6 files changed, 267 insertions, 0 deletions
diff --git a/compilador/parse/base.py b/compilador/parse/base.py
new file mode 100644
index 0000000..a8f6f8a
--- /dev/null
+++ b/compilador/parse/base.py
@@ -0,0 +1,60 @@
+from enum import Enum
+from tabla import LexToken, TablaLex, tokens
+from arbol import Arbol, Nodo
+from shared import Control
+from pprint import pprint
+from errors import Error
+from typing import NoReturn
+from more_itertools import seekable
+
+from tabla import TablaLex, Token
+from errors import Error
+
+class BaseParser:
+    def __init__(self, iterador: seekable):
+        self.iterador: seekable = iterador
+
+    ''' Requires the next token to have a matching ltok. Returns that
+    token, or an error. '''
+    def want(self, *want: Token) -> (LexToken | Error):
+        tok: LexToken = self.lex()
+        if len(want) == 0:
+            return tok
+        for w in want:
+            if tok.tipo == w:
+                return tok
+
+        return Error.syntax(tok.tipo, want, tok.numlinea)
+
+    ''' Looks for a matching ltok from the lexer, and if not present,
+    unlexes the token and returns void. If found, the token is
+    consumed from the lexer and is returned. '''
+    def _try(self, *want: Token) -> (LexToken | NoReturn):
+        tok: LexToken = self.lex()
+        if len(want) == 0:
+            return tok
+        for w in want:
+            if tok.tipo == w:
+                return tok
+        self.unlex()
+
+    ''' Looks for a matching ltok from the lexer, unlexes the token,
+    and returns it; or void if it was not an ltok. '''
+    def peek(self, *want: Token) -> (LexToken | NoReturn):
+        tok: LexToken = self.iterador.peek()
+        if len(want) == 0:
+            return tok
+        for w in want:
+            if tok.tipo == w:
+                return tok
+
+    def lex(self):
+        return next(self.iterador)
+
+    def unlex(self):
+        self.iterador.seek(-1)
+
+    ''' Returns a syntax error if cond is false and void otherwise '''
+    def synassert(self, cond: bool, msg: str) -> (Error | NoReturn):
+        if not cond:
+            return Error(msg = msg)
diff --git a/compilador/parse/decl.py b/compilador/parse/decl.py
new file mode 100644
index 0000000..73f8580
--- /dev/null
+++ b/compilador/parse/decl.py
@@ -0,0 +1,102 @@
+from typing import List, cast, Optional
+from more_itertools import peekable
+
+from tabla import Token, LexToken
+from parse.base import BaseParser
+from errors import Error
+from parse.type import ParseType
+from parse.ident import ParseIdent
+from parse.expr import ParseExpr, Expr
+from astree.decl import DeclGlobal, DeclFunc, Decl
+
+class ParseDecl:
+    def __init__(self, parser: BaseParser):
+        self.parser = parser
+
+    def decl_global(self) -> (DeclGlobal | Error):
+        # Tipo
+        _type = ParseType(self.parser)._type()
+        if type(_type) is Error:
+            return _type
+
+        # Identificador
+        ident = ParseIdent(self.parser).ident()
+        if type(ident) is Error:
+            return ident
+
+        # =
+        init: Optional[Expr] = None
+        eq = self.parser._try(Token.EQUAL)
+        if eq:
+            # Expresión
+            init = ParseExpr(self.parser).expr()
+            if type(init) is Error:
+                return init
+
+        return DeclGlobal(ident = ident,
+                          _type = _type,
+                          init = init)
+
+    def decl_func(self) -> (DeclFunc | Error):
+        # funcion
+        tok = self.parser.want(Token.FUNCTION)
+        if type(tok) is Error:
+            return tok
+
+        # Tipo
+        _type = ParseType(self.parser)._type()
+        if type(_type) is Error:
+            return _type
+
+        # Identificador
+        ident = ParseIdent(self.parser).ident()
+        if type(ident) is Error:
+            return ident
+
+        # Prototipo
+        proto = ParseType(self.parser).prototype()
+        if type(proto) is Error:
+            return proto
+
+        # ;
+        # semicolon = self.parser.want(Token.SEMICOLON)
+        # if type(semicolon) is Error:
+        #     return semicolon
+        # self.parser.unlex()
+
+        return DeclFunc(ident = ident,
+                        prototype = proto,
+                        body = None)
+
+    # Parses a declaration.
+    def decl(self) -> (Decl | Error):
+        toks = [Token.BOOLEAN, Token.CHAR, Token.INT, Token.STRING, Token.VOID]
+        _next = self.parser.peek(*toks)
+        decl: Optional[Decl] = None
+        if not _next:
+            decl = self.decl_func()
+        else:
+            decl = self.decl_global()
+
+        if type(decl) is Error:
+            return decl
+
+        # ;
+        semicolon = self.parser.want(Token.SEMICOLON)
+        if type(semicolon) is Error:
+            return semicolon
+
+        return decl
+
+    # Parses the declarations for a sub-parser.
+    def decls(self) -> (List[Decl] | Error):
+        decls: List[Decl] = []
+        while not self.parser.peek(Token.EOF):
+            # print(self.parser.peek())
+            # print(next(self.parser.iterador))
+            decl = self.decl()
+            if type(decl) is Error:
+                return decl
+            decls.append(decl)
+
+        return decls
diff --git a/compilador/parse/expr.py b/compilador/parse/expr.py
new file mode 100644
index 0000000..a00f3d5
--- /dev/null
+++ b/compilador/parse/expr.py
@@ -0,0 +1,12 @@
+from parse.base import BaseParser
+from errors import Error
+from astree.expr import Expr
+
+class ParseExpr:
+    def __init__(self, parser: BaseParser):
+        self.parser = parser
+
+    def expr(self) -> Expr | Error:
+        next(self.parser.iterador)
+        return
+    
diff --git a/compilador/parse/ident.py b/compilador/parse/ident.py
new file mode 100644
index 0000000..5887fa2
--- /dev/null
+++ b/compilador/parse/ident.py
@@ -0,0 +1,15 @@
+
+from tabla import Token, LexToken
+from parse.base import BaseParser
+from astree.ident import Ident
+from errors import Error
+
+class ParseIdent:
+    def __init__(self, parser: BaseParser):
+        self.parser = parser
+
+    def ident(self) -> (Ident | Error):
+        tok: LexToken = self.parser.want(Token.IDENT)
+        if type(tok) is Error:
+            return tok
+        return tok.nombre
diff --git a/compilador/parse/type.py b/compilador/parse/type.py
new file mode 100644
index 0000000..27b83d3
--- /dev/null
+++ b/compilador/parse/type.py
@@ -0,0 +1,63 @@
+from typing import List
+
+from parse.base import BaseParser
+from lexer import LexToken, Token
+from astree.type import Type, BuiltinType, FuncType, FuncParam
+from errors import Error
+
+class ParseType:
+    def __init__(self, parser: BaseParser):
+        self.parser = parser
+
+    def _type(self) -> (Type | Error):
+        types = [Token.BOOLEAN, Token.CHAR, Token.INT, Token.STRING, Token.VOID]
+        tok = self.parser.want(*types)
+        if type(tok) is Error:
+            return tok
+        return BuiltinType(tok.tipo)
+
+    def prototype(self) -> (FuncType | Error):
+        params: List[FuncParam] = []
+
+        # Tipo
+        tok = ParseType(self.parser)._type()
+        if type(tok) is Error:
+            return tok
+        _type = tok
+
+        # (
+        tok = self.parser.want(Token.L_PAREN)
+        if type(tok) is Error:
+            return tok
+        while True:
+            tok = self.parser._try(Token.R_PAREN)
+            if not tok:
+                break
+
+            # Tipo
+            tok = ParseType(self.parser)._type()
+            if type(tok) is Error:
+                return tok
+            __type: Type = tok
+
+            # Identificador
+            tok = self.parser.want(Token.IDENT)
+            if type(tok) is Error:
+                return tok
+            name: str = tok
+
+            params.append(FuncParam(name = name,
+                                    _type = __type))
+
+            # ,
+            tok = self.parser._try(Token.COMMA)
+            if not tok:
+                continue
+
+            # )
+            tok = self.parser.want(Token.R_PAREN)
+            if type(tok) is Error:
+                return tok
+
+        return FuncType(result = _type,
+                        params = params)
diff --git a/compilador/parse/unit.py b/compilador/parse/unit.py
new file mode 100644
index 0000000..954b8b4
--- /dev/null
+++ b/compilador/parse/unit.py
@@ -0,0 +1,15 @@
+
+from errors import Error
+from astree.unit import Unit
+from parse.base import BaseParser
+from parse.decl import ParseDecl
+
+class ParseUnit:
+    def __init__(self, parser: BaseParser):
+        self.parser: BaseParser = parser
+
+    def unit(self) -> (Unit | Error):
+        decls = ParseDecl(self.parser).decls()
+        if type(decls) is Error:
+            return decls
+        return Unit(decls = decls)