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Diffstat (limited to 'examples/rosettacode.py')
| -rw-r--r-- | examples/rosettacode.py | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/examples/rosettacode.py b/examples/rosettacode.py new file mode 100644 index 0000000..07ed7fa --- /dev/null +++ b/examples/rosettacode.py @@ -0,0 +1,278 @@ +# +# rosettacode.py +# +# parser for language used by rosettacode.org (http://rosettacode.org/wiki/Compiler/syntax_analyzer) +# +# Copyright Paul McGuire, 2019 +# +BNF = """ + stmt_list = {stmt} ; + + stmt = ';' + | Identifier '=' expr ';' + | 'while' paren_expr stmt + | 'if' paren_expr stmt ['else' stmt] + | 'print' '(' prt_list ')' ';' + | 'putc' paren_expr ';' + | '{' stmt_list '}' + ; + + paren_expr = '(' expr ')' ; + + prt_list = string | expr {',' String | expr} ; + + expr = and_expr {'||' and_expr} ; + and_expr = equality_expr {'&&' equality_expr} ; + equality_expr = relational_expr [('==' | '!=') relational_expr] ; + relational_expr = addition_expr [('<' | '<=' | '>' | '>=') addition_expr] ; + addition_expr = multiplication_expr {('+' | '-') multiplication_expr} ; + multiplication_expr = primary {('*' | '/' | '%') primary } ; + primary = Identifier + | Integer + | '(' expr ')' + | ('+' | '-' | '!') primary + ; +""" + +import pyparsing as pp +pp.ParserElement.enablePackrat() + +LBRACE, RBRACE, LPAR, RPAR, SEMI = map(pp.Suppress, "{}();") +EQ = pp.Literal('=') + +keywords = (WHILE, IF, PRINT, PUTC, ELSE) = map(pp.Keyword, "while if print putc else".split()) +identifier = ~(pp.MatchFirst(keywords)) + pp.pyparsing_common.identifier +integer = pp.pyparsing_common.integer +string = pp.QuotedString('"', convertWhitespaceEscapes=False).setName("quoted string") +char = pp.Regex(r"'\\?.'") + +expr = pp.infixNotation(identifier | integer | char, + [ + (pp.oneOf("+ - !"), 1, pp.opAssoc.RIGHT,), + (pp.oneOf("* / %"), 2, pp.opAssoc.LEFT, ), + (pp.oneOf("+ -"), 2, pp.opAssoc.LEFT,), + (pp.oneOf("< <= > >="), 2, pp.opAssoc.LEFT,), + (pp.oneOf("== !="), 2, pp.opAssoc.LEFT,), + (pp.oneOf("&&"), 2, pp.opAssoc.LEFT,), + (pp.oneOf("||"), 2, pp.opAssoc.LEFT,), + ]) + +prt_list = pp.Group(pp.delimitedList(string | expr)) +paren_expr = pp.Group(LPAR + expr + RPAR) + +stmt = pp.Forward() +assignment_stmt = pp.Group(identifier + EQ + expr + SEMI) +while_stmt = pp.Group(WHILE - paren_expr + stmt) +if_stmt = pp.Group(IF - paren_expr + stmt + pp.Optional(ELSE + stmt)) +print_stmt = pp.Group(PRINT - pp.Group(LPAR + prt_list + RPAR) + SEMI) +putc_stmt = pp.Group(PUTC - paren_expr + SEMI) +stmt_list = pp.Group(LBRACE + pp.ZeroOrMore(stmt) + RBRACE) +stmt <<= (pp.Group(SEMI) + | assignment_stmt + | while_stmt + | if_stmt + | print_stmt + | putc_stmt + | stmt_list + ).setName("statement") + +code = pp.ZeroOrMore(stmt) +code.ignore(pp.cppStyleComment) + + +tests = [ + r''' + count = 1; + while (count < 10) { + print("count is: ", count, "\n"); + count = count + 1; + } + ''', + r''' + /* + Simple prime number generator + */ + count = 1; + n = 1; + limit = 100; + while (n < limit) { + k=3; + p=1; + n=n+2; + while ((k*k<=n) && (p)) { + p=n/k*k!=n; + k=k+2; + } + if (p) { + print(n, " is prime\n"); + count = count + 1; + } + } + print("Total primes found: ", count, "\n"); + ''', + r''' + /* + Hello world + */ + print("Hello, World!\n"); + ''', + r''' + /* + Show Ident and Integers + */ + phoenix_number = 142857; + print(phoenix_number, "\n"); + ''', + r''' + /*** test printing, embedded \n and comments with lots of '*' ***/ + print(42); + print("\nHello World\nGood Bye\nok\n"); + print("Print a slash n - \\n.\n"); + ''', + r''' + /* 100 Doors */ + i = 1; + while (i * i <= 100) { + print("door ", i * i, " is open\n"); + i = i + 1; + } + ''', + r''' + a = (-1 * ((-1 * (5 * 15)) / 10)); + print(a, "\n"); + b = -a; + print(b, "\n"); + print(-b, "\n"); + print(-(1), "\n"); + ''', + r''' + print(---------------------------------+++5, "\n"); + print(((((((((3 + 2) * ((((((2))))))))))))), "\n"); + + if (1) { if (1) { if (1) { if (1) { if (1) { print(15, "\n"); } } } } } + ''', + r''' + /* Compute the gcd of 1071, 1029: 21 */ + + a = 1071; + b = 1029; + + while (b != 0) { + new_a = b; + b = a % b; + a = new_a; + } + print(a); + ''', + r''' + /* 12 factorial is 479001600 */ + + n = 12; + result = 1; + i = 1; + while (i <= n) { + result = result * i; + i = i + 1; + } + print(result); + ''', + r''' + /* fibonacci of 44 is 701408733 */ + + n = 44; + i = 1; + a = 0; + b = 1; + while (i < n) { + w = a + b; + a = b; + b = w; + i = i + 1; + } + print(w, "\n"); + ''', + r''' + /* FizzBuzz */ + i = 1; + while (i <= 100) { + if (!(i % 15)) + print("FizzBuzz"); + else if (!(i % 3)) + print("Fizz"); + else if (!(i % 5)) + print("Buzz"); + else + print(i); + + print("\n"); + i = i + 1; + } + ''', + r''' + /* 99 bottles */ + bottles = 99; + while (bottles > 0) { + print(bottles, " bottles of beer on the wall\n"); + print(bottles, " bottles of beer\n"); + print("Take one down, pass it around\n"); + bottles = bottles - 1; + print(bottles, " bottles of beer on the wall\n\n"); + } + ''', + r''' + { + /* + This is an integer ascii Mandelbrot generator + */ + left_edge = -420; + right_edge = 300; + top_edge = 300; + bottom_edge = -300; + x_step = 7; + y_step = 15; + + max_iter = 200; + + y0 = top_edge; + while (y0 > bottom_edge) { + x0 = left_edge; + while (x0 < right_edge) { + y = 0; + x = 0; + the_char = ' '; + i = 0; + while (i < max_iter) { + x_x = (x * x) / 200; + y_y = (y * y) / 200; + if (x_x + y_y > 800 ) { + the_char = '0' + i; + if (i > 9) { + the_char = '@'; + } + i = max_iter; + } + y = x * y / 100 + y0; + x = x_x - y_y + x0; + i = i + 1; + } + putc(the_char); + x0 = x0 + x_step; + } + putc('\n'); + y0 = y0 - y_step; + } + } + ''', +] + +import sys +sys.setrecursionlimit(2000) + +for test in tests: + try: + results = code.parseString(test) + except pp.ParseException as pe: + pp.ParseException.explain(pe) + else: + results.pprint() + print() |