tijani
fdf6a8a552
- Parser can now handle return statements. git-svn-id: https://svn.tlawal.org/svn/monkey@21 f6afcba9-9ef1-4bdd-9b72-7484f5705bac
115 lines
2.5 KiB
Go
115 lines
2.5 KiB
Go
package parser
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import (
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"monkey/ast"
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"monkey/lexer"
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"testing"
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)
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func check_parser_errors(l_test *testing.T, l_parser *Parser) {
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errors := l_parser.Errors()
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if len(errors) == 0 {
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return
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}
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l_test.Errorf("parser has %d errors", len(errors))
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for _, message := range errors {
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l_test.Errorf("parser error: %q", message)
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}
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l_test.FailNow()
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}
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func TestLetStatement(l_test *testing.T) {
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input := `
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let x = 4;
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let y = 19;
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let foobar = 8948398493;
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`
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l_lexer := lexer.New(input)
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l_parser := New(l_lexer)
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program := l_parser.ParseProgram()
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check_parser_errors(l_test, l_parser)
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if program == nil {
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l_test.Fatalf("ParseProgram() returned nil")
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}
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if len(program.Statements) != 3 {
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l_test.Fatalf("program.Statements does not contain 3 statements, got=%d", len(program.Statements))
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}
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tests := []struct {
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expected_identifier string
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}{
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{"x"},
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{"y"},
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{"foobar"},
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}
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for i, tt := range tests {
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statement := program.Statements[i]
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if !testLetStatement(l_test, statement, tt.expected_identifier) {
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return
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}
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}
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}
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func testLetStatement(l_test *testing.T, statement ast.Statement, name string) bool {
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if statement.TokenLiteral() != "let" {
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l_test.Errorf("statement.TokenLiteral not let, got=%q", statement.TokenLiteral())
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return false
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}
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let_statement, ok := statement.(*ast.LetStatement)
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if !ok {
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l_test.Errorf("statement not *ast.LetStatement, got=%T", statement)
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return false
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}
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if let_statement.Name.Value != name {
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l_test.Errorf("let_statement.name.Value not %s, got=%s", name, let_statement.Name.Value)
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return false
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}
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if let_statement.Name.TokenLiteral() != name {
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l_test.Errorf("let_statement.name.TokenLiteral() not %s, got=%s", name, let_statement.Name.TokenLiteral())
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return false
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}
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return true
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}
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func TestReturnStatement(l_test *testing.T) {
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input := `
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return 6;
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return 10;
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return 8419849;
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`
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l_lexer := lexer.New(input)
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l_parser := New(l_lexer)
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program := l_parser.ParseProgram()
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check_parser_errors(l_test, l_parser)
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if len(program.Statements) != 3 {
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l_test.Fatalf("program.Statements does not contain 3 statements, got=%d", len(program.Statements))
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}
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for _, statement := range program.Statements {
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return_statement, ok := statement.(*ast.ReturnStatement)
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if !ok {
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l_test.Errorf("statment not *ast.ReturnStatement, got =%T", statement)
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continue
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}
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if return_statement.TokenLiteral() != "return" {
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l_test.Errorf("return_statement.TokenLiteral() not 'return', got %q", return_statement.TokenLiteral())
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}
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}
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}
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