diff options
| author | Case Duckworth | 2024-03-19 22:20:42 -0500 |
|---|---|---|
| committer | Case Duckworth | 2024-03-19 22:20:42 -0500 |
| commit | dd483e481c5cb5e2bf5aa7fba21bdb1a2d85fc9c (patch) | |
| tree | 99e391db9f209f7fca8db8e9aa8edbbb05cff28d | |
| parent | A new start! (diff) | |
| download | lam-new-start.tar.gz lam-new-start.zip | |
Remove need for `lambda` to include an implicit `begin` new-start
This way i can write begin in terms of lambda
| -rw-r--r-- | base.lua | 8 | ||||
| -rw-r--r-- | eval.lua | 15 |
2 files changed, 8 insertions, 15 deletions
| diff --git a/base.lua b/base.lua index 9c5b5b7..6dc71e4 100644 --- a/base.lua +++ b/base.lua | |||
| @@ -5,14 +5,6 @@ local type = require "type" | |||
| 5 | local isNull = type.isNull | 5 | local isNull = type.isNull |
| 6 | 6 | ||
| 7 | base.env = { | 7 | base.env = { |
| 8 | begin = | ||
| 9 | function (r) | ||
| 10 | local r = r | ||
| 11 | while not isNull(r.cdr) do | ||
| 12 | r = r.cdr | ||
| 13 | end | ||
| 14 | return r.car | ||
| 15 | end, | ||
| 16 | ["+"] = | 8 | ["+"] = |
| 17 | function (r) | 9 | function (r) |
| 18 | local r, a = r, 0 | 10 | local r, a = r, 0 |
| diff --git a/eval.lua b/eval.lua index e926bc4..565ead5 100644 --- a/eval.lua +++ b/eval.lua | |||
| @@ -32,9 +32,13 @@ function eval.Proc (params, body, env) | |||
| 32 | p, a = p.cdr, a.cdr | 32 | p, a = p.cdr, a.cdr |
| 33 | end | 33 | end |
| 34 | pp.pp(self.body) | 34 | pp.pp(self.body) |
| 35 | return eval.eval( | 35 | local b = self.body |
| 36 | self.body, | 36 | local e = eval.Env(inner, self.env) |
| 37 | eval.Env(inner, self.env)) | 37 | while not isNull(b.cdr) do |
| 38 | eval.eval(b.car, e) | ||
| 39 | b = b.cdr | ||
| 40 | end | ||
| 41 | return eval.eval(b.car, e) | ||
| 38 | end, | 42 | end, |
| 39 | } | 43 | } |
| 40 | return setmetatable(v, mt) | 44 | return setmetatable(v, mt) |
| @@ -54,10 +58,7 @@ function eval.eval (x, env) | |||
| 54 | env[args.car] = eval.eval(args.cdr.car, env) | 58 | env[args.car] = eval.eval(args.cdr.car, env) |
| 55 | return nil | 59 | return nil |
| 56 | elseif op == "lambda" or op == "lam" then | 60 | elseif op == "lambda" or op == "lam" then |
| 57 | return eval.Proc( | 61 | return eval.Proc(args.car, args.cdr, env) |
| 58 | args.car, | ||
| 59 | Cons("begin", args.cdr), -- i don't like this | ||
| 60 | env) | ||
| 61 | elseif op == "if" then | 62 | elseif op == "if" then |
| 62 | assert(not isNull(args.cdr), "Malformed 'if'") | 63 | assert(not isNull(args.cdr), "Malformed 'if'") |
| 63 | local test, conseq, alt = | 64 | local test, conseq, alt = |