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(define-library (csc ir1)
(export
call-arguments
call-procedure
call?
constant-expression
constant?
if-alternate
if-consequent
if-test
if?
lambda-body
lambda-case-alternate
lambda-case-arguments
lambda-case-body
lambda-case-gensyms
lambda-case-rest
lambda-case?
lambda?
letrec-expression
letrec-gensyms
letrec-in-order?
letrec-names
letrec-values
letrec?
lexical-ref-gensym
lexical-ref-name
lexical-ref?
lexical-set-expression
lexical-set-gensym
lexical-set-name
lexical-set?
library-ref-library
library-ref-name
library-ref-public?
library-ref?
library-set-expression
library-set-library
library-set-name
library-set-public?
library-set?
make-call
make-constant
make-if
make-lambda
make-lambda-case
make-letrec
make-lexical-ref
make-lexical-set
make-library-ref
make-library-set
make-sequence
make-toplevel-define
make-void
sequence-head
sequence-tail
sequence?
toplevel-define-expression
toplevel-define-name
toplevel-define?
void?)
(import (scheme base))
(begin
; This library defines the intermediate representation IR1. An expression
; in IR1 has one of the following forms (plagiarized from Guile's
; Tree-IL).
; <void>
; An empty expression. In practice, equivalent to Scheme's (if #f #f).
(define-record-type <void>
(make-void)
void?)
; <constant> expression
; Constant is used to include literal constants in scheme code.
(define-record-type <constant>
(make-constant expression)
constant?
(expression constant-expression))
; <lexical-ref> name gensym
; A reference to a lexically-bound variable. The name is the original name
; of the variable in the source program. gensym is a unique identifier for
; this variable.
(define-record-type <lexical-ref>
(make-lexical-ref name gensym)
lexical-ref?
(name lexical-ref-name)
(gensym lexical-ref-gensym))
; <lexical-set> name gensym expression
; Sets a lexically-bound variable.
(define-record-type <lexical-set>
(make-lexical-set name gensym expression)
lexical-set?
(name lexical-set-name)
(gensym lexical-set-gensym)
(expression lexical-set-expression))
; <library-ref> library name public?
; A reference to a variable in a specific library. library should be the name
; of the library, e.g. (scheme base).
;
; If public? is true, name will be looked up in library's public interface,
; otherwise it will be looked up among the library's private bindings.
(define-record-type <library-ref>
(make-library-ref library name public?)
library-ref?
(library library-ref-library)
(name library-ref-name)
(public? library-ref-public?))
; <library-set> library name public? expression
; Sets a variable in a specific library.
(define-record-type <library-set>
(make-library-set library name public? expression)
library-set?
(library library-set-library)
(name library-set-name)
(public? library-set-public?)
(expression library-set-expression))
; <toplevel-define> name expression
; Defines a new variable in the current library.
(define-record-type <toplevel-define>
(make-toplevel-define name expression)
toplevel-define?
(name toplevel-define-name)
(expression toplevel-define-expression))
; <if> test consequent alternate
; A conditional.
(define-record-type <if>
(make-if test consequent alternate)
if?
(test if-test)
(consequent if-consequent)
(alternate if-alternate))
; <call> procedure arguments
; A procedure call. The procedure and arguments are evaluated in an
; unspecified order, and the resulting procedure is passed the
; resulting arguments.
(define-record-type <call>
(make-call procedure arguments)
call?
(procedure call-procedure)
(arguments call-arguments))
; <sequence> head tail
; Evaluate head, ignoring any result. Then tail is evaluated.
(define-record-type <sequence>
(make-sequence head tail)
sequence?
(head sequence-head)
(tail sequence-tail))
; <lambda> body
; A closure. body is an expression of type <lambda-case>.
(define-record-type <lambda>
(make-lambda body)
lambda?
(body lambda-body))
; <lambda-case> arguments rest gensyms body alternate
; One clause of a case-lambda. A lambda expression in Scheme is treated as
; a case-lambda with one clause.
;
; arguments is a list of the procedures arguments, as symbols. rest is the
; name of the rest argument, or #f. gensyms is a list of gensyms
; corresponding to all arguments: first all of the normal arguments, then
; the rest argument if any.
;
; body is the name of the clause. If the procedure is called with an
; appropriate number of arguments, body is evaluated in tail position.
; Otherwise if there is an alternate, it should be a <lambda-case>
; expression, representing the next clause to try. If there is no
; alternate, an error is signaled.
(define-record-type <lambda-case>
(make-lambda-case arguments rest gensyms body alternate)
lambda-case?
(arguments lambda-case-arguments)
(rest lambda-case-rest)
(gensyms lambda-case-gensyms)
(body lambda-case-body)
(alternate lambda-case-alternate))
; <letrec> in-order? names gensyms values expression
; Lexical binding, like Scheme's letrec, or letrec* if in-order? is true.
; names are the original binding names, gensyms are gensyms corresponding
; to the names, and values are IR1 expressions for the values. expression
; is a single IR1 expression.
(define-record-type <letrec>
(make-letrec in-order? names gensyms values expression)
letrec?
(in-order? letrec-in-order?)
(names letrec-names)
(gensyms letrec-gensyms)
(values letrec-values)
(expression letrec-expression))))
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