fix(parser): update parser docstrings

This commit is contained in:
2026-05-22 09:46:24 +02:00
parent 12d762429d
commit 409d9f8fa6

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@@ -83,7 +83,23 @@ class MidasParser(Parser):
def type_declaration(self) -> SimpleTypeStmt | ComplexTypeStmt:
"""Parse a type declaration
A type declaration is written `type Name<TypeExpr, ...>` optionally followed by a brace-wrapped body
A type declaration can either be a simple type alias or a new complex type.
In either case, it can have an optional template expression after its name, wrapped in brackets.
A simple type alias is derived from a base type expression, and can have a optional constraint expression preceded by the `where` keyword.
A full simple type alias is thus written:
```
type Name[Template](TypeExpr) where Condition
```
A new complex type has a set of properties which are named, have a type and an optional constraint expression (also preceded by the `where` keyword).
A full complex type definition is thus written:
```
type Name[Template] {
prop1: TypeExpr1 where Condition1
prop2: TypeExpr2 where Condition2
...
}
```
Returns:
TypeStmt: the parsed type declaration statement
@@ -107,6 +123,13 @@ class MidasParser(Parser):
return ComplexTypeStmt(name=name, template=template, properties=properties)
def template_expr(self) -> TemplateExpr:
"""Parse a generic template expression
A template is written `[TypeExpr]`
Returns:
TemplateExpr: the parsed template expression
"""
self.consume(TokenType.LEFT_BRACKET, "Missing '[' before template expression")
type: TypeExpr = self.type_expr()
self.consume(TokenType.RIGHT_BRACKET, "Missing ']' after template expression")
@@ -115,6 +138,9 @@ class MidasParser(Parser):
def type_expr(self) -> TypeExpr:
"""Parse a type expression
A type is an identifier, optionally followed by a template expression.
It can also optionally be followed by a '?' to indicate a nullable type
Returns:
TypeExpr: the parsed type expression
"""
@@ -126,14 +152,33 @@ class MidasParser(Parser):
return TypeExpr(name=name, template=template, optional=optional)
def simple_type_expr(self) -> SimpleTypeExpr:
"""Parse a simple type expression
A simple type is just an identifier optionally followed by a '?'
Returns:
SimpleTypeExpr: the parsed simple type expression
"""
name: Token = self.consume(TokenType.IDENTIFIER, "Expected type name")
optional: bool = self.match(TokenType.QMARK)
return SimpleTypeExpr(name=name, optional=optional)
def constraint(self) -> Expr:
"""Parse a constraint
A constraint is basically a logical predicate
Returns:
Expr: the parsed constraint expression
"""
return self.and_()
def and_(self) -> Expr:
"""Parse a logical AND expression or a simpler expression
Returns:
Expr: the parsed expression
"""
expr: Expr = self.equality()
while self.match(TokenType.AND):
operator: Token = self.previous()
@@ -142,6 +187,11 @@ class MidasParser(Parser):
return expr
def equality(self) -> Expr:
"""Parse a logical equality expression or a simpler expression
Returns:
Expr: the parsed expression
"""
expr: Expr = self.comparison()
while self.match(TokenType.BANG_EQUAL, TokenType.EQUAL_EQUAL):
operator: Token = self.previous()
@@ -150,6 +200,11 @@ class MidasParser(Parser):
return expr
def comparison(self) -> Expr:
"""Parse a logical comparison expression or a simpler expression
Returns:
Expr: the parsed expression
"""
expr: Expr = self.unary()
while self.match(
TokenType.LESS,
@@ -163,6 +218,11 @@ class MidasParser(Parser):
return expr
def unary(self) -> Expr:
"""Parse a unary expression or a simpler expression
Returns:
Expr: the parsed expression
"""
if self.match(TokenType.MINUS):
operator: Token = self.previous()
right: Expr = self.unary()
@@ -170,6 +230,11 @@ class MidasParser(Parser):
return self.reference()
def reference(self) -> Expr:
"""Parse an attribute access expression or a simpler expression
Returns:
Expr: the parsed expression
"""
expr: Expr = self.primary()
while self.match(TokenType.DOT):
name: Token = self.consume(
@@ -179,6 +244,13 @@ class MidasParser(Parser):
return expr
def primary(self) -> Expr:
"""Parse a primary expression
This includes literals (booleans, numbers, etc.), wildcards, identifiers and grouped expressions
Returns:
Expr: the parsed expression
"""
if self.match(TokenType.FALSE):
return LiteralExpr(False)
if self.match(TokenType.TRUE):
@@ -209,7 +281,7 @@ class MidasParser(Parser):
property statements enclosed in curly braces
Returns:
TypeBodyStmt: the parsed type body expression
list[PropertyStmt]: the parsed type properties
"""
self.consume(TokenType.LEFT_BRACE, "Expected '{' to start type body")
properties: list[PropertyStmt] = []
@@ -221,7 +293,7 @@ class MidasParser(Parser):
def property_stmt(self) -> PropertyStmt:
"""Parse a property statement
A type property statement is written `name: Type`
A type property statement is written `name: Type` or `name: Type where Condition`
Returns:
PropertyStmt: the parsed property statement
@@ -235,6 +307,13 @@ class MidasParser(Parser):
return PropertyStmt(name=name, type=type, constraint=constraint)
def extend_declaration(self) -> ExtendStmt:
"""Parse an extension definition
An extension is written `extend Type { operations }`
Returns:
ExtendStmt: the parsed extension statement
"""
type: TypeExpr = self.type_expr()
self.consume(TokenType.LEFT_BRACE, "Expected '{' to start extend body")
operations: list[OpStmt] = []
@@ -246,7 +325,7 @@ class MidasParser(Parser):
def op_declaration(self) -> OpStmt:
"""Parse an operation definition
An operation is written `op <Type1> operator <Type2> = <Type3>` where `operator` can be any single token
An operation is written `op name(Type) -> Type`
Returns:
OpStmt: the parsed operation statement
@@ -264,12 +343,12 @@ class MidasParser(Parser):
return OpStmt(name=name, operand=operand, result=result)
def predicate_declaration(self) -> PredicateStmt:
"""Parse a type constraint declaration
"""Parse a predicate declaration
A constraint is written `constraint Name = constraint_expression`
A predicate is written `predicate Name(subject: Type) = constraint_expression`
Returns:
ConstraintStmt: the parsed constraint declaration statement
PredicateStmt: the parsed predicate declaration statement
"""
name: Token = self.consume(TokenType.IDENTIFIER, "Expected predicate name")
self.consume(TokenType.LEFT_PAREN, "Expected '(' before predicate subject")