class Drizzle::Parser

• Drizzle::Parser
• Reference
• Object

Overview

A Parser reads in the tokens generated by a Lexer and constructs an Abstract Syntax Tree (AST) built from what it finds.

Defined in:

drizzle/parser.cr

Constructors

• .new(lexer : Lexer)

Instance Method Summary

• #current : Drizzle::Token

  The token that is currently being inspected by the parser

• #eat?(expected_type : TokenType) : Bool

  "Eat" the @peek token if the expected type matches the type of @peek

• #eat_error(expected_type : TokenType)

  Add an error when #eat? gets an incorrect token type

• #errors : Array(String)

  Maintain an array of errors that are generated during the parsing step

• #initialise_parsers

  Initialize parser methods for the parser to use when parsing expressions

• #next_token

  Update the @current and @peek pointers contained in the Parser instance to the next token generated from the Lexer

• #parse_block_statement : AST::BlockStatement?

  Attempt to parse a block statement found at the current token, returning the node if possible, or nil if not

• #parse_boolean_literal : AST::Expression

  Parse a boolean found at the current token boolean

• #parse_call_arguments : Array(AST::Expression)

  Parse an argument list for a call expression (expression*)

• #parse_call_expression(left : AST::Expression) : AST::Expression

  Parse a call expression found at the current token identifier argument_list

• #parse_expression(precedence : Precedence) : AST::Expression?

  Attempt to parse an expression.

• #parse_expression_statement : AST::ExpressionStatement?

  Attempt to parse an expression statement found at the current token, returning the node if possible, or nil if not

• #parse_function : AST::Function?

  Attempt to parse a function found at the current token, returning the node if possible, or nil if not def name((name: type)*) -> type block

• #parse_function_parameters : Array(AST::TypedIdentifier)?

  Parse the parameter list for a function and return an array of AST::TypedIdentifier instances representing the parameters

• #parse_grouped_expression : AST::Expression?

  Parse a grouped expression found at the current token (expression)

• #parse_identifier : AST::Expression

  Parse an identifier found at the current token name

• #parse_if_statement(check_alternatives : Bool = true) : AST::IfStatement?

  Attempt to parse an 'if' statement found at the current token, returning the node if possible, or nil if not.

• #parse_infix_expression(left : AST::Expression) : AST::Expression

  Parse an infix expression found at the current token expression operator expression

• #parse_integer_literal : AST::Expression

  Parse an integer found at the current token integer

• #parse_let_statement : AST::Let?

  Attempt to parse a let statement found at the current token, returning the node if possible, or nil if not

• #parse_prefix_expression : AST::Expression

  Parse a prefix expression found at the current token operator expression

• #parse_program : AST::Program

  Parse a program and build a program node from it, and return it

• #parse_return_statement : AST::Return?

  Attempt to parse a return statement found at the current token, returning the node if possible, or nil if not

• #parse_statement : AST::Statement?

  Parse a statement found at @current and return it, or nil if no statement can be parsed

• #parse_typed_identifier : AST::TypedIdentifier?

  Parse a typed identifier found at the current token name: datatype

• #peek : Drizzle::Token

  A pointer to the next token coming up in the stream.

• #register_infix(token_type : TokenType, func : InfixParser)

  Register a TokenType with a parser function that is run when the TokenType is discovered in a spot for infix notation

• #register_prefix(token_type : TokenType, func : PrefixParser)

  Register a TokenType with a parser function that is run when the TokenType is discovered in a spot for prefix notation

Constructor Detail

Instance Method Detail