Don't understand how it works.

git-svn-id: https://svn.tlawal.org/svn/monkey@11 f6afcba9-9ef1-4bdd-9b72-7484f5705bac

parser/parser.go

@@ -1,39 +0,0 @@
-/* NOTE(tijani): 
- * l_ in variables names stand for local_ identifiers. The reason is because I do not like
- * single letter variable names, but I also do not want to confuse the myself 
- * when I come back to reading this code after a while hence l_ to signify that it is local to that function.
-*/
-
-package parser
-
-import (
-	"monkey/ast"
-	"monkey/lexer"
-	"monkey/token"
-)
-
-type Parser struct {
-	l_lexer *lexer.Lexer
-	current_token token.Token
-	peek_token token.Token
-}
-
-func (l_parser *Parser) next_token(){
-	l_parser.current_token	 = l_parser.peek_token 
-	l_parser.peek_token = l_parser.l_lexer.NextToken() 
-}
-
-func (p *Parser) ParseProgram() *ast.Program {
-	return nil
-}
-
-func New(lexer *lexer.Lexer) *Parser {
-	l_parser := &Parser {l_lexer: lexer}
-	// Read two tokens so current_token and peek_token are set.
-	// NOTE(tijani): the first time l_parser.next_token() is called, current_token and peek_token will be pointing to the same token.
-	l_parser.next_token()
-	l_parser.next_token()
-
-	return l_parser
-}
-

parser/parser_test.go

@@ -1,64 +0,0 @@
-package parser
-
-import (
-	"testing"
-	"monkey/ast"
-	"monkey/lexer"
-)
-
-func TestLetStatement(t *testing.T) {
-	input := `
-				let x = 5;
-				let y = 10;
-				let foobar = 878688;
-	`
-	l_lexer := lexer.New(input)
-	l_parser := New(l_lexer)
-
-	program := l_parser.ParseProgram()
-	if program == nil {
-		t.Fatalf("ParseProgram() returned nil")
-	}
-	if len(program.Statements) != 3 {
-		t.Fatalf("program.Statements does not contain 3 statements, got=%d", len(program.Statements))
-	}
-
-	tests := []struct {
-		expectedIdentifier string
-	}{
-		{"x"},
-		{"y"},
-		{"foobar"},
-	}
-
-	for i, tt := range tests {
-		stmt := program.Statements[i]
-		if !testLetStatement(t, stmt, tt.expectedIdentifier) {
-			return
-		}
-	}
-}
-
-func testLetStatement(t *testing.T, s ast.Statement, name string) bool {
-	if s.TokenLiteral() != "let" {
-		t.Errorf("s.TokenLiteral not 'let', got=%q", s.TokenLiteral())
-		return false
-	}
-
-	letStmt, ok := s.(*ast.LetStatement)
-	if !ok {
-		t.Errorf("s not *ast.LetStatement, got=%T", s)
-		return false
-	}
-
-	if letStmt.Name.Value != name {
-		t.Errorf("letStmt.Name.Value not '%s', got=%s", name, letStmt.Name.Value)
-		return false
-	}
-
-	if letStmt.Name.TokenLiteral() != name {
-		t.Errorf("letStmt.Name.TokenLiteral() not '%s', got=%s", name, letStmt.Name.TokenLiteral())
-		return false
-	}
-	return true
-}