Language "IBAFlang"

# 1: General expressions
Syntax Exp:exp ::= id
                 | int
                 | 'true'
                 | 'false'
                 | exp '+' exp
                 | exp '-' exp
                 | exp '*' exp
                 | exp '/' exp
                 | exp '%' exp
                 | exp '&&' exp
                 | exp '||' exp
                 | exp '==' exp
                 | exp '>=' exp
                 | exp '>' exp
                 | exp '<=' exp
                 | exp '<' exp
                 | id '(' paramvalues? ')'
                 | '(' exp ')'

Syntax ParamValues: paramvalues ::= exp (',' paramvalues)?

Semantics eval-exp[[ _:exp ]] : => values
Rule eval-exp[[ Id ]] = assigned(bound(id[[ Id ]]))
Rule eval-exp[[ Int ]] = int-val[[ Int ]]
Rule eval-exp[[ 'true' ]] = true
Rule eval-exp[[ 'false' ]] = false
Rule eval-exp[[ Exp1 '+' Exp2 ]] = int-add(eval-exp[[ Exp1 ]], eval-exp[[ Exp2 ]])
Rule eval-exp[[ Exp1 '-' Exp2 ]] = integer-subtract(eval-exp[[ Exp1 ]], eval-exp[[ Exp2 ]]) // For some reason the funcon interpreter doesn't recognise the alias `int-sub` :/
Rule eval-exp[[ Exp1 '*' Exp2 ]] = int-mul(eval-exp[[ Exp1 ]], eval-exp[[ Exp2 ]])
Rule eval-exp[[ Exp1 '/' Exp2 ]] = checked int-div(eval-exp[[ Exp1 ]], eval-exp[[ Exp2 ]])
Rule eval-exp[[ Exp1 '%' Exp2 ]] = checked int-mod(eval-exp[[ Exp1 ]], eval-exp[[ Exp2 ]])
Rule eval-exp[[ Exp1 '&&' Exp2 ]] = and(eval-exp[[ Exp1 ]], eval-exp[[ Exp2 ]])
Rule eval-exp[[ Exp1 '||' Exp2 ]] = and(eval-exp[[ Exp1 ]], eval-exp[[ Exp2 ]])
Rule eval-exp[[ Exp1 '==' Exp2 ]] = is-equal(eval-exp[[ Exp1 ]], eval-exp[[ Exp2]] )
Rule eval-exp[[ Exp1 '>=' Exp2 ]] = is-greater-or-equal(eval-exp[[ Exp1 ]], eval-exp[[ Exp2]] )
Rule eval-exp[[ Exp1 '>' Exp2 ]] = is-greater(eval-exp[[ Exp1 ]], eval-exp[[ Exp2]] )
Rule eval-exp[[ Exp1 '<=' Exp2 ]] = is-less-or-equal(eval-exp[[ Exp1 ]], eval-exp[[ Exp2]] )
Rule eval-exp[[ Exp1 '<' Exp2 ]] = is-less(eval-exp[[ Exp1 ]], eval-exp[[ Exp2]] )
Rule eval-exp[[ Id '(' ParamValues? ')' ]] = handle-return apply(bound id[[ Id ]], eval-params[[ ParamValues? ]])
Rule eval-exp[[ '(' Exp ')' ]] = eval-exp[[ Exp ]]

Semantics eval-params[[ _:paramvalues? ]] : lists(values)
Rule eval-params[[ ]] = []
Rule eval-params[[ Exp ]] = list(eval-exp[[ Exp ]])
Rule eval-params[[ Exp ',' ParamValues ]] = cons(eval-exp[[ Exp ]], eval-params[[ ParamValues ]])


Lexis Id:id ::= ('a'-'z' | 'A'-'Z') ('a'-'z' | 'A'-'Z' | '0'-'9')*

Semantics id[[ _:id ]] : identifiers
Rule id[[ Id ]] = \"Id\"


Syntax Int:int ::= '0' | ('-'?_decimal)

Semantics int-val[[ _:int ]] : ints
Rule int-val[[ '0' ]] = 0
Rule int-val[[ Dec ]] = dec-val[[ Dec ]]
Rule int-val[[ '-' Dec ]] = integer-negate(dec-val[[ Dec ]])


Lexis Dec:decimal ::= '1'-'9'('0'-'9')*

Semantics dec-val[[ _:decimal ]] : ints
Rule dec-val[[ Dec ]] = decimal-natural(\"Dec\")