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simplify and improve pratt

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This commit is contained in:
Alexander Medvednikov
2020-01-06 16:13:12 +01:00
committed by GitHub
parent 025efcb731
commit b815878d60
18 changed files with 861 additions and 518 deletions
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66
vlib/v/token/token.v
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@@ -267,8 +267,8 @@ pub fn is_decl(t Kind) bool {
return t in [.key_enum, .key_interface, .key_fn, .key_struct, .key_type, .key_const, .key_import_const, .key_pub, .eof]
}
pub fn (t Token) is_assign() bool {
return t.kind in assign_tokens
pub fn (t Kind) is_assign() bool {
return t in assign_tokens
}
fn (t []Kind) contains(val Kind) bool {
@@ -308,7 +308,54 @@ pub const (
lowest_prec = 0
highest_prec = 8
)
// Precedence returns a tokens precedence if defined, otherwise lowest_prec
pub enum Precedence {
lowest
cond // OR or AND
assign // =
eq // == or !=
less_greater // > or <
sum // + or -
product // * or /
mod // %
prefix // -X or !X
call // func(X) or foo.method(X)
index // array[index], map[key]
}
pub fn build_precedences() []Precedence {
mut p := []Precedence
p = make(100, 100, sizeof(Precedence))
p[Kind.assign] = .assign
p[Kind.eq] = .eq
p[Kind.ne] = .eq
p[Kind.lt] = .less_greater
p[Kind.gt] = .less_greater
p[Kind.le] = .less_greater
p[Kind.ge] = .less_greater
p[Kind.plus] = .sum
p[Kind.plus_assign] = .sum
p[Kind.minus] = .sum
p[Kind.minus_assign] = .sum
p[Kind.div] = .product
p[Kind.div_assign] = .product
p[Kind.mul] = .product
p[Kind.mult_assign] = .product
p[Kind.mod] = .mod
p[Kind.and] = .cond
p[Kind.logical_or] = .cond
p[Kind.lpar] = .call
p[Kind.dot] = .call
p[Kind.lsbr] = .index
return p
}
const (
precedences = build_precedences()
// int(Kind.assign): Precedence.assign
// }
)
// precedence returns a tokens precedence if defined, otherwise lowest_prec
pub fn (tok Token) precedence() int {
match tok.kind {
.dot {
@@ -316,6 +363,7 @@ pub fn (tok Token) precedence() int {
}
// `++` | `--`
.inc, .dec {
// return 0
return 7
}
// `*` | `/` | `%` | `<<` | `>>` | `&`
@@ -335,7 +383,7 @@ pub fn (tok Token) precedence() int {
return 3
}
// `||`
.logical_or {
.logical_or, .assign, .plus_assign, .minus_assign, .div_assign, .mult_assign {
return 2
}
// /.plus_assign {
@@ -366,7 +414,7 @@ pub fn (tok Token) is_left_assoc() bool {
return tok.kind in [
// `.`
.dot,
// `+` | `-`
// `+` | `-`
.plus, .minus, // additive
// .number,
// `++` | `--`
@@ -396,8 +444,12 @@ pub fn (tok Token) is_right_assoc() bool {
.and_assign, .xor_assign, .or_assign]
}
pub fn (tok Token) is_relational() bool {
return tok.kind in [
pub fn (tok Kind) is_relational() bool {
return tok in [
// `<` | `<=` | `>` | `>=`
.lt, .le, .gt, .ge, .eq, .ne]
}
pub fn (kind Kind) is_infix() bool {
return kind in [.plus, .minus, .mod, .mul, .div, .eq, .ne, .gt, .lt, .ge, .le, .logical_or, .and, .dot]
}