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-rw-r--r--src/parse.rs297
1 files changed, 0 insertions, 297 deletions
diff --git a/src/parse.rs b/src/parse.rs
deleted file mode 100644
index 1dabd47..0000000
--- a/src/parse.rs
+++ /dev/null
@@ -1,297 +0,0 @@
-use std::fmt;
-
-use crate::lex::*;
-use crate::ast::*;
-use crate::ast::Binding::*;
-use crate::ast::Control::*;
-use crate::ast::Pattern::*;
-use Token::*;
-use Literal::*;
-use Punctuation::*;
-
-type Input = std::iter::Peekable<std::vec::IntoIter<Token>>;
-
-#[derive(Clone, Copy)]
-struct State {
- depth: usize,
- step: usize
-}
-
-impl State {
- fn indent(&self) -> State {
- State { depth: self.depth + self.step, step: self.step }
- }
- fn dedent(&self) -> State {
- State { depth: self.depth - self.step, step: self.step }
- }
-}
-
-/// Convert a basic TokenStream into an AbstractSyntaxTree
-pub fn astify(input: TokenStream, name: &str) -> Result<Expr> {
- let mut input = input.into_iter().peekable();
- let body = parse_body(&mut input, State { depth: 0, step: 0 })?;
- Ok(Expr::Binding(Module{ id: name.to_string(), body }))
-}
-
-/// Parse a series of Exprs, for ex. the body of a function.
-fn parse_body(input: &mut Input, state: State) -> Result<Vec<Expr>> {
- let mut res = Vec::new();
- while input.peek() == Some(&Indent(state.depth)) {
- input.next();
- res.push(parse_expr(input, state)?);
- }
- Ok(res)
-}
-
-/// Expr ::= Let | Var | Const | Func | Type |
-/// Mod | Import | Block | Static |
-/// For | While | Loop | If | When | Try | Match
-fn parse_expr(input: &mut Input, state: State) -> Result<Expr> {
- use Keyword::*;
- match input.next() {
- Some(Key(word)) => match word {
- Pub => {
- match input.next() {
- Some(Key(word)) => match word {
- Const => parse_const(input, state, true),
- Func => parse_funcdecl(input, state, true),
- Type => parse_typedecl(input, state, true),
- Mod => parse_mod(input, state, true),
- _ => return Err("unrecognized keyword following pub".into()),
- }
- Some(_) => return Err("unrecognized thing following pub".into()),
- None => return Err("end of input".into()),
- }
- },
- Let => parse_let(input, state),
- Var => parse_var(input, state),
- Const => parse_const(input, state, false),
- Func => parse_funcdecl(input, state, false),
- Type => parse_typedecl(input, state, false),
- Mod => parse_mod(input, state, false),
- From => parse_import(input, state, true),
- Import => parse_import(input, state, false),
- Block => parse_block(input, state),
- Static => parse_static(input, state),
- For => parse_for(input, state),
- While => parse_while(input, state),
- Loop => parse_loop(input, state),
- If => parse_if(input, state),
- When => parse_when(input, state),
- Try => parse_try(input, state),
- Match => parse_match(input, state),
- _ => return Err("invalid keyword starting expression".into()),
- },
- _ => todo!(), // what can i do with this?? match line here
- }
-}
-
-/// Let ::= 'let' Pattern Annotation? '=' Expr
-fn parse_let(input: &mut Input, state: State) -> Result<Expr> {
- let id = parse_pattern(input, state)?;
- let mut kind = None;
- if let Some(Sep(Colon)) = input.peek() {
- input.next();
- kind = Some(parse_typedesc(input, state)?);
- }
- if input.next() != Some(Sep(Equals)) {
- return Err("= not following binding".into())
- }
- let value = Box::new(parse_expr(input, state)?);
- Ok(Expr::Binding(Let { id, kind, value }))
-}
-/// Var ::= 'var' Pattern Annotation? ('=' Expr)?
-fn parse_var(input: &mut Input, state: State) -> Result<Expr> {
- let id = parse_pattern(input, state)?;
- let mut kind = None;
- if let Some(Sep(Colon)) = input.peek() {
- input.next();
- kind = Some(parse_typedesc(input, state)?);
- }
- let mut value = None;
- if input.next() != Some(Sep(Equals)) {
- value = Some(Box::new(parse_expr(input, state)?));
- }
- Ok(Expr::Binding(Var { id, kind, value }))
-}
-// Const ::= 'pub'? 'const' Pattern Annotation? '=' Expr
-fn parse_const(input: &mut Input, state: State, public: bool) -> Result<Expr> {
- let id = parse_pattern(input, state)?;
- let mut kind = None;
- if let Some(Sep(Colon)) = input.peek() {
- input.next();
- kind = Some(parse_typedesc(input, state)?);
- }
- if input.next() != Some(Sep(Equals)) {
- return Err("= not following binding".into())
- }
- let value = Box::new(parse_expr(input, state)?);
- Ok(Expr::Binding(Const { public, id, kind, value }))
-}
-// Func ::= 'pub'? ('func' | 'proc') Ident Generics? Parameters? (':' TypeDesc) '=' Body
-fn parse_funcdecl(input: &mut Input, state: State, public: bool) -> Result<Expr> { todo!() }
-// TypeDecl ::= 'pub'? 'type' Pattern Generics? '=' 'distinct'? 'ref'? TypeDesc
-fn parse_typedecl(input: &mut Input, state: State, public: bool) -> Result<Expr> {
- let pattern = parse_pattern(input, state)?;
- todo!()
-}
-// Mod ::= 'pub'? 'mod' Ident ':' Body
-fn parse_mod(input: &mut Input, state: State, public: bool) -> Result<Expr> {
- match input.next() {
- Some(Word(id)) => {
- match input.next() {
- Some(Sep(Colon)) => {
- let body = parse_body(input, state.indent())?;
- Ok(Expr::Binding(Module { id, body }))
- },
- _ => return Err("unexpected token following mod label".into()),
- }
- },
- _ => return Err("unexpected thing following mod keyword".into()),
- }
-}
-
-// Import ::= ('from' Ident)? 'import' Ident (',' Ident)* ('as' Ident)?
-fn parse_import(input: &mut Input, state: State, from_scope: bool) -> Result<Expr> {
- let mut from = None;
- if from_scope {
- match input.next() {
- Some(Word(id)) => from = Some(id),
- _ => return Err("identifier not following from keyword".into())
- }
- if input.next() != Some(Key(Keyword::Import)) {
- return Err("expected import to follow from".into())
- }
- }
- todo!()
-}
-// Block ::= 'block' Ident? ':' Body
-fn parse_block(input: &mut Input, state: State) -> Result<Expr> { // todo: body + offset
- match input.next() {
- Some(Sep(Colon)) => {
- let id = None;
- let body = parse_body(input, state.indent())?;
- Ok(Expr::Control(Block { id, body }))
- },
- Some(Word(label)) => {
- match input.next() {
- Some(Sep(Colon)) => {
- let id = Some(label);
- let body = parse_body(input, state.indent())?;
- Ok(Expr::Control(Block { id, body }))
- },
- _ => return Err("unexpected token following block label".into()),
- }
- },
- _ => return Err("unexpected thing following block keyword".into()),
- }
-}
-// Static ::= 'static' ':' Body
-fn parse_static(input: &mut Input, state: State) -> Result<Expr> {
- if input.next() != Some(Sep(Colon)) {
- return Err("colon must follow static invocation".into());
- }
- let body = parse_body(input, state.indent())?;
- Ok(Expr::Control(Static { body }))
-}
-
-// For ::= 'for' Pattern 'in' Expr ':' Body
-fn parse_for(input: &mut Input, state: State) -> Result<Expr> {
- let binding = parse_pattern(input, state)?;
- if input.next() != Some(Key(Keyword::In)) {
- return Err("expected in keyword after for pattern".into());
- }
- let range = Box::new(parse_expr(input, state)?);
- if input.next() != Some(Sep(Colon)) {
- return Err("expected colon after in expression".into());
- }
- let body = parse_body(input, state.indent())?;
- Ok(Expr::Control(For { binding, range, body }))
-}
-// While ::= 'while' Expr ':' Body
-fn parse_while(input: &mut Input, state: State) -> Result<Expr> {
- let cond = Box::new(parse_expr(input, state)?);
- if input.next() != Some(Sep(Colon)) {
- return Err("expected colon after while keyword".into());
- }
- let body = parse_body(input, state.indent())?;
- Ok(Expr::Control(While { cond, body }))
-}
-// Loop ::= 'loop' ':' Body
-fn parse_loop(input: &mut Input, state: State) -> Result<Expr> {
- if input.next() != Some(Sep(Colon)) {
- return Err("expected colon after loop keyword".into());
- }
- let body = parse_body(input, state.indent())?;
- Ok(Expr::Control(Loop { body }))
-}
-
-// If ::= 'if' Expr ':' Body ('elif' Expr ':' Body)* ('else' ':' Body)?
-fn parse_if(input: &mut Input, state: State) -> Result<Expr> {
- let mut branches = Vec::new();
- branches.push(parse_cond_branch(input, state)?);
- while input.peek() == Some(&Key(Keyword::Elif)) {
- input.next();
- branches.push(parse_cond_branch(input, state)?);
- }
- let mut else_body = None;
- if input.peek() == Some(&Key(Keyword::Else)) {
- input.next();
- else_body = Some(parse_body(input, state.indent())?);
- }
- Ok(Expr::Control(If { branches, else_body }))
-}
-// When ::= 'when' Expr ':' Body ('elif' Expr ':' Body)* ('else' ':' Body)?
-fn parse_when(input: &mut Input, state: State) -> Result<Expr> {
- let mut branches = Vec::new();
- branches.push(parse_cond_branch(input, state)?);
- while input.peek() == Some(&Key(Keyword::Elif)) {
- input.next();
- branches.push(parse_cond_branch(input, state)?);
- }
- let mut else_body = None;
- if input.peek() == Some(&Key(Keyword::Else)) {
- input.next();
- else_body = Some(parse_body(input, state.indent())?);
- }
- let mut body = Vec::new();
- body.push(Expr::Control(If { branches, else_body }));
- Ok(Expr::Control(Static { body }))
-}
-// Try ::= 'try' ':' Body ('except' Ident (',' Ident)* ':' Body) ('finally' ':' Body)?
-fn parse_try(input: &mut Input, state: State) -> Result<Expr> {
- if input.next() != Some(Sep(Colon)) {
- return Err("expected colon after try keyword".into());
- }
- let body = parse_body(input, state.indent())?;
- let catches = Vec::new();
- while input.peek() == Some(&Key(Keyword::Catch)) {
- input.next();
- todo!();
- }
- let mut finally = None;
- if input.peek() == Some(&Key(Keyword::Finally)) {
- input.next();
- if input.next() != Some(Sep(Colon)) {
- return Err("expected colon after try keyword".into());
- }
- finally = Some(parse_body(input, state.indent())?);
- }
- Ok(Expr::Control(Try { body, catches, finally }))
-}
-// Match ::= 'match' Expr ('of' Pattern (',' Pattern)* ('where' Expr)? ':' Body)+
-fn parse_match(input: &mut Input, state: State) -> Result<Expr> {
- let item = parse_pattern(input, state)?;
- let mut branches = Vec::new();
- while input.peek() == Some(&Key(Keyword::Of)) {
- input.next();
- todo!();
- }
- Ok(Expr::Control(Match { item, branches }))
-}
-
-fn parse_typedesc(input: &mut Input, state: State) -> Result<Type> { todo!() }
-fn parse_pattern(input: &mut Input, state: State) -> Result<Pattern> { todo!() }
-fn parse_cond_branch(input: &mut Input, state: State) -> Result<CondBranch> { todo!() }
-
-// lex, parse, expand, compile?
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-26 07:39:35 +0000