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| author | Chouser <chouser@n01se.net> | 2015-02-14 13:40:07 -0500 |
|---|---|---|
| committer | Chouser <chouser@n01se.net> | 2015-02-21 13:22:44 -0500 |
| commit | 69972a8399efe4abb8567526e90262e131f90d26 (patch) | |
| tree | 5e12e86da119a9c3f4372dab9e04777a746f90d0 /forth/env.fs | |
| parent | 9da223a35a176d94fbb75cbcc1000871ff5aff0b (diff) | |
| download | mal-69972a8399efe4abb8567526e90262e131f90d26.tar.gz mal-69972a8399efe4abb8567526e90262e131f90d26.zip | |
forth: Add step 3
Diffstat (limited to 'forth/env.fs')
| -rw-r--r-- | forth/env.fs | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/forth/env.fs b/forth/env.fs new file mode 100644 index 0000000..c1dc278 --- /dev/null +++ b/forth/env.fs @@ -0,0 +1,45 @@ +require types.fs + +MalType% + cell% field MalEnv/outer + cell% field MalEnv/data +deftype MalEnv + +: MalEnv. { outer -- env } + MalEnv new { env } + outer env MalEnv/outer ! + MalMap/Empty env MalEnv/data ! + env ; + +: env/set { key val env -- } + key val env MalEnv/data @ assoc + env MalEnv/data ! ; + +: env/find { key env -- env-or-0 } + env + begin ( env ) + dup 0 key rot MalEnv/data @ get ( env val-or-0 ) + 0= if ( env ) + MalEnv/outer @ dup 0= ( env-or-0 done-looping? ) + else + -1 \ found it! ( env -1 ) + endif + until ; + +MalEnv + extend get { not-found key env -- } + key env env/find ( env-or-0 ) + ?dup 0= if + not-found + else ( env ) + not-found key rot MalEnv/data @ get + endif ;; + extend pr-buf { env } + env MalEnv/data @ pr-buf + a-space s" outer: " str-append + env MalEnv/outer @ ?dup 0= if + s" <none>" str-append + else + pr-buf + endif ;; +drop
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