Move parser crate items around

Eventually add this back in some form

schala-lang/src/parsing/mod.rs

@@ -1,178 +1,38 @@
 #![allow(clippy::upper_case_acronyms)]
 
-//! # Parsing
-//! This module is where the recursive-descent parsing methods live.
-//!
-//!
-//! # Schala EBNF Grammar
-//! This document is the authoritative grammar of Schala, represented in something approximating
-//! Extended Backus-Naur form. Terminal productions are in "double quotes", or UPPERCASE
-//! if they represent a class of tokens rather than an specific string, or are otherwise
-//! unreprsentable in ASCII.
-//!
-//! ## Top level structure
-//!
-//! ```text
-//! program := (statement delimiter)* EOF
-//! delimiter := NEWLINE | ";"
-//! statement := expression | declaration | import | flow
-//! block := "{" (statement delimiter)* "}"
-//! declaration := annotation? declaration | bare_declaration
-//! bare_declaration := type_declaration | func_declaration | binding_declaration | impl_declaration | module
-//! ```
-//! ## Declarations
-//!
-//! ### Types
-//! ```text
-//! type_declaration := "type" type_declaration_body
-//! type_declaration_body := "alias" type_alias | "mut"? type_singleton_name "=" type_body
-//! type_alias := IDENTIFIER "=" type_name
-//! type_body := immediate_record | (variant_specifier ("|" variant_specifier)*)
-//! immediate_record := "{" typed_identifier_list "}"
-//! variant_specifier := IDENTIFIER | IDENTIFIER "{" typed_identifier_list "}" | IDENTIFIER "(" type_name* ")"
-//! typed_identifier_list := typed_identifier*
-//! typed_identifier := IDENTIFIER type_anno
-//! ```
-//! ### Functions
-//!
-//! ```text
-//! func_declaration := func_signature func_body
-//! func_body := ε | nonempty_func_body
-//! nonempty_func_body := "{" (statement delimiter)* "}"
-//! func_signature := "fn" func_name formal_param_list type_anno+
-//! func_name := IDENTIFIER | operator
-//! formal_param_list := "(" (formal_param ",")* ")"
-//! formal_param := IDENTIFIER type_anno+
-//! ```
-//!
-//! ### Variable bindings
-//! ```text binding_declaration := "let" "mut"? IDENTIFIER "=" expresion```
-//!
-//! ### Interfaces
-//!
-//! ```text
-//! interface_declaration := "interface" type_singleton_name signature_block
-//! impl_declaration := "impl" type_singleton_name decl_block | "impl" type_singleton_name "for" type_name decl_block
-//! decl_block := "{" (func_declaration)* "}"
-//! signature_block := "{" (func_signature)* "}"
-//! ```
-//!
-//! ### Type Annotations
-//!
-//! ```text
-//! type_anno := ":" type_name
-//! type_name := type_singleton_name | "(" type_names ")"
-//! type_names := ε | type_name (, type_name)*
-//! type_singleton_name = IDENTIFIER (type_params)*
-//! type_params := "<" type_name (, type_name)* ">"
-//! ```
-//!
-//! ## Expressions
-//! ```text
-//! expression := precedence_expr type_anno?
-//! precedence_expr := prefix_expr
-//! prefix_expr := prefix_op extended_expr
-//!
-//! prefix_op := "+" | "-" | "!" | "~" | ε
-//!
-//! extended_expr := primary (ε | index | call | access)*
-//! index := "[" (expression ("," expression)*) "]"
-//! call := "(" invocation_list ")"
-//! access := "." identifier
-//! primary := literal | paren_expr | if_expr | for_expr | while_expr | identifier_expr | lambda_expr | anonymous_struct | list_expr
-//! expr_or_block := "{" (statement delimiter)* "}" | expr
-//!
-//! invocation_list := invocation_argument ("," invocation_argument)* | ε
-//! invocation_argument := expression | IDENTIFIER "=" expression | "_"
-//! ```
-//! //TODO fix expressions, add accessor_expr as a new thing
-//!
-//! ### Primary expressions
-//!
-//! ```text
-//! list_expr := "[" (expression, ",")* "]"
-//! lambda_expr := "\\" lambda_param_list type_anno? nonempty_func_body
-//! lambda_param_list := formal_param_list |  formal_param
-//! paren_expr := "(" paren_inner ")"
-//! paren_inner := (expression ",")*
-//! identifier_expr := qualified_identifier | named_struct
-//! qualified_identifier := IDENTIFIER ("::" IDENTIFIER)*
-//! ```
-//!
-//! ## Literals
-//! ```text
-//! literal := "true" | "false" | number_literal | STR_LITERAL
-//! named_struct := qualified_identifier record_block
-//! record_block :=  "{" (record_entry, ",")* | "}" //TODO support anonymus structs, update syntax
-//! record_entry := IDENTIFIER ":" expression
-//! anonymous_struct := TODO
-//! number_literal := int_literal | float_literal
-//! int_literal = ("0x" | "0b") digits
-//! float_literal := digits ("." digits)
-//! digits := (digit_group underscore*)+
-//! digit_group := DIGIT+
-//! ```
-//!
-//! ### Patterns
-//! ```text
-//! pattern := "(" (pattern, ",")* ")" | simple_pattern
-//! simple_pattern := pattern_literal | record_pattern | tuple_struct_pattern
-//! pattern_literal := "true" | "false" | signed_number_literal | STR_LITERAL | qualified_identifier
-//! signed_number_literal := "-"? number_literal
-//! record_pattern := qualified_identifier "{" (record_pattern_entry, ",")* "}"
-//! record_pattern_entry := IDENTIFIER | IDENTIFIER ":" Pattern
-//! tuple_struct_pattern := qualified_identifier "(" (pattern, ",")* ")"
-//! ```
-//! ### If expressions
-//!
-//! TODO: it would be nice if the grammar could capture an incomplete precedence expr in the
-//! discriminator
-//!
-//! ```text
-//! if_expr := "if" discriminator if_expr_body
-//! if_expr_body := ("then" simple_conditional | "is" simple_pattern_match | cond_block)
-//! discriminator := ε | expression
-//! simple_conditional := expr_or_block else_case
-//! simple_pattern_match := pattern "then" simple_conditional
-//! else_case := "else" expr_or_block
-//!
-//! cond_block := "{" (cond_arm comma_or_delimiter)* "}"
-//! cond_arm := condition guard "then" expr_or_block | "else" expr_or_block
-//! condition := "is" pattern | operator precedence_expr | expression
-//! guard := "if" expression
-//! comma_or_delimiter := "," | delimiter
-//! ```
-//!
-//!
-//! ### While expressions
-//! ```text
-//! while_expr := "while" while_cond "{" (statement delimiter)* "}"
-//! while_cond := ε | expression | expression "is"  pattern //TODO maybe is-expresions should be primary
-//! ```
-//!
-//! //TODO this implies there must be at least one enumerator, which the parser doesn"t support right
-//! //this second, and maybe should fail later anyway
-//! ### For-expressions
-//! ```text
-//! for_expr := "for" (enumerator | "{" enumerators "}") for_expr_body
-//! for_expr_body := "return" expression |  "{" (statement delimiter)* "}"
-//! enumerators := enumerator ("," enumerators)*
-//! enumerator :=  identifier "<-" expression | identifier "=" expression //TODO add guards, etc.
-//! ```
-//! ## Imports
-//! ```text
-//! import := 'import' IDENTIFIER (:: IDENTIFIER)*  import_suffix
-//! import_suffix := ε | '::{' IDENTIFIER (, IDENTIFIER)* '}' | '*' //TODO add qualified, exclusions, etc.
-//!
-//! ## Modules
-//!
-//! module := 'module' IDENTIFIER '{' statement* '}'
-//! ```
-pub mod new;
+mod new;
 mod test;
 
 use std::fmt;
 
+use crate::{
+    ast::{ASTItem, AST},
+    identifier::{Id, IdStore},
+};
+
+pub struct Parser {
+    id_store: IdStore<ASTItem>,
+}
+
+impl Parser {
+    pub(crate) fn new() -> Self {
+        Self { id_store: IdStore::new() }
+    }
+
+    pub(crate) fn parse(&mut self, input: &str) -> Result<AST, ParseError> {
+        use peg::str::LineCol;
+
+        new::schala_parser::program(input, self).map_err(|err: peg::error::ParseError<LineCol>| {
+            let msg = err.to_string();
+            ParseError { msg, location: err.location.offset.into() }
+        })
+    }
+
+    fn fresh(&mut self) -> Id<ASTItem> {
+        self.id_store.fresh()
+    }
+}
+
 /// Represents a parsing error
 #[derive(Debug)]
 pub struct ParseError {

schala-lang/src/parsing/new.rs

@@ -1,40 +1,14 @@
 use std::rc::Rc;
 
+use super::Parser;
 //TODO make use of the format_parse_error function
 //use crate::error::{SchalaError, format_parse_error};
-use crate::{
-    ast::*,
-    identifier::{Id, IdStore},
-    parsing::ParseError,
-};
+use crate::ast::*;
 
 fn rc_string(s: &str) -> Rc<String> {
     Rc::new(s.to_string())
 }
 
-pub struct Parser {
-    id_store: IdStore<ASTItem>,
-}
-
-impl Parser {
-    pub(crate) fn new() -> Self {
-        Self { id_store: IdStore::new() }
-    }
-
-    pub(crate) fn parse(&mut self, input: &str) -> Result<AST, ParseError> {
-        use peg::str::LineCol;
-
-        schala_parser::program(input, self).map_err(|err: peg::error::ParseError<LineCol>| {
-            let msg = err.to_string();
-            ParseError { msg, location: err.location.offset.into() }
-        })
-    }
-
-    fn fresh(&mut self) -> Id<ASTItem> {
-        self.id_store.fresh()
-    }
-}
-
 enum ExtendedPart<'a> {
     Index(Vec<Expression>),
     Accessor(&'a str),
@@ -83,6 +57,7 @@ peg::parser! {
             "break" { FlowControl::Break } /
             "return" _ expr:expression(parser)? { FlowControl::Return(expr) }
 
+            //TODO add the ability to rename and exclude imports
         rule import(parser: &mut Parser) -> ImportSpecifier =
             "import" _ path_components:path_components() suffix:import_suffix()? {
                 ImportSpecifier {
@@ -351,7 +326,7 @@ peg::parser! {
             }
 
 
-        //TODO anonymous structs, update syntax for structs
+        //TODO support anonymous structs and Elm-style update syntax for structs
         rule record_block(parser: &mut Parser) -> Vec<(&'input str, Expression)> =
             "{" _ entries:(record_entry(parser) ** ",") _ "}" { entries }
 

schala-lang/src/parsing/test.rs

@@ -6,7 +6,7 @@ use std::{fmt::Write, rc::Rc};
 
 use pretty_assertions::assert_eq;
 
-use super::new::{schala_parser, Parser};
+use super::{new::schala_parser, Parser};
 use crate::{ast::*, parsing::Location};
 
 fn rc(s: &str) -> Rc<String> {

schala-lang/src/schala.rs

@@ -17,7 +17,7 @@ pub struct Schala<'a> {
     /// Contains information for type-checking
     type_context: type_inference::TypeContext,
     /// Schala Parser
-    active_parser: parsing::new::Parser,
+    active_parser: parsing::Parser,
 
     /// Execution state for AST-walking interpreter
     eval_state: tree_walk_eval::State<'a>,
@@ -45,7 +45,7 @@ impl<'a> Schala<'a> {
             source_reference: SourceReference::new(),
             symbol_table: symbol_table::SymbolTable::new(),
             type_context: type_inference::TypeContext::new(),
-            active_parser: parsing::new::Parser::new(),
+            active_parser: parsing::Parser::new(),
             eval_state: tree_walk_eval::State::new(),
             timings: Vec::new(),
         }

schala-lang/src/util.rs

@@ -52,7 +52,7 @@ where T: Hash + Eq
 /// Quickly create an AST from a string, with no error checking. For test use only
 #[cfg(test)]
 pub fn quick_ast(input: &str) -> crate::ast::AST {
-    let mut parser = crate::parsing::new::Parser::new();
+    let mut parser = crate::parsing::Parser::new();
     let output = parser.parse(input);
     output.unwrap()
 }