Artifact b45d599d08f18ee090e56aa62009f1b4dbad6c56
1 -----------------------------------------------------------------------------
2 Polemy 0.1.0
3 by k.inaba (www.kmonos.net)
4 Nov 20, 2010
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6
7
8
9 <<How to Build>>
10
11 - Install DMD
12 http://www.digitalmars.com/d/2.0/changelog.html
13 Version 2.050 is recommended. Older or newer version may not work.
14
15 - Build
16 (for Windows) Run build.bat
17 (for Unix) Run build.sh
18 or use your favorite build tools upon main.d and polemy/*.d.
19
20 Then you will get the executable "polemy" in the "bin" directory.
21
22
23
24 <<License>>
25
26 d2stacktrace/*
27
28 is written by Benjamin Thaut and licensed under 2-clause BSD License.
29 See http://3d.benjamin-thaut.de/?p=15 for the detail.
30
31 (this package is used only for enabling stack-traces during printing exceptions;
32 it is not used for release builds.)
33
34 polemy/*
35 main.d
36
37 All the other parts are written by Kazuhiro Inaba and
38 licensed under NYSL 0.9982 ( http://www.kmonos.net/nysl/ ).
39
40
41
42 <<How to Use>>
43
44 > polemy
45 starts REPL
46
47 > polemy foo.pmy
48 executes foo.pmy
49
50 > polemy -l foo.pmy
51 after executing foo.pmy, starts REPL
52
53
54
55 <<Syntax>>
56
57 Comment is "# ... \n"
58
59 E ::=
60 // declaration
61 | ("var"|"let"|"def"|LAYER) ID "=" E (";"|"in") E
62 | ("var"|"let"|"def"|LAYER) ID "(" PARAMS ")" "{" E "}" (";"|"in") E
63 | ("var"|"let"|"def"|LAYER) ID "=" E
64 | ("var"|"let"|"def"|LAYER) ID "(" PARAMS ")" "{" E "}"
65 // literal
66 | INTEGER
67 | STRING
68 | "{" ENTRYS "}"
69 | "fun" "(" PARAMS ")" "{" E "}"
70 // function call
71 | E "(" ARGS")"
72 where ARGS ::= E "," ... "," E
73 PARAMS ::= ID LAYER* "," ... "," ID LAYER*
74 ENTRYS ::= ID ":" E "," ... "," ID ":" E
75 ID ::= 'a-zA-Z0-9_...'+
76 LAYER ::= "@" ID
77 // operators
78 | "(" E ")"
79 | E "." ID
80 | E ".?" ID
81 | E BINOP E
82 | "if" "(" E ")" "{" E "}"
83 | "if" "(" E ")" "{" E "}" "else "{" E "}"
84 // layered exec
85 | LAYER "(" E ")"
86
87 The following are actually rewritten to function calls:
88
89 - if (E) then{E} else{E} ==> if( E, fun(){E}, fun(){E} )
90 - E BINOP E ==> BINOP(E, E)
91 - E.ID ==> . (E, ID)
92 - E.?ID ==> .?(E, ID)
93 - {} ==> {}()
94 - {ID:E, ...} ==> .=({...}, ID, E)
95
96 Several styles of variable declaration can be used:
97
98 - fun(x){ fun(y){x} } # K-combinator
99 - fun(x){ let f = fun(y){x} in f } # let-in style
100 - fun(x){ var f = fun(y){x}; f } # var-; style
101 - fun(x){ def f = fun(y){x} in f } # you can use any combination of (let|var|def)-(;|in)
102 - fun(x){ def f(y){x} in f } # syntax sugar for function declaration
103 - fun(x){ let f(y){x}; f } # this is also ok
104 - fun(x){ var f(y){x} } # omitting (;|in) returns the last declared object directly
105 - fun(x,y){x} #< this is not equal to the above ones. functions are no curried.
106
107 NOTE: Theres no "let rec" syntax, but still recursive definition works
108 def f(x) { if(x==0){1}else{x*f(x-1)} } in f(10) #=> 3628800
109 yet still the code below also works
110 def x=21 in def x=x+x in x #=> 42.
111 The internal scoping mechanism is a little tricky (this is for coping with
112 the "layer" feature explained below), but I hope that it works as everyone
113 expects in most cases, as long as you don't use the same-name-variables heavily :).
114
115
116
117 <<Basic Features>>
118
119 Polemy is an untyped functional programming language that has
120 - integers: 0, 123, 456666666666666666666666666666666666666789, ...
121 - strings: "hello, world!\n", ...
122 - tables: {car: 1, cdr: {car: 2, cdr: {}}}
123 - functions: fun(x){x+1}
124 as primitive datatypes. Functions capture lexical closures.
125 It is almost 'pure' (except the primitve function "print" and some
126 trick inside scoping mechanisms).
127
128
129 <<Layer>>
130
131 to be written