v'
| '\\': -> '\\'
| '0': -> '\0'
| 'u': -> utfesc(ts);
| 'x':
c1 = takec(ts)
if !std.isxdigit(c1)
err(ts.loc, "expected hex digit, got {}\n", c1)
;;
c2 = takec(ts)
if !std.isxdigit(c2)
err(ts.loc, "expected hex digit, got {}\n", c2)
;;
-> 16*std.charval(c1, 16) + std.charval(c2, 16)
c2 = takec(ts)
| esc:
err(ts.loc, "unknown escape code \\{}\n", esc)
;;
}
const utfesc = {ts
var c, v
if takec(ts) != '{'
err(ts.loc, "\\u escape sequence without initial '{'\n")
;;
v = 0
c = std.Badchar
while true
c = takec(ts)
if std.isxdigit(c)
v *= 16
v += std.charval(c, 16)
else
break
;;
if v > 0x10FFFF
err(ts.loc, "invalid codepoint in \\u escape sequence\n")
;;
;;
if c != '}'
err(ts.loc, "\\u escape sequence without closing '{'\n")
;;
-> v
}
const typaram = {ts
takec(ts)
match kwident(ts)
| `Tident id:
-> `Ttyparam id
| kw:
err(ts.loc, "'{}' used as type parameter\n", kw)
;;
}
const numlit = {ts
var t
if matchc(ts, '0')
if matchc(ts, 'x')
t = number(ts, 16)
elif matchc(ts, 'b')
t = number(ts, 2)
elif matchc('o')
t = number(ts, 8)
else
t = number(ts, 10)
;;
else
t = number(ts, 10)
;;
-> t
}
/*
only deals with the body of the number. if we reach
this code, then it's guaranteed that we already have
a numerical value.
*/
const number = {ts, base
}
const kwident = {ts
match identstr(ts)
| "$": -> `Tidxlen
| "_": -> `Tgap
| "$noret": -> `Tattr `Attrnoret
| "break": -> `Tbreak
| "castto": -> `Tcast
| "const": -> `Tconst
| "continue": -> `Tcontinue
| "elif": -> `Telif
| "else": -> `Telse
| "extern": -> `Tattr `Attrextern
| "false": -> `Tboollit false
| "for": -> `Tfor
| "generic": -> `Tgeneric
| "goto": -> `Tgoto
| "if": -> `Tif
| "impl": -> `Timpl
| "in": -> `Tin
| "match": -> `Tmatch
| "pkg": -> `Tpkg
| "pkglocal": -> `Tattr `Attrpkglocal
| "sizeof": -> `Tsizeof
| "struct": -> `Tstruct
| "trait": -> `Ttrait
| "true": -> `Tboollit true
| "type": -> `Ttype
| "union": -> `Tunion
| "use": -> `Tuse
| "var": -> `Tvar
| "void": -> `Tvoidlit
| "while": -> `Twhile
| ident: -> `Tident ident
;;
}
const oper = {ts
var t, chr
chr = takec(ts)
std.put("c = '{}'\n", chr)
t = `Tobrace
match chr
| '{': t = `Tobrace
| '}': t = `Tcbrace
| '(': t = `Toparen
| ')': t = `Tcparen
| '[': t = `Tosqbrac
| ']': t = `Tcsqbrac
| ',': t = `Tcomma
| '`': t = `Ttick
| '#': t = `Tderef
| '~': t = `Tbnot
| ':':
if matchc(ts, ':')
t = `Twith
else
t = `Tcolon;
;;
| ';':
if matchc(ts, ';')
t = `Tendblk;
else
t = `Tendln;
;;
| '.':
if npeekc(ts, 1) == '.' && npeekc(ts, 2) == '.'
takec(ts)
takec(ts)
t = `Tellipsis;
else
t = `Tdot;
;;
| '+':
if matchc(ts, '=')
t = `Taddeq;
elif matchc(ts, '+')
t = `Tinc;
else
t = `Tplus;
;;
| '-':
if matchc(ts, '=')
t = `Tsubeq;
elif matchc(ts, '-')
t = `Tdec;
elif matchc(ts, '>')
t = `Tret;
else
t = `Tminus;
;;
| '*':
if matchc(ts, '=')
t = `Tmuleq;
else
t = `Tmul;
;;
| '/':
if matchc(ts, '=')
t = `Tdiveq;
else
t = `Tdiv;
;;
| '%':
if matchc(ts, '=')
t = `Tmodeq;
else
t = `Tmod;
;;
| '=':
if matchc(ts, '=')
t = `Teq;
else
t = `Tasn;
;;
| '|':
if matchc(ts, '=')
t = `Tboreq;
elif matchc(ts, '|')
t = `Tlor;
else
t = `Tbor;
;;
| '&':
if matchc(ts, '=')
t = `Tbandeq;
elif matchc(ts, '&')
t = `Tland;
else
t = `Tband;
;;
| '^':
if matchc(ts, '=')
t = `Tbxoreq;
else
t = `Tbxor;
;;
| '<':
if matchc(ts, '=')
t = `Tle;
elif matchc(ts, '<')
if matchc(ts, '=')
t = `Tbsleq;
else
t = `Tbsl;
;;
else
t = `Tlt;
;;
| '>':
if matchc(ts, '=')
t = `Tge;
elif matchc(ts, '>')
if matchc(ts, '=')
t = `Tbsreq;
else
t = `Tbsr;
;;
else
t = `Tgt;
;;
| '!':
if matchc(ts, '=')
t = `Tne;
else
t = `Tlnot;
;;
| c:
t = `Terror;
err(ts.loc, "junk character {}", c);
;;
-> t
}
const identstr = {ts
var i, str
/* ASCII */
if ts.rest.len == 0 || std.isdigit(ts.rest[0] castto(char))
-> ""
;;
for i = 0; i < ts.rest.len; i++
if !isident(ts.rest[i] castto(char))
break
;;
;;
str = ts.rest[:i]
ts.rest = ts.rest[i:]
-> std.sldup(str)
}
const isident = {c
-> c & 0x80 == 0 && \
(c >= 'a' && c <= 'z' || \
c >= 'A' && c <= 'Z' || \
c >= '0' && c <= '9' || \
c == '_' || c == '$')
}
const peekc = {ts
-> std.decode(ts.rest)
}
const npeekc = {ts, n
var c, s
s = ts.rest
for var i = 0; i < n; i++
(c, s) = std.strstep(s)
;;
-> std.decode(s)
}
const takec = {ts
var c, s
(c, s) = std.strstep(ts.rest)
ts.rest = s
-> c
}
const skipto = {ts, chr
var c, s
s = ts.rest
while true
(c, s) = std.strstep(s)
if s.len == 0 || c == chr
break
;;
;;
}
const matchc = {ts, chr
var c, s
(c, s) = std.strstep(ts.rest)
if c == chr
ts.rest = s
-> true
else
-> false
;;
}