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authorbnewbold <bnewbold@robocracy.org>2016-04-21 16:51:11 -0400
committerbnewbold <bnewbold@robocracy.org>2016-04-21 16:51:11 -0400
commit115ba20ce23d5917b5b88384c53509fd04a96512 (patch)
tree9404309df112c5821bd0b174bbb02f1cf466a9dc
parent010656f9ce275d12d8d6520d2443fa6d1d6e3b13 (diff)
downloadspectrum-115ba20ce23d5917b5b88384c53509fd04a96512.zip
spectrum-115ba20ce23d5917b5b88384c53509fd04a96512.tar.gz
rust: fix symbols by adding identifiers, and handle comments
-rw-r--r--rust/spectrum.rs33
1 files changed, 27 insertions, 6 deletions
diff --git a/rust/spectrum.rs b/rust/spectrum.rs
index 8a82a33..317dce2 100644
--- a/rust/spectrum.rs
+++ b/rust/spectrum.rs
@@ -27,6 +27,7 @@ enum SchemeExpr<'a> {
SchemeNum(f64),
SchemeBuiltin(&'a str),
SchemeSymbol(&'a str),
+ SchemeIdentifier(&'a str),
SchemeStr(&'a str),
SchemeProcedure(
Vec<&'a str>,
@@ -41,17 +42,21 @@ enum SchemeExpr<'a> {
fn is_scheme_whitespace(c: char) -> bool{
" \r\n".find(c) != None
}
+
fn is_scheme_sep(c: char) -> bool {
"()".find(c) != None
}
-fn is_valid_symbol(s: &str) -> bool {
+fn is_valid_identifier(s: &str) -> bool {
// TODO: this could be an 'any' or 'filter' call?
if s.len() == 0 {
return false;
}
+ if s.starts_with("-") || s.ends_with("-") {
+ return false;
+ }
for c in s.chars() {
- if !c.is_alphabetic() && c != '-' {
+ if !(c.is_alphabetic() || c == '-') {
return false;
}
}
@@ -63,6 +68,7 @@ fn scheme_tokenize<'a>(raw_str: &'a str) -> Result<Vec<&'a str>, &'static str> {
let mut ret = Vec::<&str>::new();
let mut food: usize = 0;
let mut quoted: bool = false;
+ let mut commented: bool = false;
for (i, c) in raw_str.chars().enumerate() {
if quoted {
if c == '"' && raw_str.chars().collect::<Vec<char>>()[i-1] != '\\' {
@@ -74,6 +80,14 @@ fn scheme_tokenize<'a>(raw_str: &'a str) -> Result<Vec<&'a str>, &'static str> {
} else {
food += 1;
}
+ } else if commented {
+ food = 0;
+ if c == '\n' {
+ commented = false;
+ }
+ } else if c == ';' {
+ commented = true;
+ food = 0;
} else if c == '"' {
if food > 0 {
return Err("unexpected quote char");
@@ -125,11 +139,16 @@ fn scheme_parse_token(token: &str) -> Result<SchemeExpr, &'static str> {
return Ok(SchemeExpr::SchemeStr(token));
}
- // If it's all alphas, must be a symbol
- if is_valid_symbol(token) {
+ // Is it a symbol?
+ if token.starts_with("'") && is_valid_identifier(&token[1..]) {
return Ok(SchemeExpr::SchemeSymbol(token));
}
+ // Else, we'll treat it as an identifier
+ if is_valid_identifier(token) {
+ return Ok(SchemeExpr::SchemeIdentifier(token));
+ }
+
return Err("unparsable token");
}
@@ -180,6 +199,7 @@ fn scheme_repr(ast: &SchemeExpr) -> Result<String, &'static str> {
&SchemeExpr::SchemeBuiltin(b)=> Ok(b.to_string()),
&SchemeExpr::SchemeStr(s)=> Ok(s.to_string()),
&SchemeExpr::SchemeSymbol(s)=> Ok(s.to_string()),
+ &SchemeExpr::SchemeIdentifier(s)=> Ok("'".to_string() + s),
&SchemeExpr::SchemeProcedure(ref binds, ref body, _) => {
let mut ret = "(lambda (".to_string();
for bind in binds {
@@ -253,7 +273,7 @@ fn lambda_action<'a>(list: &Vec<SchemeExpr<'a>>, ctx: HashMap<&'a str, SchemeExp
};
for bind in bind_list {
match bind {
- &SchemeExpr::SchemeSymbol(name) =>
+ &SchemeExpr::SchemeIdentifier(name) =>
binds.push(name),
_ => return Err("lambda binds must all be non-builtin symbols")
}
@@ -399,12 +419,13 @@ fn scheme_meaning<'a>(ast: &SchemeExpr<'a>, ctx: HashMap<&'a str, SchemeExpr<'a>
&SchemeExpr::SchemeFalse => Ok(ast.clone()),
&SchemeExpr::SchemeNull => Ok(ast.clone()),
&SchemeExpr::SchemeStr(_) => Ok(ast.clone()),
+ &SchemeExpr::SchemeSymbol(_) => Ok(ast.clone()),
&SchemeExpr::SchemeNum(_) => Ok(ast.clone()),
&SchemeExpr::SchemeBuiltin(_) => Ok(ast.clone()),
&SchemeExpr::SchemeProcedure(_, _, _) => Ok(ast.clone()),
&SchemeExpr::SchemeQuote(ref list)
=> Ok(SchemeExpr::SchemeList(list.clone())),
- &SchemeExpr::SchemeSymbol(sym) => match ctx.get(sym) {
+ &SchemeExpr::SchemeIdentifier(sym) => match ctx.get(sym) {
// the "lookup action"
Some(val) => Ok(val.clone()),
None => Err("symbol not defined"),