summary refs log tree commit diff stats
path: root/compiler/semfields.nim
blob: 6002705b38657dd5b397f0b74ca7dbd9945251a1 (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
<
#
#
#           The Nim Compiler
#        (c) Copyright 2015 Andreas Rumpf
#
#    See the file "copying.txt", included in this
#    distribution, for details about the copyright.
#

## This module does the semantic transformation of the fields* iterators.
#  included from semstmts.nim

type
  TFieldInstCtx = object  # either 'tup[i]' or 'field' is valid
    tupleType: PType      # if != nil we're traversing a tuple
    tupleIndex: int
    field: PSym
    replaceByFieldName: bool

proc instFieldLoopBody(c: TFieldInstCtx, n: PNode, forLoop: PNode): PNode =
  case n.kind
  of nkEmpty..pred(nkIdent), succ(nkSym)..nkNilLit: result = n
  of nkIdent, nkSym:
    result = n
    let ident = considerQuotedIdent(n)
    var L = sonsLen(forLoop)
    if c.replaceByFieldName:
      if ident.id == considerQuotedIdent(forLoop[0]).id:
        let fieldName = if c.tupleType.isNil: c.field.name.s
                        elif c.tupleType.n.isNil: "Field" & $c.tupleIndex
                        else: c.tupleType.n.sons[c.tupleIndex].sym.name.s
        result = newStrNode(nkStrLit, fieldName)
        return
    # other fields:
    for i in ord(c.replaceByFieldName)..L-3:
      if ident.id == considerQuotedIdent(forLoop[i]).id:
        var call = forLoop.sons[L-2]
        var tupl = call.sons[i+1-ord(c.replaceByFieldName)]
        if c.field.isNil:
          result = newNodeI(nkBracketExpr, n.info)
          result.add(tupl)
          result.add(newIntNode(nkIntLit, c.tupleIndex
xpr, n.info) result.add(tupl) result.add(newSymNode(c.field, n.info)) break else: if n.kind == nkContinueStmt: localError(n.info, errGenerated, "'continue' not supported in a 'fields' loop") result = copyNode(n) newSons(result, sonsLen(n)) for i in countup(0, sonsLen(n)-1): result.sons[i] = instFieldLoopBody(c, n.sons[i], forLoop) type TFieldsCtx = object c: PContext m: TMagic proc semForObjectFields(c: TFieldsCtx, typ, forLoop, father: PNode) = case typ.kind of nkSym: var fc: TFieldInstCtx # either 'tup[i]' or 'field' is valid fc.field = typ.sym fc.replaceByFieldName = c.m == mFieldPairs openScope(c.c) inc c.c.inUnrolledContext let body = instFieldLoopBody(fc, lastSon(forLoop), forLoop) father.add(semStmt(c.c, body)) dec c.c.inUnrolledContext closeScope(c.c) of nkNilLit: discard of nkRecCase: let L = forLoop.len let call = forLoop.sons[L-2] if call.len > 2: localError(forLoop.info, errGenerated, "parallel 'fields' iterator does not work for 'case' objects") return # iterate over the selector: semForObjectFields(c, typ[0], forLoop, father) # we need to generate a case statement: var caseStmt = newNodeI(nkCaseStmt, forLoop.info) # generate selector: var access = newNodeI(nkDotExpr, forLoop.info, 2) access.sons[0] = call.sons[1] access.sons[1] = newSymNode(typ.sons[0].sym, forLoop.info) caseStmt.add(semExprWithType(c.c, access)) # copy the branches over, but replace the fields with the for loop body: for i in 1 .. <typ.len: var branch = copyTree(typ[i]) let L = branch.len branch.sons[L-1] = newNodeI(nkStmtList, forLoop.info) semForObjectFields(c, typ[i].lastSon, forLoop, branch[L-1]) caseStmt.add(branch) father.add(caseStmt) of nkRecList: for t in items(typ): semForObjectFields(c, t, forLoop, father) else: illFormedAstLocal(typ) proc semForFields(c: PContext, n: PNode, m: TMagic): PNode = # so that 'break' etc. work as expected, we produce # a 'while true: stmt; break' loop ... result = newNodeI(nkWhileStmt, n.info, 2) var trueSymbol = strTableGet(magicsys.systemModule.tab, getIdent"true") if trueSymbol == nil: localError(n.info, errSystemNeeds, "true") trueSymbol = newSym(skUnknown, getIdent"true", getCurrOwner(c), n.info) trueSymbol.typ = getSysType(tyBool) result.sons[0] = newSymNode(trueSymbol, n.info) var stmts = newNodeI(nkStmtList, n.info) result.sons[1] = stmts var length = sonsLen(n) var call = n.sons[length-2] if length-2 != sonsLen(call)-1 + ord(m==mFieldPairs): localError(n.info, errWrongNumberOfVariables) return result const skippedTypesForFields = abstractVar - {tyTypeDesc} + tyUserTypeClasses var tupleTypeA = skipTypes(call.sons[1].typ, skippedTypesForFields) if tupleTypeA.kind notin {tyTuple, tyObject}: localError(n.info, errGenerated, "no object or tuple type") return result for i in 1..call.len-1: var tupleTypeB = skipTypes(call.sons[i].typ, skippedTypesForFields) if not sameType(tupleTypeA, tupleTypeB): typeMismatch(call.sons[i].info, tupleTypeA, tupleTypeB) inc(c.p.nestedLoopCounter) if tupleTypeA.kind == tyTuple: var loopBody = n.sons[length-1] for i in 0..sonsLen(tupleTypeA)-1: openScope(c) var fc: TFieldInstCtx fc.tupleType = tupleTypeA fc.tupleIndex = i fc.replaceByFieldName = m == mFieldPairs var body = instFieldLoopBody(fc, loopBody, n) inc c.inUnrolledContext stmts.add(semStmt(c, body)) dec c.inUnrolledContext closeScope(c) else: var fc: TFieldsCtx fc.m = m fc.c = c var t = tupleTypeA while t.kind == tyObject: semForObjectFields(fc, t.n, n, stmts) if t.sons[0] == nil: break t = skipTypes(t.sons[0], skipPtrs) dec(c.p.nestedLoopCounter) # for TR macros this 'while true: ...; break' loop is pretty bad, so # we avoid it now if we can: if containsNode(stmts, {nkBreakStmt}): var b = newNodeI(nkBreakStmt, n.info) b.add(ast.emptyNode) stmts.add(b) else: result = stmts