v/vlib/v/token/token.v

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// Copyright (c) 2019-2020 Alexander Medvednikov. All rights reserved.
// Use of this source code is governed by an MIT license
// that can be found in the LICENSE file.
module token
pub struct Token {
pub:
kind Kind // the token number/enum; for quick comparisons
lit string // literal representation of the token
line_nr int // the line number in the source where the token occured
// name_idx int // name table index for O(1) lookup
pos int // the position of the token in scanner text
len int // length of the literal
tidx int // the index of the token
}
pub enum Kind {
unknown
eof
name // user
number // 123
string // 'foo'
str_inter // 'name=$user.name'
chartoken // `A`
plus
minus
mul
div
mod
xor // ^
pipe // |
inc // ++
dec // --
and // &&
logical_or
not
bit_not
question
comma
semicolon
colon
arrow // =>
amp
hash
dollar
str_dollar
left_shift
right_shift
not_in // !in
not_is // !is
// at // @
assign // =
decl_assign // :=
plus_assign // +=
minus_assign // -=
div_assign
mult_assign
xor_assign
mod_assign
or_assign
and_assign
right_shift_assign
left_shift_assign
// {} () []
lcbr
rcbr
lpar
rpar
lsbr
rsbr
// == != <= < >= >
eq
ne
gt
lt
ge
le
comment
nl
dot
dotdot
ellipsis
// keywords
keyword_beg
key_as
key_asm
key_assert
key_atomic
key_break
key_const
key_continue
key_defer
key_else
key_embed
key_enum
key_false
key_for
key_fn
key_global
key_go
key_goto
key_if
key_import
key_in
key_interface
key_is
// key_it
key_match
key_module
key_mut
key_shared
key_lock
key_rlock
key_none
key_return
key_select
key_sizeof
key_likely
key_unlikely
key_offsetof
key_struct
key_switch
key_true
key_type
key_typeof
key_orelse
key_union
key_pub
key_static
key_unsafe
keyword_end
_end_
}
const (
assign_tokens = [Kind.assign, .plus_assign, .minus_assign, .mult_assign,
.div_assign, .xor_assign, .mod_assign, .or_assign, .and_assign,
.right_shift_assign, .left_shift_assign]
nr_tokens = int(Kind._end_)
)
// build_keys genereates a map with keywords' string values:
// Keywords['return'] == .key_return
fn build_keys() map[string]Kind {
mut res := map[string]Kind
for t in int(Kind.keyword_beg) + 1 .. int(Kind.keyword_end) {
key := token_str[t]
res[key] = t
}
return res
}
// TODO remove once we have `enum Kind { name('name') if('if') ... }`
fn build_token_str() []string {
mut s := []string{len:(nr_tokens)}
s[Kind.unknown] = 'unknown'
s[Kind.eof] = 'eof'
s[Kind.name] = 'name'
s[Kind.number] = 'number'
s[Kind.string] = 'string'
s[Kind.chartoken] = 'char'
s[Kind.plus] = '+'
s[Kind.minus] = '-'
s[Kind.mul] = '*'
s[Kind.div] = '/'
s[Kind.mod] = '%'
s[Kind.xor] = '^'
s[Kind.bit_not] = '~'
s[Kind.pipe] = '|'
s[Kind.hash] = '#'
s[Kind.amp] = '&'
s[Kind.inc] = '++'
s[Kind.dec] = '--'
s[Kind.and] = '&&'
s[Kind.logical_or] = '||'
s[Kind.not] = '!'
s[Kind.dot] = '.'
s[Kind.dotdot] = '..'
s[Kind.ellipsis] = '...'
s[Kind.comma] = ','
s[Kind.not_in] = '!in'
s[Kind.not_is] = '!is'
// s[Kind.at] = '@'
s[Kind.semicolon] = ';'
s[Kind.colon] = ':'
s[Kind.arrow] = '=>'
s[Kind.assign] = '='
s[Kind.decl_assign] = ':='
s[Kind.plus_assign] = '+='
s[Kind.minus_assign] = '-='
s[Kind.mult_assign] = '*='
s[Kind.div_assign] = '/='
s[Kind.xor_assign] = '^='
s[Kind.mod_assign] = '%='
s[Kind.or_assign] = '|='
s[Kind.and_assign] = '&='
s[Kind.right_shift_assign] = '>>='
s[Kind.left_shift_assign] = '<<='
s[Kind.lcbr] = '{'
s[Kind.rcbr] = '}'
s[Kind.lpar] = '('
s[Kind.rpar] = ')'
s[Kind.lsbr] = '['
s[Kind.rsbr] = ']'
s[Kind.eq] = '=='
s[Kind.ne] = '!='
s[Kind.gt] = '>'
s[Kind.lt] = '<'
s[Kind.ge] = '>='
s[Kind.le] = '<='
s[Kind.question] = '?'
s[Kind.left_shift] = '<<'
s[Kind.right_shift] = '>>'
s[Kind.comment] = '// comment'
s[Kind.nl] = 'NLL'
s[Kind.dollar] = '$'
s[Kind.str_dollar] = '$2'
s[Kind.key_assert] = 'assert'
s[Kind.key_struct] = 'struct'
s[Kind.key_if] = 'if'
// s[Kind.key_it] = 'it'
s[Kind.key_else] = 'else'
s[Kind.key_asm] = 'asm'
s[Kind.key_return] = 'return'
s[Kind.key_module] = 'module'
s[Kind.key_sizeof] = 'sizeof'
s[Kind.key_likely] = '_likely_'
s[Kind.key_unlikely] = '_unlikely_'
s[Kind.key_go] = 'go'
s[Kind.key_goto] = 'goto'
s[Kind.key_const] = 'const'
s[Kind.key_mut] = 'mut'
s[Kind.key_shared] = 'shared'
s[Kind.key_lock] = 'lock'
s[Kind.key_rlock] = 'rlock'
s[Kind.key_type] = 'type'
s[Kind.key_for] = 'for'
s[Kind.key_switch] = 'switch'
s[Kind.key_fn] = 'fn'
s[Kind.key_true] = 'true'
s[Kind.key_false] = 'false'
s[Kind.key_continue] = 'continue'
s[Kind.key_break] = 'break'
s[Kind.key_import] = 'import'
s[Kind.key_embed] = 'embed'
s[Kind.key_unsafe] = 'unsafe'
s[Kind.key_typeof] = 'typeof'
s[Kind.key_enum] = 'enum'
s[Kind.key_interface] = 'interface'
s[Kind.key_pub] = 'pub'
s[Kind.key_in] = 'in'
s[Kind.key_atomic] = 'atomic'
s[Kind.key_orelse] = 'or'
s[Kind.key_global] = '__global'
s[Kind.key_union] = 'union'
s[Kind.key_static] = 'static'
s[Kind.key_as] = 'as'
s[Kind.key_defer] = 'defer'
s[Kind.key_match] = 'match'
s[Kind.key_select] = 'select'
s[Kind.key_none] = 'none'
s[Kind.key_offsetof] = '__offsetof'
s[Kind.key_is] = 'is'
return s
}
const (
token_str = build_token_str()
keywords = build_keys()
)
pub fn key_to_token(key string) Kind {
a := Kind(keywords[key])
return a
}
pub fn is_key(key string) bool {
return int(key_to_token(key)) > 0
}
pub fn is_decl(t Kind) bool {
return t in [.key_enum, .key_interface, .key_fn, .key_struct, .key_type, .key_const, .key_pub, .eof]
}
pub fn (t Kind) is_assign() bool {
return t in assign_tokens
}
fn (t []Kind) contains(val Kind) bool {
for tt in t {
if tt == val {
return true
}
}
return false
}
pub fn (t Kind) str() string {
return token_str[int(t)]
}
pub fn (t Token) str() string {
return '$t.kind.str() "$t.lit"'
}
// Representation of highest and lowest precedence
/*
pub const (
lowest_prec = 0
highest_prec = 8
)
*/
pub enum Precedence {
lowest
cond // OR or AND
in_as
assign // =
eq // == or !=
// less_greater // > or <
sum // + - | ^
product // * / << >> &
// mod // %
prefix // -X or !X
postfix // ++ or --
call // func(X) or foo.method(X)
index // array[index], map[key]
}
pub fn build_precedences() []Precedence {
mut p := []Precedence{len:int(Kind._end_), cap:int(Kind._end_)}
p[Kind.lsbr] = .index
p[Kind.dot] = .call
// `++` | `--`
p[Kind.inc] = .postfix
p[Kind.dec] = .postfix
// `*` | `/` | `%` | `<<` | `>>` | `&`
p[Kind.mul] = .product
p[Kind.div] = .product
p[Kind.mod] = .product
p[Kind.left_shift] = .product
p[Kind.right_shift] = .product
p[Kind.amp] = .product
// `+` | `-` | `|` | `^`
p[Kind.plus] = .sum
p[Kind.minus] = .sum
p[Kind.pipe] = .sum
p[Kind.xor] = .sum
// `==` | `!=` | `<` | `<=` | `>` | `>=`
p[Kind.eq] = .eq
p[Kind.ne] = .eq
p[Kind.lt] = .eq
p[Kind.le] = .eq
p[Kind.gt] = .eq
p[Kind.ge] = .eq
// `=` | `+=` | ...
p[Kind.assign] = .assign
p[Kind.plus_assign] = .assign
p[Kind.minus_assign] = .assign
p[Kind.div_assign] = .assign
p[Kind.mod_assign] = .assign
p[Kind.or_assign] = .assign
p[Kind.and_assign] = .assign
// <<= | *= | ...
p[Kind.left_shift_assign] = .assign
p[Kind.right_shift_assign] = .assign
p[Kind.mult_assign] = .assign
p[Kind.xor_assign] = .assign
p[Kind.key_in] = .in_as
p[Kind.not_in] = .in_as
p[Kind.key_as] = .in_as
p[Kind.key_is] = .in_as
p[Kind.not_is] = .in_as
p[Kind.logical_or] = .cond
p[Kind.and] = .cond
return p
}
const (
precedences = build_precedences()
)
// precedence returns a tokens precedence if defined, otherwise lowest_prec
pub fn (tok Token) precedence() int {
return int(precedences[tok.kind])
}
// is_scalar returns true if the token is a scalar
pub fn (tok Token) is_scalar() bool {
return tok.kind in [.number, .string]
}
// is_unary returns true if the token can be in a unary expression
pub fn (tok Token) is_unary() bool {
return tok.kind in [
// `+` | `-` | `!` | `~` | `*` | `&`
.plus, .minus, .not, .bit_not, .mul, .amp]
}
pub fn (tok Kind) is_relational() bool {
return tok in [
// `<` | `<=` | `>` | `>=`
.lt, .le, .gt, .ge, .eq, .ne]
}
pub fn (k Kind) is_start_of_type() bool {
return k in [.name, .lpar, .amp, .lsbr, .question]
}
pub fn (kind Kind) is_infix() bool {
return kind in [.plus, .minus, .mod, .mul, .div, .eq, .ne, .gt, .lt, .key_in,
//
.key_as, .ge, .le, .logical_or, .xor, .not_in, .key_is, .not_is,
//
.and, .dot, .pipe, .amp, .left_shift, .right_shift]
}