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v/vlib/v/token/token.v
2019-12-27 10:00:44 +01:00

373 lines
7.5 KiB
V

// Copyright (c) 2019 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
/*
struct Token {
tok TokenKind // 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
}
*/
pub enum Token {
eof
name // user
number // 123
str // '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
righ_shift
// at // @
assign // =
decl_assign // :=
plus_assign // +=
minus_assign // -=
div_assign
mult_assign
xor_assign
mod_assign
or_assign
and_assign
righ_shift_assign
left_shift_assign
// {} () []
lcbr
rcbr
lpar
rpar
lsbr
rsbr
// == != <= < >= >
eq
ne
gt
lt
ge
le
// comments
line_comment
mline_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_import_const
key_in
key_interface
// key_it
key_match
key_module
key_mut
key_none
key_return
key_select
key_sizeof
key_offsetof
key_struct
key_switch
key_true
key_type
// typeof
key_orelse
key_union
key_pub
key_static
key_unsafe
keyword_end
}
const (
assign_tokens = [Token.assign, .plus_assign, .minus_assign, .mult_assign,
.div_assign, .xor_assign, .mod_assign, .or_assign, .and_assign,
.righ_shift_assign, .left_shift_assign]
nr_tokens = 141
)
// build_keys genereates a map with keywords' string values:
// Keywords['return'] == .key_return
fn build_keys() map[string]int {
mut res := map[string]int
for t := int(Token.keyword_beg) + 1; t < int(Token.keyword_end); t++ {
key := token_str[t]
res[key] = t
}
return res
}
// TODO remove once we have `enum Token { name('name') if('if') ... }`
fn build_token_str() []string {
mut s := [''].repeat(nr_tokens)
s[Token.keyword_beg] = ''
s[Token.keyword_end] = ''
s[Token.eof] = 'eof'
s[Token.name] = 'name'
s[Token.number] = 'number'
s[Token.str] = 'STR'
s[Token.chartoken] = 'char'
s[Token.plus] = '+'
s[Token.minus] = '-'
s[Token.mul] = '*'
s[Token.div] = '/'
s[Token.mod] = '%'
s[Token.xor] = '^'
s[Token.bit_not] = '~'
s[Token.pipe] = '|'
s[Token.hash] = '#'
s[Token.amp] = '&'
s[Token.inc] = '++'
s[Token.dec] = '--'
s[Token.and] = '&&'
s[Token.logical_or] = '||'
s[Token.not] = '!'
s[Token.dot] = '.'
s[Token.dotdot] = '..'
s[Token.ellipsis] = '...'
s[Token.comma] = ','
// s[Token.at] = '@'
s[Token.semicolon] = ';'
s[Token.colon] = ':'
s[Token.arrow] = '=>'
s[Token.assign] = '='
s[Token.decl_assign] = ':='
s[Token.plus_assign] = '+='
s[Token.minus_assign] = '-='
s[Token.mult_assign] = '*='
s[Token.div_assign] = '/='
s[Token.xor_assign] = '^='
s[Token.mod_assign] = '%='
s[Token.or_assign] = '|='
s[Token.and_assign] = '&='
s[Token.righ_shift_assign] = '>>='
s[Token.left_shift_assign] = '<<='
s[Token.lcbr] = '{'
s[Token.rcbr] = '}'
s[Token.lpar] = '('
s[Token.rpar] = ')'
s[Token.lsbr] = '['
s[Token.rsbr] = ']'
s[Token.eq] = '=='
s[Token.ne] = '!='
s[Token.gt] = '>'
s[Token.lt] = '<'
s[Token.ge] = '>='
s[Token.le] = '<='
s[Token.question] = '?'
s[Token.left_shift] = '<<'
s[Token.righ_shift] = '>>'
s[Token.line_comment] = '// line comment'
s[Token.mline_comment] = '/* mline comment */'
s[Token.nl] = 'NLL'
s[Token.dollar] = '$'
s[Token.str_dollar] = '$2'
s[Token.key_assert] = 'assert'
s[Token.key_struct] = 'struct'
s[Token.key_if] = 'if'
// s[Token.key_it] = 'it'
s[Token.key_else] = 'else'
s[Token.key_asm] = 'asm'
s[Token.key_return] = 'return'
s[Token.key_module] = 'module'
s[Token.key_sizeof] = 'sizeof'
s[Token.key_go] = 'go'
s[Token.key_goto] = 'goto'
s[Token.key_const] = 'const'
s[Token.key_mut] = 'mut'
s[Token.key_type] = 'type'
s[Token.key_for] = 'for'
s[Token.key_switch] = 'switch'
s[Token.key_fn] = 'fn'
s[Token.key_true] = 'true'
s[Token.key_false] = 'false'
s[Token.key_continue] = 'continue'
s[Token.key_break] = 'break'
s[Token.key_import] = 'import'
s[Token.key_embed] = 'embed'
s[Token.key_unsafe] = 'unsafe'
// Tokens[key_typeof] = 'typeof'
s[Token.key_enum] = 'enum'
s[Token.key_interface] = 'interface'
s[Token.key_pub] = 'pub'
s[Token.key_import_const] = 'import_const'
s[Token.key_in] = 'in'
s[Token.key_atomic] = 'atomic'
s[Token.key_orelse] = 'or'
s[Token.key_global] = '__global'
s[Token.key_union] = 'union'
s[Token.key_static] = 'static'
s[Token.key_as] = 'as'
s[Token.key_defer] = 'defer'
s[Token.key_match] = 'match'
s[Token.key_select] = 'select'
s[Token.key_none] = 'none'
s[Token.key_offsetof] = '__offsetof'
return s
}
const (
token_str = build_token_str()
keywords = build_keys()
)
pub fn key_to_token(key string) Token {
a := Token(keywords[key])
return a
}
pub fn is_key(key string) bool {
return int(key_to_token(key)) > 0
}
pub fn is_decl(t Token) bool {
return t in [.key_enum,
.key_interface, .key_fn, .key_struct, .key_type, .key_const, .key_import_const,
.key_pub, .eof]
}
fn (t Token) is_assign() bool {
return t in assign_tokens
}
fn (t []Token) contains(val Token) bool {
for tt in t {
if tt == val {
return true
}
}
return false
}
pub fn (t Token) str() string {
lit := 't.lit'
if t == .number {
return 'number'
}
if t == .chartoken {
return '`lit`'
}
if t == .str {
return "'lit'"
}
if t < .plus {
return lit // string, number etc
}
return token_str[int(t)]
}
// Representation of highest and lowest precedence
const (
lowest_prec = 0
highest_prec = 7
)
// Precedence returns a tokens precedence if defined, otherwise lowest_prec
pub fn (tok Token) precedence() int {
match tok {
// `*` | `/` | `%` | `<<` | `>>` | `&`
.mul, .div, .left_shift, .righ_shift, .amp { return 7 }
// `+` | `-` | `|` | `^`
.plus, .minus, .pipe, .xor { return 6 }
// `==` | `!=` | `<` | `<=` | `>` | `>=` | +=
.eq, .ne, .lt, .le, .gt, .ge, .plus_assign { return 5 }
// `&&`
.and { return 4 }
// `||`
.logical_or { return 3 }
else { return lowest_prec }
}
}
// is_scalar returns true if the token is a scalar
pub fn (tok Token) is_scalar() bool {
return tok in [.number, .str]
}
// is_unary returns true if the token can be in a unary expression
pub fn (tok Token) is_unary() bool {
return tok in [
// `+` | `-` | `!` | `~` | `*` | `&`
.plus, .minus, .not, .bit_not, .mul, .amp
]
}
// NOTE: do we need this for all tokens (is_left_assoc / is_right_assoc),
// or only ones with the same precedence?
// is_left_assoc returns true if the token is left associative
pub fn (tok Token) is_left_assoc() bool {
return tok in [
// .number,
// `*` | `/` | `%`
.mul, .div, .mod,
// `^` | `||` | `&`
.xor, .logical_or, .and,
// `,`
.comma
]
}
// is_right_assoc returns true if the token is right associative
pub fn (tok Token) is_right_assoc() bool {
return tok in [
// `+` | `-` | `!` | `++` | `--`
.plus, .minus, .not, .inc, .dec,
// `=` | `+=` | `-=` | `*=` | `/=`
.assign, .plus_assign, .minus_assign, .mult_assign, .div_assign,
// `%=` | `>>=` | `<<=`
.mod_assign, .righ_shift_assign, .left_shift_assign,
// `&=` | `^=` | `|=`
.and_assign, .xor_assign, .or_assign
]
}