- Boolean: #t for true and #f for false
- Number: Signed integer from −( 2^31 ) to 2^31
- Function
| Name |
Symbol |
Example |
| Plus |
+ |
(+ 1 2) => 3 |
| Minus |
- |
(- 1 2) => -1 |
| Multiply |
* |
(* 2 3) => 6 |
| Divide |
/ |
(/ 6 3) => 2 |
| Modulus |
mod |
(mod 8 3) => 2 |
| Greater |
> |
(> 1 2) => #f |
| Smaller |
< |
(< 1 2) => #t |
| Equal |
= |
(= 1 2) => #f |
| And |
and |
(and #t #f) => #f |
| Or |
or |
(or #t #f) => #t |
| Not |
not |
(not #t) => #f |
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define |
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fun |
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if |
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separator [ \t\n\r]
letter [a-z]
digit [0-9]
number 0|[1-9]{digit}*|-[1-9]{digit}*
ID {letter}({letter}|{digit}|"-")*
bool-val #[t|f]
- Program
PROGRAM : STMT STMTS
STMTS : STMT STMTS | {}
STMT : EXP | DEF-STMT | PRINT-STMT
- Print
PRINT_STMT : '(' print_num EXP ')'
| '(' print_bool EXP ')'
- Expression
EXPS : EXP EXPS | {}
EXP : bool_val | number | VARIABLE | NUM_OP | LOGICAL_OP | FUN_EXP | FUN_CALL | IF_EXP
- Numerical Operations
NUM_OP : PLUS | MINUS | MULTIPLY | DIVIDE | MODULES | GREATER | SMALLER | EQUAL
- Logical Operations
LOGICAL_OP : AND_OP | OR_OP | NOT_OP
- Define statement
DEF_STMT : '(' define VARIABLE EXP ')'
VARIABLE : id
- Function
FUN_EXP : '(' _fun FUN_ID FUN_BODY ')'
FUN_ID : '(' VARIABLE VARIABLES ')'
FUN_BODY : EXP
FUN_CALL : '(' FUN_EXP PARAM PARAMS ')'
| '(' FUN_NAME PARAM PARAMS ')'
PARAM : EXP
PARAMS : PARAM PARAMS
VARIABLES: VARIABLE VARIABLES
LAST_EXP : EXP
FUN_NAME : id
- If Expression
IF_EXP : '(' _if TEST_EXP THAN_EXP ELSE_EXP ')'
TEST_EXP: EXP
THAN_EXP: EXP
ELSE_EXP: EXP