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Escaping now works in the DataTree tokenizer.

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Also byte offsets of the tokens in the text are now stored in
the tokens, for eventual use in parse error messages.
This commit is contained in:
Nathan Vegdahl 2016-03-06 14:10:17 -08:00
parent d769ccecee
commit 62389d42ae
1 changed files with 85 additions and 41 deletions
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126
src/datatree.rs
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@ -51,27 +51,34 @@ fn parse_node(ti: &mut TokenIter) -> Option<Node> {
fn token_iter<'a>(text: &'a str) -> TokenIter<'a> { fn token_iter<'a>(text: &'a str) -> TokenIter<'a> {
TokenIter { TokenIter {
text: text, text: text,
bytes_consumed: 0,
after_open_leaf: false, after_open_leaf: false,
} }
} }
/// /////////////////////////////////////////////////////////////
// ================================================================
/// Tokens contain their starting byte offset in the original source
/// text. Some variants also contain a string slice of the relevant
/// text.
#[derive(Debug, PartialEq, Eq)] #[derive(Debug, PartialEq, Eq)]
enum Token<'a> { enum Token<'a> {
TypeName(&'a str), TypeName((usize, &'a str)),
Ident(&'a str), Ident((usize, &'a str)),
OpenInner, OpenInner(usize),
CloseInner, CloseInner(usize),
OpenLeaf, OpenLeaf(usize),
CloseLeaf, CloseLeaf(usize),
LeafContents(&'a str), LeafContents((usize, &'a str)),
Unknown, Unknown(usize),
} }
struct TokenIter<'a> { struct TokenIter<'a> {
text: &'a str, text: &'a str,
bytes_consumed: usize,
after_open_leaf: bool, after_open_leaf: bool,
} }
@ -122,7 +129,7 @@ impl<'a> Iterator for TokenIter<'a> {
iter.next(); iter.next();
let i1 = i; let i1 = i;
let i2 = { let i2 = {
let mut i2 = 0; let mut i2 = i1;
while let Some(&(i, c)) = iter.peek() { while let Some(&(i, c)) = iter.peek() {
if is_ident_char(c) { if is_ident_char(c) {
iter.next(); iter.next();
@ -133,78 +140,85 @@ impl<'a> Iterator for TokenIter<'a> {
} }
i2 i2
}; };
token = Some(Token::TypeName(&self.text[i1..i2])); token = Some(Token::TypeName((self.bytes_consumed + i1, &self.text[i1..i2])));
} }
// Ident // Ident
// TODO: handle escaping
else if c == '$' { else if c == '$' {
iter.next(); iter.next();
let i1 = i; let i1 = i;
let i2 = { let i2 = {
let mut i2 = 0; let mut i2 = i1;
let mut escaped = false;
while let Some(&(i, c)) = iter.peek() { while let Some(&(i, c)) = iter.peek() {
if is_ident_char(c) { if escaped {
iter.next(); escaped = false;
} else { } else if c == '\\' {
escaped = true;
} else if !is_ident_char(c) {
i2 = i; i2 = i;
break; break;
} }
iter.next();
} }
i2 i2
}; };
token = Some(Token::Ident(&self.text[i1..i2])); token = Some(Token::Ident((self.bytes_consumed + i1, &self.text[i1..i2])));
} }
// Structural characters // Structural characters
else if is_reserved_char(c) { else if is_reserved_char(c) {
iter.next(); iter.next();
match c { match c {
'{' => { '{' => {
token = Some(Token::OpenInner); token = Some(Token::OpenInner(self.bytes_consumed + i));
} }
'}' => { '}' => {
token = Some(Token::CloseInner); token = Some(Token::CloseInner(self.bytes_consumed + i));
} }
'[' => { '[' => {
self.after_open_leaf = true; self.after_open_leaf = true;
token = Some(Token::OpenLeaf); token = Some(Token::OpenLeaf(self.bytes_consumed + i));
} }
']' => { ']' => {
token = Some(Token::CloseLeaf); token = Some(Token::CloseLeaf(self.bytes_consumed + i));
} }
_ => { _ => {
token = Some(Token::Unknown); token = Some(Token::Unknown(self.bytes_consumed + i));
} }
} }
} }
} }
} }
// Leaf contents // Leaf contents
// TODO: handle escaping
else if let Some(&(i, _)) = iter.peek() { else if let Some(&(i, _)) = iter.peek() {
self.after_open_leaf = false; self.after_open_leaf = false;
let i1 = i; let i1 = i;
let i2 = { let i2 = {
let mut i2 = 0; let mut i2 = i1;
let mut escaped = false;
while let Some(&(i, c)) = iter.peek() { while let Some(&(i, c)) = iter.peek() {
if c != ']' { if escaped {
iter.next(); escaped = false;
} else { } else if c == '\\' {
escaped = true;
} else if c == ']' {
i2 = i; i2 = i;
break; break;
} }
iter.next();
} }
i2 i2
}; };
token = Some(Token::LeafContents(&self.text[i1..i2])); token = Some(Token::LeafContents((self.bytes_consumed + i1, &self.text[i1..i2])));
} }
// Finish up // Finish up
match iter.peek() { match iter.peek() {
Some(&(i, _)) => { Some(&(i, _)) => {
self.bytes_consumed += i;
self.text = &self.text[i..]; self.text = &self.text[i..];
} }
@ -218,7 +232,8 @@ impl<'a> Iterator for TokenIter<'a> {
/// /////////////////////////////////////////////////////////////
// ================================================================
/// Returns whether the given unicode character is whitespace or not. /// Returns whether the given unicode character is whitespace or not.
fn is_ws_char(c: char) -> bool { fn is_ws_char(c: char) -> bool {
@ -265,6 +280,9 @@ fn is_ident_char(c: char) -> bool {
// ================================================================
#[cfg(test)] #[cfg(test)]
mod tests { mod tests {
use super::{token_iter, Token}; use super::{token_iter, Token};
@ -272,21 +290,47 @@ mod tests {
#[test] #[test]
fn token_iter_1() { fn token_iter_1() {
let s = r#" let s = r#"
# This is a comment and should be skipped # This is a comment and should be skipped
MyThing $ident { # This is another comment MyThing $ident { # This is another comment
MyProp [Some content] MyProp [Some content]
} }
"#; "#;
let mut ti = token_iter(s); let mut ti = token_iter(s);
assert_eq!(ti.next(), Some(Token::TypeName("MyThing"))); assert_eq!(ti.next(), Some(Token::TypeName((67, "MyThing"))));
assert_eq!(ti.next(), Some(Token::Ident("$ident"))); assert_eq!(ti.next(), Some(Token::Ident((75, "$ident"))));
assert_eq!(ti.next(), Some(Token::OpenInner)); assert_eq!(ti.next(), Some(Token::OpenInner(82)));
assert_eq!(ti.next(), Some(Token::TypeName("MyProp"))); assert_eq!(ti.next(), Some(Token::TypeName((126, "MyProp"))));
assert_eq!(ti.next(), Some(Token::OpenLeaf)); assert_eq!(ti.next(), Some(Token::OpenLeaf(133)));
assert_eq!(ti.next(), Some(Token::LeafContents("Some content"))); assert_eq!(ti.next(), Some(Token::LeafContents((134, "Some content"))));
assert_eq!(ti.next(), Some(Token::CloseLeaf)); assert_eq!(ti.next(), Some(Token::CloseLeaf(146)));
assert_eq!(ti.next(), Some(Token::CloseInner)); assert_eq!(ti.next(), Some(Token::CloseInner(160)));
assert_eq!(ti.next(), None);
}
#[test]
fn token_iter_2() {
let s = r#"MyProp [Some content\] with \escaped \\characters]"#;
let mut ti = token_iter(s);
assert_eq!(ti.next(), Some(Token::TypeName((0, "MyProp"))));
assert_eq!(ti.next(), Some(Token::OpenLeaf(7)));
assert_eq!(ti.next(),
Some(Token::LeafContents((8, r#"Some content\] with \escaped \\characters"#))));
assert_eq!(ti.next(), Some(Token::CloseLeaf(49)));
assert_eq!(ti.next(), None);
}
#[test]
fn token_iter_3() {
let s = r#"MyThing $\ an\ ident\$\ with\\\{\[\ \#escaped\ content {}"#;
let mut ti = token_iter(s);
assert_eq!(ti.next(), Some(Token::TypeName((0, "MyThing"))));
assert_eq!(ti.next(),
Some(Token::Ident((8, r#"$\ an\ ident\$\ with\\\{\[\ \#escaped\ content"#))));
assert_eq!(ti.next(), Some(Token::OpenInner(55)));
assert_eq!(ti.next(), Some(Token::CloseInner(56)));
assert_eq!(ti.next(), None); assert_eq!(ti.next(), None);
} }
} }