summary refs log tree commit diff stats
path: root/doc/grammar.txt
blob: 1e54d1116ace13dde3f02ae12bc94dad64e7da93 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
module ::= ([COMMENT] [SAD] stmt)*

comma ::= ',' [COMMENT] [IND]
semicolon ::= ';' [COMMENT] [IND]

operator ::=  OP0 | OP1 | OP2 | OP3 | OP4 | OP5 | OP6 | OP7 | OP8 | OP9
           | 'or' | 'xor' | 'and'
           | 'is' | 'isnot' | 'in' | 'notin' | 'of'
           | 'div' | 'mod' | 'shl' | 'shr' | 'not' | 'addr' | 'static' | '..'

prefixOperator ::= operator

optInd ::= [COMMENT] [IND]
optPar ::= [IND] | [SAD]

lowestExpr ::= assignExpr (OP0 optInd assignExpr)*
assignExpr ::= orExpr (OP1 optInd orExpr)*
orExpr ::= andExpr (OP2 optInd andExpr)*
andExpr ::= cmpExpr (OP3 optInd cmpExpr)*
cmpExpr ::= sliceExpr (OP4 optInd sliceExpr)*
sliceExpr ::= ampExpr (OP5 optInd ampExpr)*
ampExpr ::= plusExpr (OP6 optInd plusExpr)*
plusExpr ::= mulExpr (OP7 optInd mulExpr)*
mulExpr ::= dollarExpr (OP8 optInd dollarExpr)*
dollarExpr ::= primary (OP9 optInd primary)*

indexExpr ::= expr

castExpr ::= 'cast' '[' optInd typeDesc optPar ']' '(' optInd expr optPar ')'
symbol ::= '`' (KEYWORD | IDENT | operator | '(' ')' | '[' ']' | '{' '}'
               | '=' | literal)+ '`'
         | IDENT
         
primaryPrefix ::= (prefixOperator | 'bind') optInd
primarySuffix ::= '.' optInd symbol [generalizedLit]
                | '(' optInd namedExprList optPar ')'
                | '[' optInd [indexExpr (comma indexExpr)* [comma]] optPar ']'
                | '{' optInd [indexExpr (comma indexExpr)* [comma]] optPar '}'

primary ::= primaryPrefix* (symbol [generalizedLit] | 
                            constructor | castExpr)
            primarySuffix*

generalizedLit ::= GENERALIZED_STR_LIT | GENERALIZED_TRIPLESTR_LIT

literal ::= INT_LIT | INT8_LIT | INT16_LIT | INT32_LIT | INT64_LIT
          | UINT_LIT | UINT8_LIT | UINT16_LIT | UINT32_LIT | UINT64_LIT
          | FLOAT_LIT | FLOAT32_LIT | FLOAT64_LIT
          | STR_LIT | RSTR_LIT | TRIPLESTR_LIT
          | CHAR_LIT
          | NIL

constructor ::= literal
          | '[' optInd colonExprList optPar ']'
          | '{' optInd ':' | colonExprList optPar '}'
          | '(' optInd colonExprList optPar ')'

colonExpr ::= expr [':' expr]
colonExprList ::= [colonExpr (comma colonExpr)* [comma]]

namedExpr ::= expr ['=' expr]
namedExprList ::= [namedExpr (comma namedExpr)* [comma]]

exprOrType ::= lowestExpr
            | 'if' expr ':' expr ('elif' expr ':' expr)* 'else' ':' expr
            | 'var' exprOrType
            | 'ref' exprOrType
            | 'ptr' exprOrType
            | 'type' exprOrType
            | 'tuple' tupleDesc

expr ::= exprOrType
     | 'proc' paramList [pragma] ['=' stmt] 

exprList ::= [expr (comma expr)* [comma]]


qualifiedIdent ::= symbol ['.' symbol]

typeDesc ::= exprOrType
         | 'proc' paramList [pragma]

macroStmt ::= ':' [stmt] ('of' [exprList] ':' stmt
                         |'elif' expr ':' stmt
                         |'except' exceptList ':' stmt )*
                         ['else' ':' stmt]

pragmaBlock ::= pragma [':' stmt]

simpleStmt ::= returnStmt
             | yieldStmt
             | discardStmt
             | raiseStmt
             | breakStmt
             | continueStmt
             | pragmaBlock
             | importStmt
             | fromStmt
             | includeStmt
             | exprStmt
complexStmt ::= ifStmt | whileStmt | caseStmt | tryStmt | forStmt
              | blockStmt | staticStmt | asmStmt
              | procDecl | iteratorDecl | macroDecl | templateDecl | methodDecl
              | constSection | letSection | varSection
              | typeSection | whenStmt | bindStmt

indPush ::= IND # and push indentation onto the stack
indPop ::= # pop indentation from the stack

stmt ::= simpleStmt [SAD]
 | indPush (complexStmt | simpleStmt)
  ([SAD] (complexStmt | simpleStmt))*
   DED indPop

exprStmt ::= lowestExpr ['=' expr | [expr (comma expr)*] [macroStmt]]
returnStmt ::= 'return' [expr]
yieldStmt ::= 'yield' expr
discardStmt ::= 'discard' expr
raiseStmt ::= 'raise' [expr]
breakStmt ::= 'break' [symbol]
continueStmt ::= 'continue'
ifStmt ::= 'if' expr ':' stmt ('elif' expr ':' stmt)* ['else' ':' stmt]
whenStmt ::= 'when' expr ':' stmt ('elif' expr ':' stmt)* ['else' ':' stmt]
caseStmt ::= 'case' expr [':'] ('of' exprList ':' stmt)*
                               ('elif' expr ':' stmt)*
                               ['else' ':' stmt]
whileStmt ::= 'while' expr ':' stmt
forStmt ::= 'for' symbol (comma symbol)* 'in' expr ':' stmt
exceptList ::= [qualifiedIdent (comma qualifiedIdent)*]

tryStmt ::= 'try' ':' stmt
           ('except' exceptList ':' stmt)*
           ['finally' ':' stmt]
asmStmt ::= 'asm' [pragma] (STR_LIT | RSTR_LIT | TRIPLESTR_LIT)
blockStmt ::= 'block' [symbol] ':' stmt
staticStmt ::= 'static' ':' stmt
filename ::= symbol | STR_LIT | RSTR_LIT | TRIPLESTR_LIT
importStmt ::= 'import' filename (comma filename)*
includeStmt ::= 'include' filename (comma filename)*
bindStmt ::= 'bind' qualifiedIdent (comma qualifiedIdent)*
fromStmt ::= 'from' filename 'import' symbol (comma symbol)*

pragma ::= '{.' optInd (colonExpr [comma])* optPar ('.}' | '}')

param ::= symbol (comma symbol)* (':' typeDesc ['=' expr] | '=' expr)
paramList ::= ['(' [param (comma|semicolon param)*] optPar ')'] [':' typeDesc]

genericConstraint ::= 'object' | 'tuple' | 'enum' | 'proc' | 'ref' | 'ptr' 
                    | 'var' | 'distinct' | primary
genericConstraints ::= genericConstraint ( '|' optInd genericConstraint )*

genericParam ::= symbol [':' genericConstraints] ['=' expr]
genericParams ::= '[' genericParam (comma|semicolon genericParam)* optPar ']'


routineDecl := symbol ['*'] [genericParams] paramList [pragma] ['=' stmt]
procDecl ::= 'proc' routineDecl
macroDecl ::= 'macro' routineDecl
iteratorDecl ::= 'iterator' routineDecl
templateDecl ::= 'template' routineDecl
methodDecl ::= 'method' routineDecl

colonAndEquals ::= [':' typeDesc] '=' expr

constDecl ::= symbol ['*'] [pragma] colonAndEquals [COMMENT | IND COMMENT]
            | COMMENT
constSection ::= 'const' indPush constDecl (SAD constDecl)* DED indPop
letSection ::= 'let' indPush constDecl (SAD constDecl)* DED indPop

typeDef ::= typeDesc | objectDef | enumDef | 'distinct' typeDesc

objectField ::= symbol ['*'] [pragma]
objectIdentPart ::= objectField (comma objectField)* ':' typeDesc
                    [COMMENT|IND COMMENT]

objectWhen ::= 'when' expr ':' [COMMENT] objectPart
              ('elif' expr ':' [COMMENT] objectPart)*
              ['else' ':' [COMMENT] objectPart]
objectCase ::= 'case' expr ':' typeDesc [COMMENT]
              ('of' exprList ':' [COMMENT] objectPart)*
              ['else' ':' [COMMENT] objectPart]

objectPart ::= objectWhen | objectCase | objectIdentPart | 'nil'
             | indPush objectPart (SAD objectPart)* DED indPop
tupleDesc ::= '[' optInd [param (comma|semicolon param)*] optPar ']'

objectDef ::= 'object' [pragma] ['of' typeDesc] objectPart
enumField ::= symbol ['=' expr]
enumDef ::= 'enum' (enumField [comma] [COMMENT | IND COMMENT])+

typeDecl ::= COMMENT
           | symbol ['*'] [genericParams] ['=' typeDef] [COMMENT | IND COMMENT]

typeSection ::= 'type' indPush typeDecl (SAD typeDecl)* DED indPop

colonOrEquals ::= ':' typeDesc ['=' expr] | '=' expr
varField ::= symbol ['*'] [pragma]
varPart ::= symbol (comma symbol)* colonOrEquals [COMMENT | IND COMMENT]
varSection ::= 'var' (varPart
                   | indPush (COMMENT|varPart)
                     (SAD (COMMENT|varPart))* DED indPop)