diff --git a/.gitignore b/.gitignore deleted file mode 100644 index 21fb2c6..0000000 --- a/.gitignore +++ /dev/null @@ -1,7 +0,0 @@ - __pycache__ -.DS_Store -*.o -*.log -*.dot -.env - diff --git a/README.md b/README.md deleted file mode 100644 index 6a80c49..0000000 --- a/README.md +++ /dev/null @@ -1,61 +0,0 @@ -# simple_interpreter (A python interpreter implemented in python.) -一个用 python 实现的简单python解释器，分版本（与分支对应）逐步实现一个简单的python解释器功能，适合初学者了解解释器的工作原理 - -## 版本说明 -为了方便渐进式学习进度，每一个版本都创建了一个独立的分支，比如 v1.0版本对应的分支名为 v1.0, 该分支只实现了 v1.0 的功能，以此类推，逐步进行功能迭代。 -### v1.0 -only support single-digit integers + - -支持整数的加法运算 -### v2.0 -support multi-digit integers +/-, support process whitespace - -支持加法减法，支持处理表达式中的空格 -### v3.0 -support to parse (recognize) and interpret arithmetic expressions that have any number of plus or minus operators in it, for example “7 - 3 + 2 - 1”. - -支持包含多个数字的加减表达式 -### v4.0 -support to parse and interpret arithmetic expressions with any number of multiplication and division operators in them, for example “7 * 4 / 2 * 3” - -支持包含多个数字的乘除表达式 -### v5.0 -support to handle valid arithmetic expressions containing integers and any number of addition, subtraction, multiplication, and division operators. - -支持包含多个数字的加减乘除混合表达式 -### v6.0 -support to evaluates arithmetic expressions that have different operators and parentheses. - -支持包含括号的混合表达式处理 -### v7.0 -using ASTs represent the operator-operand model of arithmetic expressions. -支持使用 AST (abstract syntax tree 抽象语法树）来表示算术表达式 -#### 语法树可视化 -```shell -python genastdot.py "7 + 3 * (10 / (12 / (3 + 1) - 1))" > ast.dot && dot -Tpng -o ast.png ast.dot -``` -![ast.png](ast.png) - -执行之前需要先按照dot, 参考：https://graphviz.org/ - -### v8.0 -support unary operators (+, -) -```shell - python genastdot.py "5---2" > ast.dot && dot -Tpng -o ast_v8.png ast.dot -``` -![ast_v8.png](ast_v8.png) - - -### v9.0 -support to handle python assignment statements. - -```shell -python interpreter.py assignments.txt -``` - -```shell -python genastdot.py assignments.txt > ast.dot && dot -Tpng -o ast_v9.png ast.dot -``` - -### v10.0 -增加符号表记录变量的定义，以处理使用未处理的变量 diff --git a/abs_syntax_tree.py b/abs_syntax_tree.py deleted file mode 100644 index 73d7a25..0000000 --- a/abs_syntax_tree.py +++ /dev/null @@ -1,78 +0,0 @@ -#!/usr/bin/env python -# -*- coding: utf-8 -*- - -""" -@file: abs_syntax_tree.py -@author: amazing coder -@date: 2024/8/28 -@desc: abstract-syntax tree (AST) 抽象语法树节点定义 -eg: 2 + 3 * 4 -mul_token = Token(MUL, '*') -plus_token = Token(PLUS, '+') -node_mul = BinOp(Num(Token(INTEGER, 3)), mul_token, Num(Token(INTEGER, 4))) -node_plus = BinOp(Num(Token(INTEGER, 2), plus_token, node_mul)) -""" - - -class AST(object): - """ - ASTs represent the operator-operand model. - 每一个 AST 节点都代表一个运算符和一个操作数 - """ - def __init__(self): - pass - - -class BinOp(AST): - """ - 二元运算符节点，也是非叶子节点，代表一个二元运算符 - 比如 2 + 3 这个表达式，2 和 3 都是叶子节点，+ 是二元运算符节点 - """ - def __init__(self, left, op, right): - self.left = left - self.token = self.op = op - self.right = right - - -class Num(AST): - """ - 数字节点, 也是叶子节点，代表一个数字 - """ - def __init__(self, token): - self.token = token - self.value = token.value - - -class UnaryOp(AST): - """ - 一元运算符节点，也是非叶子节点，代表一个一元运算符 - 比如 -2 这个表达式，- 是一元运算符节点，2 是叶子节点 - """ - def __init__(self, op, expr): - self.token = self.op = op - self.expr = expr - -class Assign(AST): - """ - 赋值运算符节点，也是非叶子节点，代表一个赋值运算符 - 比如 a = 2 这个表达式，a 是变量，2是值， 都是叶子节点，= 是赋值运算符节点 - """ - def __init__(self, left, op, right): - self.left = left - self.token = self.op = op - self.right = right - -class Var(AST): - """ - 变量节点，也是叶子节点，代表一个变量 - """ - def __init__(self, token): - self.token = token - self.value = token.value - -class NoOp(AST): - pass - -class Compound(AST): - def __init__(self): - self.children = [] \ No newline at end of file diff --git a/assignments.txt b/assignments.txt deleted file mode 100644 index f5cba79..0000000 --- a/assignments.txt +++ /dev/null @@ -1,5 +0,0 @@ -a=1.34 -b=2 -c=a+b -d=a+b-c -e=45+f \ No newline at end of file diff --git a/ast.png b/ast.png deleted file mode 100644 index d4ffb2d..0000000 Binary files a/ast.png and /dev/null differ diff --git a/ast_v8.png b/ast_v8.png deleted file mode 100644 index b784d91..0000000 Binary files a/ast_v8.png and /dev/null differ diff --git a/ast_v9.png b/ast_v9.png deleted file mode 100644 index 7089939..0000000 Binary files a/ast_v9.png and /dev/null differ diff --git a/func_test.py b/func_test.py deleted file mode 100644 index 6d0a32a..0000000 --- a/func_test.py +++ /dev/null @@ -1,59 +0,0 @@ -#!/usr/bin/env python -# -*- coding: utf-8 -*- - -""" -@file: func_test.py -@author: amazing coder -@date: 2024/8/29 -@desc: -""" -from spi_token import Token -from abs_syntax_tree import Num, BinOp, UnaryOp -from interpreter import Analyzer, Parser, Interpreter, INTEGER, MINUS - -def test_unary_op(): - """ - 测试一元运算符, text=6---1 - """ - text = '5---2' - six_tok = Num(Token(INTEGER, 5)) - one_tok = Num(Token(INTEGER, 2)) - minus_tok = Token(MINUS, '-') - exp_node = BinOp(six_tok, minus_tok, UnaryOp(minus_tok, UnaryOp(minus_tok, one_tok))) - interpreter = Interpreter(None) - print(interpreter.visit(exp_node)) - -def test_analyzer(): - """ - 测试语法分析器 - """ - text = "a=45" - print(text) - analyzer = Analyzer(text) - token = analyzer.get_next_token() - while token.symbol_type != 'EOF': - print(token) - token = analyzer.get_next_token() - -def test_interpret_py_statements(): - """ - 测试解释器 - """ - text = """a=1 - b=2 - c=a+b - d=a+b+c - e=45 - """ - print(text) - print(repr(text)) - analyzer = Analyzer(text) - parser = Parser(analyzer) - interpreter = Interpreter(parser) - interpreter.interpret() - print(interpreter.GLOBAL_SCOPE) - - - -if __name__ == '__main__': - test_interpret_py_statements() \ No newline at end of file diff --git a/genastdot.py b/genastdot.py deleted file mode 100644 index 9fd8895..0000000 --- a/genastdot.py +++ /dev/null @@ -1,119 +0,0 @@ -############################################################################### -# AST visualizer - generates a DOT file for Graphviz. # -# # -# To generate an image from the DOT file run $ dot -Tpng -o ast.png ast.dot # -# # -############################################################################### -import argparse -import textwrap - -from interpreter import Analyzer, Parser, NodeVisitor - - -class ASTVisualizer(NodeVisitor): - def __init__(self, parser): - self.parser = parser - self.ncount = 1 - self.dot_header = [textwrap.dedent("""\ - digraph astgraph { - node [shape=circle, fontsize=12, fontname="Courier", height=.1]; - ranksep=.3; - edge [arrowsize=.5] - - """)] - self.dot_body = [] - self.dot_footer = ['}'] - - def visit_Num(self, node): - s = ' node{} [label="{}"]\n'.format(self.ncount, node.token.value) - self.dot_body.append(s) - node._num = self.ncount - self.ncount += 1 - - def visit_BinOp(self, node): - s = ' node{} [label="{}"]\n'.format(self.ncount, node.op.value) - self.dot_body.append(s) - node._num = self.ncount - self.ncount += 1 - - self.visit(node.left) - self.visit(node.right) - - for child_node in (node.left, node.right): - s = ' node{} -> node{}\n'.format(node._num, child_node._num) - self.dot_body.append(s) - - def visit_UnaryOp(self, node): - s = ' node{} [label="unary {}"]\n'.format(self.ncount, node.op.value) - self.dot_body.append(s) - node._num = self.ncount - self.ncount += 1 - - self.visit(node.expr) - s = ' node{} -> node{}\n'.format(node._num, node.expr._num) - self.dot_body.append(s) - - def visit_Compound(self, node): - s = ' node{} [label="Compound"]\n'.format(self.ncount) - self.dot_body.append(s) - node._num = self.ncount - self.ncount += 1 - - for child in node.children: - self.visit(child) - s = ' node{} -> node{}\n'.format(node._num, child._num) - self.dot_body.append(s) - - def visit_Assign(self, node): - s = ' node{} [label="{}"]\n'.format(self.ncount, node.op.value) - self.dot_body.append(s) - node._num = self.ncount - self.ncount += 1 - - self.visit(node.left) - self.visit(node.right) - - for child_node in (node.left, node.right): - s = ' node{} -> node{}\n'.format(node._num, child_node._num) - self.dot_body.append(s) - - def visit_Var(self, node): - s = ' node{} [label="{}"]\n'.format(self.ncount, node.value) - self.dot_body.append(s) - node._num = self.ncount - self.ncount += 1 - - def visit_NoOp(self, node): - s = ' node{} [label="NoOp"]\n'.format(self.ncount) - self.dot_body.append(s) - node._num = self.ncount - self.ncount += 1 - - - def gendot(self): - tree = self.parser.parse() - self.visit(tree) - return ''.join(self.dot_header + self.dot_body + self.dot_footer) - - -def main(): - argparser = argparse.ArgumentParser( - description='Generate an AST DOT file.' - ) - argparser.add_argument( - 'fname', - help='Pascal source file' - ) - args = argparser.parse_args() - fname = args.fname - text = open(fname, 'r').read() - - lexer = Analyzer(text) - parser = Parser(lexer) - viz = ASTVisualizer(parser) - content = viz.gendot() - print(content) - - -if __name__ == '__main__': - main() \ No newline at end of file diff --git a/genptdot.py b/genptdot.py deleted file mode 100644 index f4792c8..0000000 --- a/genptdot.py +++ /dev/null @@ -1,198 +0,0 @@ -#!/usr/bin/env python -# -*- coding: utf-8 -*- - -""" -@file: genptdot.py -@author: amazing coder -@date: 2024/8/28 -@desc: -""" - -############################################################################### -# # -# Parse Tree visualizer # -# # -# To generate an image from the DOT file run: # -# $ dot -Tpng -o parsetree.png parsetree.dot # -# # -############################################################################### -import argparse -import textwrap - -from interpreter import PLUS, MINUS, MUL, DIV, INTEGER, LPAREN, RPAREN, Analyzer - - -class Node(object): - def __init__(self, name): - self.name = name - self.children = [] - - def add(self, node): - self.children.append(node) - - -class RuleNode(Node): - pass - - -class TokenNode(Node): - pass - - -class Parser(object): - """Parses the input and builds a parse tree.""" - - def __init__(self, lexer): - self.lexer = lexer - # set current token to the first token taken from the input - self.current_token = self.lexer.get_next_token() - - # Parse tree root - self.root = None - self.current_node = None - - def error(self): - raise Exception('Invalid syntax') - - def eat(self, token_type): - # compare the current token type with the passed token - # type and if they match then "eat" the current token - # and assign the next token to the self.current_token, - # otherwise raise an exception. - if self.current_token.symbol_type == token_type: - self.current_node.add(TokenNode(self.current_token.value)) - self.current_token = self.lexer.get_next_token() - else: - self.error() - - def factor(self): - """factor : INTEGER | LPAREN expr RPAREN""" - node = RuleNode('factor') - self.current_node.add(node) - _save = self.current_node - self.current_node = node - - token = self.current_token - if token.symbol_type == INTEGER: - self.eat(INTEGER) - elif token.symbol_type == LPAREN: - self.eat(LPAREN) - self.expr() - self.eat(RPAREN) - - self.current_node = _save - - def term(self): - """term : factor ((MUL | DIV) factor)*""" - node = RuleNode('term') - self.current_node.add(node) - _save = self.current_node - self.current_node = node - - self.factor() - - while self.current_token.symbol_type in (MUL, DIV): - token = self.current_token - if token.symbol_type == MUL: - self.eat(MUL) - elif token.symbol_type == DIV: - self.eat(DIV) - - self.factor() - - self.current_node = _save - - def expr(self): - """ - expr : term ((PLUS | MINUS) term)* - term : factor ((MUL | DIV) factor)* - factor : INTEGER | LPAREN expr RPAREN - """ - node = RuleNode('expr') - if self.root is None: - self.root = node - else: - self.current_node.add(node) - - _save = self.current_node - self.current_node = node - - self.term() - - while self.current_token.symbol_type in (PLUS, MINUS): - token = self.current_token - if token.symbol_type == PLUS: - self.eat(PLUS) - elif token.symbol_type == MINUS: - self.eat(MINUS) - - self.term() - - self.current_node = _save - - def parse(self): - self.expr() - return self.root - - -class ParseTreeVisualizer(object): - def __init__(self, parser): - self.parser = parser - self.ncount = 1 - self.dot_header = [textwrap.dedent("""\ - digraph astgraph { - node [shape=none, fontsize=12, fontname="Courier", height=.1]; - ranksep=.3; - edge [arrowsize=.5] - - """)] - self.dot_body = [] - self.dot_footer = ['}'] - - def bfs(self, node): - ncount = 1 - queue = [] - queue.append(node) - s = ' node{} [label="{}"]\n'.format(ncount, node.name) - self.dot_body.append(s) - node._num = ncount - ncount += 1 - - while queue: - node = queue.pop(0) - for child_node in node.children: - s = ' node{} [label="{}"]\n'.format(ncount, child_node.name) - self.dot_body.append(s) - child_node._num = ncount - ncount += 1 - s = ' node{} -> node{}\n'.format(node._num, child_node._num) - self.dot_body.append(s) - queue.append(child_node) - - def gendot(self): - tree = self.parser.parse() - self.bfs(tree) - return ''.join(self.dot_header + self.dot_body + self.dot_footer) - - -def main(): - argparser = argparse.ArgumentParser( - description='Generate a Parse Tree DOT file.' - ) - argparser.add_argument( - 'text', - help='Arithmetic expression (in quotes): "1 + 2 * 3"' - ) - args = argparser.parse_args() - text = args.text - - lexer = Lexer(text) - parser = Parser(lexer) - - viz = ParseTreeVisualizer(parser) - content = viz.gendot() - print(content) - - -if __name__ == '__main__': - main() \ No newline at end of file diff --git a/interpreter.py b/interpreter.py index c120f49..66bf101 100644 --- a/interpreter.py +++ b/interpreter.py @@ -5,408 +5,85 @@ @file: interpreter.py @author: amazing coder @date: 2024/8/24 -@desc: simple demo for python interpreter v2.0 -v1.0 : only support single-digit integers + -v2.0 : support multi-digit integers +/-, support process whitespace -v3.0 : support to parse (recognize) and interpret arithmetic expressions that have any number of plus or minus operators in it, for example “7 - 3 + 2 - 1”. -v4.0 : support to parse and interpret arithmetic expressions with any number of multiplication and division operators in them, for example “7 * 4 / 2 * 3” -v5.0 : support to handle valid arithmetic expressions containing integers and any number of addition, subtraction, multiplication, and division operators. -v6.0 : support to evaluates arithmetic expressions that have different operators and parentheses. -v7.0 : using ASTs represent the operator-operand model of arithmetic expressions. -v8.0 : support unary operators (+, -) -v9.0 : support to handle python assignment statements. -v10.0 : handle variable not defined error +@desc: simple demo for python interpreter v1.0 """ -import keyword -from abs_syntax_tree import BinOp, Num, UnaryOp, Var, NoOp, Compound, Assign -from spi_token import Token -from spi_symbol import VarSymbol, SymbolTable +INTEGER, PLUS, EOF = 'INTEGER', 'PLUS', 'EOF' +class Token(object): + def __init__(self, type, value): + self.type = type + self.value = value -INTEGER, FLOAT, PLUS, EOF, MINUS, MUL, DIV, LPAREN, RPAREN, ID, ASSIGN, REPL = 'INTEGER', 'FLOAT', 'PLUS', 'EOF', 'MINUS', 'MUL', 'DIV', 'LPAREN', 'RPAREN', 'ID', 'ASSIGN', 'REPL' -PYTHON_RESERVED_KEYWORDS = {key: Token(key, key) for key in keyword.kwlist} + def __str__(self): + return 'Token({type}, {value})'.format( + type=self.type, + value=repr(self.value) + ) + + def __repr__(self): + return self.__str__() + +class Interpreter(object): -class Analyzer(object): - """Lexical analyzer 表达式的语法解析器，用于将表达式解析成token流""" def __init__(self, text): self.text = text self.pos = 0 - self.current_char = self.text[self.pos] - - def error(self): - return SyntaxError("invalid syntax") + self.current_token = None - def advance(self): - """Advance the 'pos' pointer and set the 'current_char' variable.""" - self.pos += 1 - if self.pos > len(self.text) - 1: - self.current_char = None - else: - self.current_char = self.text[self.pos] - def skip_whitespace(self): - """Skip whitespace, tab, newline.""" - while self.current_char is not None and self.current_char.isspace(): - self.advance() - - def peek(self): - peek_pos = self.pos + 1 - if peek_pos > len(self.text) - 1: - return None - else: - return self.text[peek_pos] - - def number(self): - """return a multi-digit integer""" - result = '' - while self.current_char is not None and self.current_char.isdigit(): - result += self.current_char - self.advance() - if self.current_char == '.': - result += self.current_char - self.advance() - while self.current_char is not None and self.current_char.isdigit(): - result += self.current_char - self.advance() - return float(result) - else: - return int(result) - - def identifier(self): - """return a multi-digit identifier""" - result = '' - while self.current_char is not None and self.current_char.isalnum(): - result += self.current_char - self.advance() - - if result in PYTHON_RESERVED_KEYWORDS: - return self.error() - return Token(ID, result) + def error(self): + raise Exception('Error parsing input') def get_next_token(self): - """this function breaking a sentence apart into tokens.""" - while self.current_char is not None: - if self.current_char.isspace(): - self.skip_whitespace() - continue - if self.current_char.isdigit(): - number = self.number() - return Token(INTEGER, number) if isinstance(number, int) else Token(FLOAT, number) - if self.current_char == '+': - self.advance() - return Token(PLUS, '+') - if self.current_char == '-': - self.advance() - return Token(MINUS, '-') - if self.current_char == '*': - self.advance() - return Token(MUL, '*') - if self.current_char == '/': - self.advance() - return Token(DIV, '/') - if self.current_char == '(': - self.advance() - return Token(LPAREN, '(') - if self.current_char == ')': - self.advance() - return Token(RPAREN, ')') - if self.current_char.isalpha(): - return self.identifier() - if self.current_char == '=': - self.advance() - return Token(ASSIGN, '=') - if self.current_char == '\\' and self.peek() == 'n': - self.advance() - self.advance() - return Token(REPL, '\\n') - - self.error() - return Token(EOF, None) + text = self.text + if self.pos > len(text) - 1: + return Token(EOF, None) -class Parser(object): - def __init__(self, analyzer): - self.analyzer = analyzer - self.current_token = self.analyzer.get_next_token() + current_char = text[self.pos] + self.pos += 1 - def error(self): - raise Exception('Invalid Syntax') + if current_char.isdigit(): + return Token(INTEGER, int(current_char)) + if current_char == '+': + return Token(PLUS, current_char) + self.error() def eat(self, token_type): - """compare the current token type with the passed token type - and if they match then "eat" the current token and assign - the next token to the self.current_token, otherwise raise an exception.""" if self.current_token.type == token_type: - self.current_token = self.analyzer.get_next_token() + self.current_token = self.get_next_token() else: self.error() - def term(self): - """计算乘除表达块： factor((MUL|DIV) factor)* """ - node = self.factor() - while self.current_token.type in (MUL, DIV): - token = self.current_token - if self.current_token.type == MUL: - self.eat(MUL) - elif self.current_token.type == DIV: - self.eat(DIV) - node = BinOp(left=node, op=token, right=self.factor()) - return node - - def variable(self): - node = Var(self.current_token) - self.eat(ID) - return node - - def empty(self): - return NoOp() - - def assignment_statement(self): - """ - assignment_statement : variable ASSIGN expr - """ - left = self.variable() - token = self.current_token - self.eat(ASSIGN) - right = self.expr() - node = Assign(left=left, op=token, right=right) - return node - - def statement(self): - """statement : assignment_statement | empty""" - if self.current_token.type == ID: - node = self.assignment_statement() - else: - node = self.empty() - return node - - def statements(self): - """ - statements : statement - | statement REPL statement_list - """ - node = self.statement() - results = [node] - while self.current_token.type == ID: - results.append(self.statement()) - - return results - - def compound_statement(self): - """ - compound_statement : statement_list - """ - # self.eat(REPL) - nodes = self.statements() - # self.eat(REPL) - - root = Compound() - for node in nodes: - root.children.append(node) - return root - - def program(self): - """program : compound_statement """ - node = self.compound_statement() - return node - def expr(self): - """表达式解析：term((PLUS|MINUS) term)* . - expr : term ((PLUS | MINUS) term)* - term : factor ((MUL | DIV) factor)* - factor : INTEGER | LPAREN expr RPAREN | (PLUS|MINUS) factor - """ - node = self.term() - while self.current_token.type in (PLUS, MINUS): - token = self.current_token - if self.current_token.type == PLUS: - self.eat(PLUS) - elif self.current_token.type == MINUS: - self.eat(MINUS) - node = BinOp(left=node, op=token, right=self.term()) - return node - - def factor(self): - """返回参与运算的数，支持整型或者带括号的表达式 INTEGER | LPAREN expr RPAREN | (PLUS|MINUS) factor | variable""" - token = self.current_token - if self.current_token.type == PLUS: - self.eat(PLUS) - return UnaryOp(op=token, expr=self.factor()) - elif self.current_token.type == MINUS: - self.eat(MINUS) - return UnaryOp(op=token, expr=self.factor()) - elif self.current_token.type == INTEGER: - self.eat(INTEGER) - return Num(token) - elif self.current_token.type == FLOAT: - self.eat(FLOAT) - return Num(token) - elif self.current_token.type == LPAREN: - self.eat(LPAREN) - node = self.expr() - self.eat(RPAREN) - return node - elif self.current_token.type == ID: - node = self.variable() - return node - else: - self.error() - - def parse(self): - node = self.program() - if self.current_token.type != EOF: - self.error() - return node - - -class NodeVisitor(object): - def visit(self, node): - method_name = 'visit_' + type(node).__name__ - visitor = getattr(self, method_name, self.generic_visit) - return visitor(node) - - def generic_visit(self, node): - raise Exception('No visit_{} method'.format(type(node).__name__)) - - -class Interpreter(NodeVisitor): - def __init__(self, parser): - self.parser = parser - self.GLOBAL_SCOPE = {} - - def visit_BinOp(self, node): - if node.op.type == PLUS: - return self.visit(node.left) + self.visit(node.right) - elif node.op.type == MINUS: - return self.visit(node.left) - self.visit(node.right) - elif node.op.type == MUL: - return self.visit(node.left) * self.visit(node.right) - elif node.op.type == DIV: - return self.visit(node.left) / self.visit(node.right) - - def visit_Num(self, node): - return node.token.value - - def visit_UnaryOp(self, node): - if node.op.type == PLUS: - return self.visit(node.expr) - elif node.op.type == MINUS: - return -self.visit(node.expr) - - def visit_Assign(self, node): - var_name = node.left.value - self.GLOBAL_SCOPE[var_name] = self.visit(node.right) - - def visit_NoOp(self, node): - pass - - def visit_Compound(self, node): - for child in node.children: - self.visit(child) - - def visit_Var(self, node): - var_name = node.value - val = self.GLOBAL_SCOPE.get(var_name) - if val is None: - raise NameError(repr(var_name)) - else: - return val - - def visit(self, node): - if isinstance(node, BinOp): - return self.visit_BinOp(node) - elif isinstance(node, Num): - return self.visit_Num(node) - elif isinstance(node, UnaryOp): - return self.visit_UnaryOp(node) - elif isinstance(node, Var): - return self.visit_Var(node) - elif isinstance(node, Assign): - return self.visit_Assign(node) - elif isinstance(node, Compound): - return self.visit_Compound(node) - elif isinstance(node, NoOp): - return self.visit_NoOp(node) - - def interpret(self): - tree = self.parser.parse() - symbol_builder = SymbolTableBuilder() - symbol_builder.visit(tree) - return self.visit(tree) - - -class SymbolTableBuilder(NodeVisitor): - def __init__(self): - self.symtab = SymbolTable() - - def visit_BinOp(self, node): - self.visit(node.left) - self.visit(node.right) - - def visit_Num(self, node): - pass - - def visit_UnaryOp(self, node): - self.visit(node.expr) + self.current_token = self.get_next_token() + left = self.current_token + self.eat(INTEGER) - def visit_Compound(self, node): - for child in node.children: - self.visit(child) - - def visit_NoOp(self, node): - pass - - def visit_VarDecl(self, node): - type_name = node.type_node.value - type_symbol = self.symtab.lookup(type_name) - var_name = node.var_node.value - var_symbol = VarSymbol(var_name, type_symbol) - self.symtab.define(var_symbol) - - def visit_Assign(self, node): - # python代码中赋值就是定义，没有声明 - var_name = node.left.value - var_symbol = VarSymbol(var_name, None) - self.symtab.define(var_symbol) - self.visit(node.right) - - def visit_Var(self, node): - var_name = node.value - var_symbol = self.symtab.lookup(var_name) - if var_symbol is None: - raise NameError(repr(var_name)) - - def visit(self, node): - if isinstance(node, BinOp): - return self.visit_BinOp(node) - elif isinstance(node, Num): - return self.visit_Num(node) - elif isinstance(node, UnaryOp): - return self.visit_UnaryOp(node) - elif isinstance(node, Var): - return self.visit_Var(node) - elif isinstance(node, Assign): - return self.visit_Assign(node) - elif isinstance(node, Compound): - return self.visit_Compound(node) - elif isinstance(node, NoOp): - return self.visit_NoOp(node) + op = self.current_token + self.eat(PLUS) + right = self.current_token + self.eat(INTEGER) + result = left.value + right.value + return result def main(): - import sys - py_file = sys.argv[1] - # py_file = 'assignments.txt' - text = open(py_file, 'r').read() - print(f"begin parse input: {text}") - lexer = Analyzer(text) - parser = Parser(lexer) - interpreter = Interpreter(parser) - result = interpreter.interpret() - print(interpreter.GLOBAL_SCOPE) + while True: + try: + text = input('input a express like "1+2"(Only single digit integers are allowed in the input)> ') + except EOFError: + break + + if not text: + continue + interpreter = Interpreter(text) + result = interpreter.expr() + print(result) if __name__ == '__main__': main() + diff --git a/spi_symbol.py b/spi_symbol.py deleted file mode 100644 index 791cd08..0000000 --- a/spi_symbol.py +++ /dev/null @@ -1,69 +0,0 @@ -#!/usr/bin/env python -# -*- coding: utf-8 -*- - -""" -@file: spi_symbol.py -@author: amazing coder -@date: 2024/8/31 -@desc: 增加通用符号类 -""" - - -class Symbol(object): - def __int__(self, name, type=None): - self.name = name - self.symbol_type = type - - -class BuiltinTypeSymbol(Symbol): - def __init__(self, name): - super().__int__(name) - - def __str__(self): - return self.name - - __repr__ = __str__ - - -class VarSymbol(Symbol): - def __init__(self, name, type=None): - # python 定义时可以不指定类型 - super().__int__(name, type) - - def __str__(self): - return f'VarSymbol:name={self.name}: type={self.symbol_type}' - - __repr__ = __str__ - - -class SymbolTable(object): - def __init__(self): - self._symbols = {} - - def __str__(self): - return 'Symbols: {symbols}'.format(symbols=[value for value in self._symbols.values()]) - - __repr__ = __str__ - - def define(self, symbol): - print('Define: %s' % symbol) - self._symbols[symbol.name] = symbol - return symbol - - def lookup(self, name): - print('Lookup: %s' % name) - symbol = self._symbols.get(name) - return symbol - - -def test_class(): - int_type = BuiltinTypeSymbol('INTEGER') - float_type = BuiltinTypeSymbol('FLOAT') - var_x = VarSymbol('x', int_type) - var_y = VarSymbol('y', float_type) - print(var_x) - print(var_y) - - -if __name__ == '__main__': - test_class() diff --git a/spi_token.py b/spi_token.py deleted file mode 100644 index 87bada4..0000000 --- a/spi_token.py +++ /dev/null @@ -1,24 +0,0 @@ -#!/usr/bin/env python -# -*- coding: utf-8 -*- - -""" -@file: spi_token.py -@author: amazing coder -@date: 2024/8/29 -@desc: -""" - - -class Token(object): - def __init__(self, type, value): - self.type = type - self.value = value - - def __str__(self): - return 'Token({type}, {value})'.format( - type=self.type, - value=repr(self.value) - ) - - def __repr__(self): - return self.__str__()