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mirror of https://github.com/kanaka/mal.git synced 2024-11-13 01:43:50 +03:00
mal/gnu-smalltalk/step4_if_fn_do.st
2018-06-17 19:54:54 +02:00

144 lines
3.9 KiB
Smalltalk

String extend [
String >> loadRelative [
| scriptPath scriptDirectory |
scriptPath := thisContext currentFileName.
scriptDirectory := FilePath stripFileNameFor: scriptPath.
FileStream fileIn: (FilePath append: self to: scriptDirectory)
]
]
'readline.st' loadRelative.
'util.st' loadRelative.
'types.st' loadRelative.
'reader.st' loadRelative.
'printer.st' loadRelative.
'env.st' loadRelative.
'core.st' loadRelative.
Object subclass: MAL [
MAL class >> READ: input [
^Reader readStr: input
]
MAL class >> evalAst: sexp env: env [
sexp type = #symbol ifTrue: [
^env get: sexp value
].
sexp type = #list ifTrue: [
^self evalList: sexp env: env class: MALList
].
sexp type = #vector ifTrue: [
^self evalList: sexp env: env class: MALVector
].
sexp type = #map ifTrue: [
^self evalList: sexp env: env class: MALMap
].
^sexp
]
MAL class >> evalList: sexp env: env class: aClass [
| items |
items := sexp value collect:
[ :item | self EVAL: item env: env ].
^aClass new: items
]
MAL class >> EVAL: sexp env: env [
| ast a0_ a1 a1_ a1_n a2 a3 forms function args |
sexp type ~= #list ifTrue: [
^self evalAst: sexp env: env
].
sexp value isEmpty ifTrue: [
^sexp
].
ast := sexp value.
a0_ := ast first value.
a0_ = #'def!' ifTrue: [
| result |
a1_ := ast second value.
a2 := ast third.
result := self EVAL: a2 env: env.
env set: a1_ value: result.
^result
].
a0_ = #'let*' ifTrue: [
| env_ |
env_ := Env new: env.
a1_ := ast second value.
a2 := ast third.
1 to: a1_ size by: 2 do:
[ :i | env_ set: (a1_ at: i) value
value: (self EVAL: (a1_ at: i + 1) env: env_) ].
^self EVAL: a2 env: env_
].
a0_ = #do ifTrue: [
a1_n := ast allButFirst.
^(a1_n collect: [ :item | self EVAL: item env: env]) last
].
a0_ = #if ifTrue: [
| condition |
a1 := ast second.
a2 := ast third.
a3 := ast at: 4 ifAbsent: [ MALObject Nil ].
condition := self EVAL: a1 env: env.
(condition type = #false or: [ condition type = #nil ]) ifTrue: [
^self EVAL: a3 env: env
] ifFalse: [
^self EVAL: a2 env: env
]
].
a0_ = #'fn*' ifTrue: [
| binds |
a1_ := ast second value.
binds := a1_ collect: [ :item | item value ].
a2 := ast third.
^Fn new: [ :args | self EVAL: a2 env:
(Env new: env binds: binds exprs: args) ]
].
forms := (self evalAst: sexp env: env) value.
function := forms first fn.
args := forms allButFirst asArray.
^function value: args
]
MAL class >> PRINT: sexp [
^Printer prStr: sexp printReadably: true
]
MAL class >> rep: input env: env [
^self PRINT: (self EVAL: (self READ: input) env: env)
]
]
| input historyFile replEnv |
historyFile := '.mal_history'.
ReadLine readHistory: historyFile.
replEnv := Env new: nil.
Core Ns keysAndValuesDo: [ :op :block | replEnv set: op value: block ].
MAL rep: '(def! not (fn* (a) (if a false true)))' env: replEnv.
[ input := ReadLine readLine: 'user> '. input isNil ] whileFalse: [
input isEmpty ifFalse: [
ReadLine addHistory: input.
ReadLine writeHistory: historyFile.
[ (MAL rep: input env: replEnv) displayNl ]
on: MALEmptyInput do: [ #return ]
on: MALError do:
[ :err | ('error: ', err messageText) displayNl. #return ].
]
]
'' displayNl.