PL0 whitespace handling improvement

db4
Chris Double 2008-04-02 15:47:30 +13:00
parent bbcc84862f
commit 34a1505d95
2 changed files with 65 additions and 35 deletions

View File

@ -4,40 +4,40 @@
USING: kernel tools.test peg peg.pl0 multiline sequences words assocs ;
IN: peg.pl0.tests
{ f } [
"CONST foo = 1;" \ pl0 "ebnf-parser" word-prop "block" swap at parse not
{ t } [
"CONST foo = 1;" \ pl0 "ebnf-parser" word-prop "block" swap at parse parse-result-remaining empty?
] unit-test
{ f } [
"VAR foo;" \ pl0 "ebnf-parser" word-prop "block" swap at parse not
{ t } [
"VAR foo;" \ pl0 "ebnf-parser" word-prop "block" swap at parse parse-result-remaining empty?
] unit-test
{ f } [
"VAR foo,bar , baz;" \ pl0 "ebnf-parser" word-prop "block" swap at parse not
{ t } [
"VAR foo,bar , baz;" \ pl0 "ebnf-parser" word-prop "block" swap at parse parse-result-remaining empty?
] unit-test
{ f } [
"foo := 5;" \ pl0 "ebnf-parser" word-prop "statement" swap at parse not
{ t } [
"foo := 5" \ pl0 "ebnf-parser" word-prop "statement" swap at parse parse-result-remaining empty?
] unit-test
{ f } [
"BEGIN foo := 5; END" \ pl0 "ebnf-parser" word-prop "statement" swap at parse not
{ t } [
"BEGIN foo := 5 END" \ pl0 "ebnf-parser" word-prop "statement" swap at parse parse-result-remaining empty?
] unit-test
{ f } [
"IF 1=1 THEN foo := 5; END" \ pl0 "ebnf-parser" word-prop "statement" swap at parse not
{ t } [
"IF 1=1 THEN foo := 5" \ pl0 "ebnf-parser" word-prop "statement" swap at parse parse-result-remaining empty?
] unit-test
{ f } [
"WHILE 1=1 DO foo := 5; END" \ pl0 "ebnf-parser" word-prop "statement" swap at parse not
{ t } [
"WHILE 1=1 DO foo := 5" \ pl0 "ebnf-parser" word-prop "statement" swap at parse parse-result-remaining empty?
] unit-test
{ f } [
"WHILE ODD 1=1 DO foo := 5; END" \ pl0 "ebnf-parser" word-prop "statement" swap at parse not
{ t } [
"WHILE ODD 1 DO foo := 5" \ pl0 "ebnf-parser" word-prop "statement" swap at parse parse-result-remaining empty?
] unit-test
{ f } [
"PROCEDURE square; BEGIN squ=x*x END" \ pl0 "ebnf-parser" word-prop "block" swap at parse not
{ t } [
"PROCEDURE square; BEGIN squ:=x*x END" \ pl0 "ebnf-parser" word-prop "block" swap at parse parse-result-remaining empty?
] unit-test
{ f } [

View File

@ -7,22 +7,52 @@ IN: peg.pl0
#! Grammar for PL/0 based on http://en.wikipedia.org/wiki/PL/0
EBNF: pl0
- = (" " | "\t" | "\n")+ => [[ drop ignore ]]
_ = (" " | "\t" | "\n")* => [[ drop ignore ]]
block = ( _ "CONST" - ident _ "=" _ number ( _ "," _ ident _ "=" _ number )* _ ";" )?
( _ "VAR" - ident ( _ "," _ ident )* _ ";" )?
( _ "PROCEDURE" - ident _ ";" ( _ block _ ";" )? )* _ statement
statement = ( ident _ ":=" _ expression | "CALL" - ident |
"BEGIN" - statement ( _ ";" _ statement )* _ "END" |
"IF" - condition _ "THEN" - statement |
"WHILE" - condition _ "DO" - statement )?
condition = "ODD" - expression |
expression _ ("=" | "#" | "<=" | "<" | ">=" | ">") _ expression
expression = ("+" | "-")? term ( _ ("+" | "-") _ term )*
term = factor ( _ ("*" | "/") _ factor )*
factor = ident | number | "(" _ expression _ ")"
ident = (([a-zA-Z])+) [[ >string ]]
digit = ([0-9]) [[ digit> ]]
number = ((digit)+) [[ unclip [ swap 10 * + ] reduce ]]
program = block "."
BEGIN = "BEGIN" _
CALL = "CALL" _
CONST = "CONST" _
DO = "DO" _
END = "END" _
IF = "IF" _
THEN = "THEN" _
ODD = "ODD" _
PROCEDURE = "PROCEDURE" _
VAR = "VAR" _
WHILE = "WHILE" _
EQ = "=" _
LTEQ = "<=" _
LT = "<" _
GT = ">" _
GTEQ = ">=" _
NEQ = "#" _
COMMA = "," _
SEMICOLON = ";" _
ASSIGN = ":=" _
ADD = "+" _
SUBTRACT = "-" _
MULTIPLY = "*" _
DIVIDE = "/" _
LPAREN = "(" _
RPAREN = ")" _
block = ( CONST ident EQ number ( COMMA ident EQ number )* SEMICOLON )?
( VAR ident ( COMMA ident )* SEMICOLON )?
( PROCEDURE ident SEMICOLON ( block SEMICOLON )? )* statement
statement = ( ident ASSIGN expression
| CALL ident
| BEGIN statement ( SEMICOLON statement )* END
| IF condition THEN statement
| WHILE condition DO statement )?
condition = ODD expression
| expression (EQ | NEQ | LTEQ | LT | GTEQ | GT) expression
expression = (ADD | SUBTRACT)? term ( (ADD | SUBTRACT) term )* _
term = factor ( (MULTIPLY | DIVIDE) factor )*
factor = ident | number | LPAREN expression RPAREN
ident = (([a-zA-Z])+) _ => [[ >string ]]
digit = ([0-9]) => [[ digit> ]]
number = ((digit)+) _ => [[ 10 digits>integer ]]
program = _ block "."
;EBNF