Lexer: move numbers to a separate file

This commit is contained in:
Aleksey Kladov 2017-12-30 15:56:52 +03:00
parent 2d5217dbb7
commit 3e91e8b77d
4 changed files with 73 additions and 63 deletions

View File

@ -7,6 +7,9 @@ use self::ptr::Ptr;
mod classes;
use self::classes::*;
mod numbers;
use self::numbers::scan_number;
pub fn next_token(text: &str) -> Token {
assert!(!text.is_empty());
let mut ptr = Ptr::new(text);
@ -50,69 +53,6 @@ fn scan_ident(c: char, ptr: &mut Ptr) -> SyntaxKind {
IDENT
}
fn scan_number(c: char, ptr: &mut Ptr) -> SyntaxKind {
if c == '0' {
match ptr.next().unwrap_or('\0') {
'b' | 'o' => {
ptr.bump();
scan_digits(ptr, false);
}
'x' => {
ptr.bump();
scan_digits(ptr, true);
}
'0'...'9' | '_' | '.' | 'e' | 'E' => {
scan_digits(ptr, true);
}
_ => return INT_NUMBER,
}
} else {
scan_digits(ptr, false);
}
// might be a float, but don't be greedy if this is actually an
// integer literal followed by field/method access or a range pattern
// (`0..2` and `12.foo()`)
if ptr.next_is('.') && !(ptr.nnext_is('.') || ptr.nnext_is_p(is_ident_start)) {
// might have stuff after the ., and if it does, it needs to start
// with a number
ptr.bump();
scan_digits(ptr, false);
scan_float_exponent(ptr);
return FLOAT_NUMBER;
}
// it might be a float if it has an exponent
if ptr.next_is('e') || ptr.next_is('E') {
scan_float_exponent(ptr);
return FLOAT_NUMBER;
}
INT_NUMBER
}
fn scan_digits(ptr: &mut Ptr, allow_hex: bool) {
while let Some(c) = ptr.next() {
match c {
'_' | '0'...'9' => {
ptr.bump();
}
'a'...'f' | 'A' ... 'F' if allow_hex => {
ptr.bump();
}
_ => return
}
}
}
fn scan_float_exponent(ptr: &mut Ptr) {
if ptr.next_is('e') || ptr.next_is('E') {
ptr.bump();
if ptr.next_is('-') || ptr.next_is('+') {
ptr.bump();
}
scan_digits(ptr, false);
}
}
fn string_literal_start(c: char, c1: Option<char>, c2: Option<char>) -> bool {
match (c, c1, c2) {
('r', Some('"'), _) |

68
src/lexer/numbers.rs Normal file
View File

@ -0,0 +1,68 @@
use lexer::ptr::Ptr;
use lexer::classes::*;
use {SyntaxKind};
use syntax_kinds::*;
pub(crate) fn scan_number(c: char, ptr: &mut Ptr) -> SyntaxKind {
if c == '0' {
match ptr.next().unwrap_or('\0') {
'b' | 'o' => {
ptr.bump();
scan_digits(ptr, false);
}
'x' => {
ptr.bump();
scan_digits(ptr, true);
}
'0'...'9' | '_' | '.' | 'e' | 'E' => {
scan_digits(ptr, true);
}
_ => return INT_NUMBER,
}
} else {
scan_digits(ptr, false);
}
// might be a float, but don't be greedy if this is actually an
// integer literal followed by field/method access or a range pattern
// (`0..2` and `12.foo()`)
if ptr.next_is('.') && !(ptr.nnext_is('.') || ptr.nnext_is_p(is_ident_start)) {
// might have stuff after the ., and if it does, it needs to start
// with a number
ptr.bump();
scan_digits(ptr, false);
scan_float_exponent(ptr);
return FLOAT_NUMBER;
}
// it might be a float if it has an exponent
if ptr.next_is('e') || ptr.next_is('E') {
scan_float_exponent(ptr);
return FLOAT_NUMBER;
}
INT_NUMBER
}
fn scan_digits(ptr: &mut Ptr, allow_hex: bool) {
while let Some(c) = ptr.next() {
match c {
'_' | '0'...'9' => {
ptr.bump();
}
'a'...'f' | 'A' ... 'F' if allow_hex => {
ptr.bump();
}
_ => return
}
}
}
fn scan_float_exponent(ptr: &mut Ptr) {
if ptr.next_is('e') || ptr.next_is('E') {
ptr.bump();
if ptr.next_is('-') || ptr.next_is('+') {
ptr.bump();
}
scan_digits(ptr, false);
}
}

View File

@ -5,3 +5,4 @@
0e+1
0.e+1
0.0E-2
0___0.10000____0000e+111__

View File

@ -60,3 +60,4 @@ INT_NUMBER 1 "1"
WHITESPACE 1 "\n"
FLOAT_NUMBER 6 "0.0E-2"
WHITESPACE 1 "\n"
FLOAT_NUMBER 26 "0___0.10000____0000e+111__"